The conditionally replicative adenovirus Ad5/3-Δ24 has a type-3 knob incorporated into the type-5 fiber that facilitates enhanced ovarian cancer infectivity. Preclinical studies have shown that Ad5/3-Δ24 achieves significant oncolysis and antitumor activity in ovarian cancer models. The purpose of this study was to evaluate in a Phase I trial the feasibility and safety of intraperitoneal (IP) Ad5/3-Δ24 in recurrent ovarian cancer patients.
Eligible patients were treated with IP Ad5/3-Δ24 for 3 consecutive days in one of three dose cohorts ranging 1 × 1010–1 × 1012 vp. Toxicity was assessed utilizing CTC grading and efficacy with RECIST. Ascites, serum, and other samples were obtained to evaluate gene transfer, generation of wildtype virus, viral shedding, and antibody response.
Nine of 10 patients completed treatment per protocol. A total of 15 vector-related adverse events were experienced in 5 patients. These events included fever or chills, nausea, fatigue, and myalgia. All were grade 1–2 in nature, transient, and medically managed. Of the 8 treated patients evaluable for response, six patients had stable disease and 2 patients had progressive disease. Three patients had decreased CA-125 from pretreatment levels one month after treatment. Ancillary biologic studies indicated Ad5/3-Δ24 replication in patients in the higher dose cohorts. All patients experienced an anti-adenoviral neutralizing antibody effect.
This study suggests the feasibility and safety of a serotype chimeric infectivity-enhanced CRAd, Ad5/3-Δ24, as a potential therapeutic option for recurrent ovarian cancer patients.
CRAd; gene therapy; infectivity-enhanced adenoviral vectors; ovarian cancer
Ad5.SSTR/TK.RGD is an infectivity-enhanced adenovirus expressing a therapeutic thymidine kinase suicide gene and a somatostatin receptor that allows for noninvasive gene transfer imaging. The purpose of this study was to identify the MTD, toxicities, clinical efficacy and biologic effects of Ad5.SSTR/TK.RGD in patients with recurrent gynecologic cancer.
Eligible patients were treated intraperitoneally (IP) for 3 days with 1×109 to 1×1012 vp/dose of Ad5.SSTR/TK.RGD followed by intravenous ganciclovir for 14 days. Toxicity and clinical efficacy were assessed utilizing CTC Adverse Events grading and RECIST criteria. Imaging utilizing In-111 pentetreotide was obtained before and after treatment. Tissue samples were obtained to evaluate for gene transfer, generation of wild-type virus, viral shedding and antibody response.
Twelve patients were treated in three cohorts. The most common vector-related clinical toxicities were grade 1–2 constitutional or pain symptoms, experienced most often in patients treated at the highest dose. MTD was not identified. Five patients demonstrated stable disease; all others experienced progressive disease. One patient with stable disease experienced complete resolution of disease and normalization of CA125 on further follow-up. Imaging detected increased In-111 pentetreotide retention in patients treated at the highest dose. Ancillary studies demonstrated presence of Ad5.SSTR/TK.RGD virus and HSV1-tk expression in ascites samples collected at various time points in most patients treated within the higher dose cohorts.
This study demonstrates the safety, potential efficacy, and possible gene transfer imaging capacity of Ad5.SSTR/TK.RGD in patients with recurrent gynecologic cancer. Further development of this novel gene therapeutic appears to be warranted.
Suicide gene therapy; gene transfer imaging; infectivity enhanced adenoviral vectors; ovarian cancer; endometrial cancer
Conditionally replicative adenoviral (CRAd) virotherapy represents a promising therapeutic approach for cancer. We have demonstrated that a serotype chimeric adenoviral 5/3 fiber-knob modification achieves enhanced ovarian cancer infectivity, conditional replication, and oncolytic activity. This study evaluated the safety of intraperitoneal (IP) Ad5/3-Δ24 in advance of a phase I clinical trial in gynecologic cancers. Syrian hamster cohorts were treated with IP Ad5/3-Δ24 or control buffer for 3 consecutive days and euthanized on study days 8, 17, 57, and 89. Blood and tissue samples were harvested from each animal. For biodistribution studies, presence and quantitation of viral levels within samples were determined via quantitative polymerase chain reaction. For safety studies, animals were assessed for adverse vector-related tissue or laboratory effects. In the biodistribution study, low levels of Ad5/3-Δ24 DNA were noted outside of the abdominal cavity. Viral DNA levels in tissues obtained from the peritoneal cavity peaked at day 8 and declined thereafter. In the safety study, no specific histopathologic changes were attributable to virus administration. Hematologic findings noted in the 1 × 1011 viral particles (vp)/dose group on Days 4 and/or 8 were indicative of an Ad5/3-Δ24–specific generalized inflammatory response; these findings resolved by day 56. The no observable adverse effect level was determined to be 1 × 1010 vp/dose. This study elucidates the safety profile of IP administration of the serotype chimeric infectivity-enhanced CRAd, Ad5/3-Δ24, and provides guidance for a planned phase I trial for patients with recurrent gynecologic cancers.
In this study, Kim and colleagues evaluate the biodistribution, safety, and immunological response associated with intraperitoneal administration of a novel adenoviral vector with a 5/3 fiber-knob modification in a hamster model. These studies were done in advance of a planned phase I human clinical trial in ovarian and other select gynecological cancers.
To determine the maximum tolerated dose (MTD), toxicity spectrum, clinical activity, and biological effects of the tropism-modified infectivity-enhanced CRAd, Ad5-Δ24-RGD, in patients with gynecologic malignancies.
Cohorts of eligible patients were treated daily for 3 days via intraperitoneal catheter. Vector doses ranged from 1×109 to 1×1012 viral particles/day. Toxicity was evaluated utilizing CTCv3.0. CA-125 and RECIST criteria were utilized to determine clinical efficacy. Corollary biologic studies included assessment of CRAd replication, wild type virus generation, viral shedding, and neutralizing antibody response.
Twenty-one patients were enrolled. Adverse clinical effects were limited to G1/2 fever, fatigue, or abdominal pain. No vector related grade 3/4 toxicities were noted. No clinically significant laboratory abnormalities were noted. The MTD was not reached. Over a 1 month follow up, 15 (71%) patients had stable disease and six (29%) had progressive disease. No partial or complete responses were noted. Seven patients had a decrease in CA-125; 4 had a >20% drop. RGD-specific-PCR demonstrated the presence of study vector in ascites of 16 patients. Seven revealed an increase in virus after day 3, suggesting replication of Ad5-Δ24-RGD. Minimal wild type virus generation was detected. Viral shedding studies demonstrated insignificant shedding in the serum, saliva, and urine. Anti-adenoviral neutralizing antibody effects were prevalent.
This study, the first to evaluate an infectivity enhanced CRAd in human cancer, demonstrates the feasibility, safety, potential antitumor response, and biologic activity of this approach in ovarian cancer. Further evaluation of infectivity enhanced virotherapy approaches for gynecologic malignancies is warranted.
Ovarian cancer; Gene therapy; Virotherapy; Replicative Adenovirus; CRAd
Clinical studies suggest that responses to HPV16 E6E7L2 fusion protein (TA-CIN) vaccination alone are modest, and GPI-0100 is a well-tolerated, potent adjuvant. Here we sought to optimize both the immunogenicity of TA-CIN via formulation with GPI-0100 and treatment of HPV16+ cancer by vaccination after cisplatin chemotherapy. HPV16 neutralizing serum antibody titers, CD4+ T cell proliferative and E6/E7-specific CD8+ T cell responses were significantly enhanced when mice were vaccinated subcutaneously (s.c.) or intramuscularly (i.m.) with TA-CIN formulated with GPI-0100. Vaccination was tested for therapy of mice bearing syngeneic HPV16 E6/E7+ tumors (TC-1) either in the lung or subcutaneously. Mice treated with TA-CIN/GPI-0100 vaccination exhibited robust E7-specific CD8+ T cell responses, which were associated with reduced tumor burden in the lung, whereas mice receiving either component alone were similar to controls. Since vaccination alone was not sufficient for cure, mice bearing s.c. TC-1 tumor were first treated with two doses of cisplatin and then vaccinated. Vaccination with TA-CIN/GPI-0100 i.m. substantially retarded tumor growth and extended survival after cisplatin therapy. Injection of TA-CIN alone, but not GPI-0100, into the tumor (i.t.) was similarly efficacious after cisplatin therapy, but the mice eventually succumbed. However, tumor regression and extended remission was observed in 80% of the mice treated with cisplatin and then intra-tumoral TA-CIN/GPI-0100 vaccination. These mice also exhibited robust E7-specific CD8+ T cell and HPV16 neutralizing antibody responses. Thus formulation of TA-CIN with GPI-0100 and intra-tumoral delivery after cisplatin treatment elicits potent therapeutic responses in a murine model of HPV16+ cancer.
We have previously created a potent DNA vaccine encoding calreticulin linked to the HPV oncogenic protein E7 (CRT/E7). While treatment of the CRT/E7 DNA vaccine generates significant tumor-specific immune responses in vaccinated mice, the potency of the DNA vaccine could potentially be improved by co-administration of a histone deacetylase inhibitor (HDACi) as HDACi have been shown to increase the expression of MHC class I and II molecules. Thus, we aimed to determine whether co-administration of a novel HDACi, AR-42, with therapeutic HPV DNA vaccines could improve activation of HPV antigen-specific CD8+ T cells resulting in potent therapeutic antitumor effects. To do so, HPV-16 E7-expressing murine TC-1 tumor-bearing mice were treated orally with AR-42 and/or CRT/E7 DNA vaccine via gene gun. Mice were monitored for E7-specific CD8+ T cell immune responses and antitumor effects. TC-1 tumor-bearing mice treated with AR-42 and CRT/E7 DNA vaccine experienced longer survival, decreased tumor growth, and enhanced E7-specific immune response compared to mice treated with AR-42 or CRT/E7 DNA vaccine alone. Additionally, treatment of TC-1 cells with AR-42 increased surface expression of MHC class I molecules and increased the susceptibility of tumor cells to the cytotoxicity of E7-specific T cells. This study indicates the ability of AR-42 to significantly enhance the potency of the CRT/E7 DNA vaccine by improving tumor-specific immune responses and antitumor effects. Both AR-42 and CRT/E7 DNA vaccine have been used in independent clinical trials and the current study serves as foundation for future clinical trials combining both treatments in cervical cancer therapy.
Cancer vaccine; human papillomavirus; cervical cancer; histone deacetylase inhibitor
A cornerstone of preclinical cancer research has been the use of clonal cell lines. However, this resource has underperformed in its ability to effectively identify novel therapeutics and evaluate the heterogeneity in a patient's tumor. The patient-derived xenograft (PDX) model retains the heterogeneity of patient tumors, allowing a means to not only examine efficacy of a therapy, but also basic tenets of cancer biology in response to treatment. Herein we describe the development and characterization of an ovarian-PDX model in order to study the development of chemoresistance. We demonstrate that PDX tumors are not simply composed of tumor-initiating cells, but recapitulate the original tumor's heterogeneity, oncogene expression profiles, and clinical response to chemotherapy. Combined carboplatin/paclitaxel treatment of PDX tumors enriches the cancer stem cell populations, but persistent tumors are not entirely composed of these populations. RNA-Seq analysis of six pair of treated PDX tumors compared to untreated tumors demonstrates a consistently contrasting genetic profile after therapy, suggesting similar, but few, pathways are mediating chemoresistance. Pathways and genes identified by this methodology represent novel approaches to targeting the chemoresistant population in ovarian cancer
Ovarian Cancer; Patient-derived xenograft; cancer stem cells; chemoresistance; animal models of cancer
Despite theconventional treatments of radiation therapy and chemotherapy, the five-year survival rates for patients withadvanced stage cervical cancers remain low. Cancer immunotherapy has emerged as an alternative, innovative therapythat may improve survival. Here we utilize a preclinical HPV-16 E6/E7-expressing tumor model, TC-1,and employ the chemotherapeutic agent cisplatin to generate an accumulation of CD11c+ dendritic cells in tumor loci making it an ideal location for the administration of therapeutic vaccines. Following cisplatin treatment, we tested different routes of administration of a therapeutic HPV vaccinia vaccine encoding HPV-16 E7 antigen (CRT/E7-VV).We found that TC-1tumor-bearing C57BL/6 mice treated with cisplatin and intratumoral injection of CRT/E7-VV significantly increased E7-specific CD8+ T cells in the blood and generated potent local and systemic antitumor immune responsescompared to mice receiving cisplatin and CRT/E7-VV intraperitoneally or mice treated with cisplatin alone. We further extended our study using a clinical grade recombinant vaccinia vaccine encoding HPV-16/18 E6/E7 antigens (TA-HPV).We found that intratumoral injection with TA-HPV following cisplatin treatment also led to increased E7-specific CD8+ T cells in the blood as well as significantly decreased tumor size compared to intratumoral injection with wild type vaccinia virus. Our study has strong implications for future clinical translation using intratumoralinjection of TA-HPV in conjunction with the current treatment strategies for patients with advanced cervical cancer.
cisplatin; vaccine; vaccinia virus; human papillomavirus; TA-HPV
Multiple classes of pharmacologic agents have the potential to induce the expression and release of pro-inflammatory factors from dying tumor cells. As a result, these cells can in theory elicit an immune response through various defined mechanisms to permanently eradicate disseminated cancer. However, the impact of chemotherapy on the tumor-specific immune response in the context of the tumor microenvironment is largely unknown. Within the tumor microenvironment, the immune response promoted by chemotherapy is antagonized by an immune-suppressive milieu, and the balance of these opposing forces dictates the clinical course of disease. Here we report that high antigen exposure within the tumor microenvironment following chemotherapy is sufficient to skew this balance in favor of a productive immune response. In elevating antigen exposure, chemotherapy can achieve long-term control of tumor progression without the need of an additional adjuvant. We found that chemotherapy initiated this phenomenon in the tumor microenvironment through an accumulation of dendritic cells, which stimulated CD8+ T cells and the type-I interferon pathway. From this conceptual base, we developed a simple approach to cancer therapy combining chemotherapy and vaccination that may be widely applicable.
Chemotherapy; tumor microenvironment; cisplatin; vaccination
The cellular development of resistance to chemotherapy contributes to the high mortality noted in patients affected by ovarian cancer. Novel compounds that specifically target cellular drug resistance in ovarian cancer are therefore highly desired. Previous epidemiological studies indicate that consumption of green tea and cruciferous vegetables is inversely associated with occurrence of ovarian cancer. Therefore revealing the effects and mechanisms of major components of green tea (epigallocatechin gallate, EGCG) and cruciferous vegetables (sulforaphane, SFN) on ovarian cancer cells will provide necessary knowledge for developing potential novel treatments for the disease. In this study, EGCG or SFN was used to treat both paclitaxel-sensitive (SKOV3-ip1) and -resistant (SKOV3TR-ip2) ovarian cancer cell lines alone or in combination. We found that SFN inhibits cell viability of both ovarian cancer cell lines time- and dose-dependently and that EGCG potentiates the inhibiting effect of SFN on ovarian cancer cells. Cell cycle analysis indicates SFN can arrest ovarian cancer cells in G2/M phase, while EGCG and SFN co-treatment can arrest cells in both G2/M and S phase. Combined EGCG and SFN treatment increases apoptosis significantly in paclitaxel-resistant SKOV3TR-ip2 cells after 6 days of treatment, while reducing the expression of hTERT, the main regulatory subunit of telomerase. Western blotting also indicates that SFN can down-regulate Bcl-2 (a gene involved in anti-apoptosis) protein levels in both cell types. Cleaved poly(ADP-ribose) polymerase (PARP) becomes up-regulated by 6 days of treatment with SFN and this is more pronounced for combination treatment indicating induction of apoptosis. Furthermore, phosphorylated H2AX is up-regulated after 6 days of treatment with SFN alone, and EGCG can potentiate this effect, suggesting that DNA damage is a potential cellular mechanism contributing to the inhibiting effect of EGCG and SFN combination treatment. Taken together, these results indicate that EGCG and SFN combination treatment can induce apoptosis by down-regulating of hTERT and Bcl-2 and promote DNA damage response specifically in paclitaxel-resistant ovarian cancer cell lines and suggest the use of these compounds for overcoming paclitaxel resistance in ovarian cancer treatment.
ovarian cancer; SKOV3; epigallocatechin gallate; sulforaphane; paclitaxel
Human papillomavirus (HPV) infections are particularly problematic for HIV + and solid organ transplant patients with compromised CD4+ T cell-dependent immunity as they produce more severe and progressive disease compared to healthy individuals. There are no specific treatments for chronic HPV infection, resulting in an urgent unmet need for a modality that is safe and effective for both immunocompromised and otherwise normal patients with recalcitrant disease. DNA vaccination is attractive because it avoids the risks of administration of live vectors to immunocompromised patients, and can induce potent HPV-specific cytotoxic T cell responses. We have developed a DNA vaccine (pNGVL4a-hCRTE6E7L2) encoding calreticulin (CRT) fused to E6, E7 and L2 proteins of HPV-16, the genotype associated with approximately 90% vaginal, vulvar, anal, penile and oropharyngeal HPV-associated cancers and the majority of cervical cancers. Administration of the DNA vaccine by intramuscular (IM) injection followed by electroporation induced significantly greater HPV-specific immune responses compared to IM injection alone or mixed with alum. Furthermore, pNGVL4a-hCRTE6E7L2 DNA vaccination via electroporation of mice carrying an intravaginal HPV-16 E6/E7-expressing syngeneic tumor demonstrated more potent therapeutic effects than IM vaccination alone. Of note, administration of the DNA vaccine by IM injection followed by electroporation elicited potent E6 and E7-specific CD8+ T cell responses and antitumor effects despite CD4+ T cell-depletion, although no antibody response was detected. While CD4+ T cell-depletion did reduce the E6 and E7-specific CD8+ T cell response, it remained sufficient to prevent subcutaneous tumor growth and to eliminate circulating tumor cells in a model of metastatic HPV-16+ cancer. Thus, the antibody response was CD4-dependent, whereas CD4+ T cell help enhanced the E6/E7-specific CD8+ T cell immunity, but was not required. Taken together, our data suggest that pNGVL4a-hCRTE6E7L2 DNA vaccination via electroporation warrants testing in otherwise healthy patients and those with compromised CD4+ T cell immunity to treat HPV-16-associated anogenital disease and cancer.
DNA vaccine; Human papillomavirus; Immunosuppression; CD4 depletion; Calreticulin; Immunotherapy
Persistence of Human Papillomavirus (HPV) infection is necessary for the development of cervical cancer. Additionally, infection with HPV is implicated in the majority of cases of other genital tract malignancies including vulvar, penile, and vaginal cancer. HPV testing and vaccination are a routine part of OB/GYN clinical practice. With an enhanced public awareness of HPV infections, many patients turn to their OB/GYN with questions about transmission, testing and prevention. In this review, we will discuss the biology of HPV, epidemiology of disease, methods and indications for testing, and vaccination strategies.
Cervical cancer screening; HPV biology; HPV testing; HPV vaccination; Human Papillomavirus
Topotecan at a dose of 1.5 mg/m2 on days 1 to 5 of a 21-day cycle is an approved therapy for recurrent ovarian cancer. However, heavily pretreated patients may be predisposed to hematologic adverse events. This prospective study, therefore, investigates the safety and efficacy of an alternate weekly schedule of topotecan in patients with recurrent ovarian or peritoneal cancer.
Patients with potentially platinum-sensitive recurrent ovarian or peritoneal cancer were treated with 4.0 mg/m2 weekly topotecan as tolerated until disease progression. Antitumor response and safety were assessed. Dose reductions, delays, or omissions were implemented for grades 3–4 adverse events.
Of the 41 enrolled patients (median age, 62 years; range, 42 to 82 years), 39 patients had ovarian cancer, and 2 patients had peritoneal cancer. The median platinum-free interval was 11.7 months. A median of 9 topotecan cycles (range, 1 to 45 doses) was administered. Weekly topotecan was well tolerated: 7 (17%) patients had grades 3–4 neutropenia, and 9 (22%) had grades 3–4 fatigue. No grade 4 thrombocytopenia or anemia was reported. Of 38 response-evaluable patients, 1 (3%) had a complete response, 8 (21%) had a partial response, 16 (42%) had stable disease, and 13 (34%) had progressive disease.
Weekly topotecan was well tolerated in patients with platinum-sensitive ovarian or peritoneal cancer at first relapse, with a hematologic profile that compared favorably with that of the 5-day topotecan regimen. Moreover, antitumor activity was similar to that reported for the 5-day regimen.
Chemotherapy; Platinum-sensitive ovarian cancer; Relapsed ovarian cancer; Topotecan; Weekly topotecan
Identification of human papillomavirus (HPV) as the etiologic factor of cervical, anogenital, and a subset of head and neck cancers has stimulated the development of preventive and therapeutic HPV vaccines to control HPV-associated malignancies. Excitement has been generated by the commercialization of two preventive L1-based vaccines, which use HPV virus-like particles (VLPs) to generate capsid-specific neutralizing antibodies. However, factors such as high cost and requirement for cold chain have prevented widespread implementation where they are needed most.
Next generation preventive HPV vaccine candidates have focused on cost-effective stable alternatives and generating broader protection via targeting multivalent L1 VLPs, L2 capsid protein, and chimeric L1/L2 VLPs. Therapeutic HPV vaccine candidates have focused on enhancing T cell-mediated killing of HPV-transformed tumor cells, which constitutively express HPV-encoded proteins, E6 and E7. Several therapeutic HPV vaccines are in clinical trials.
Although progress is being made, cost remains an issue inhibiting the use of preventive HPV vaccines in countries that carry the majority of the cervical cancer burden. In addition, progression of therapeutic HPV vaccines through clinical trials may require combination strategies employing different therapeutic modalities. As research in the development of HPV vaccines continues, we may generate effective strategies to control HPV-associated malignancies.
clinical trials; human papillomavirus; immunotherapy; vaccines
The hedgehog (HH) pathway has been implicated in the formation and maintenance of a variety of malignancies, including ovarian cancer; however, it is unknown whether HH signaling is involved in ovarian cancer chemoresistance. The goal of this study was to determine the effects of antagonizing the HH receptor, Smoothened (Smo), on chemotherapy response in ovarian cancer. Expression of HH pathway members was assessed in 3 pairs of parental and chemotherapy-resistant ovarian cancer cell lines (A2780ip2/A2780cp20, SKOV3ip1/SKOV3TRip2, HeyA8/HeyA8MDR) using qPCR and Western blot. Cell lines were exposed to increasing concentrations of two different Smo antagonists (cyclopamine, LDE225) alone and in combination with carboplatin or paclitaxel. Selective knockdown of Smo, Gli1 or Gli2 was achieved using siRNA constructs. Cell viability was assessed by MTT assay. A2780cp20 and SKOV3TRip2 orthotopic xenografts were treated with vehicle, LDE225, paclitaxel or combination therapy. Chemoresistant cell lines demonstrated higher expression (>2-fold, p<0.05) of HH signaling components compared to their respective parental lines. Smo antagonists sensitized chemotherapy-resistant cell lines to paclitaxel, but not to carboplatin. LDE225 treatment also increased sensitivity of ALDH-positive cells to paclitaxel. A2780cp20 and SKOV3TRip2 xenografts treated with combined LDE225 and paclitaxel had significantly less tumor burden than those treated with vehicle or either agent alone. Increased taxane sensitivity appeared to be mediated by a decrease in P-glycoprotein (MDR1) expression. Selective knockdown of Smo, Gli1 or Gli2 all increased taxane sensitivity. Smo antagonists reverse taxane resistance in chemoresistant ovarian cancer models, suggesting combined anti-HH and chemotherapies could provide a useful therapeutic strategy for ovarian cancer.
Smoothened; LDE225; paclitaxel; chemotherapy resistance; ovarian cancer
To estimate the frequency of mismatch repair deficiencies associated with hereditary nonpolyposis colorectal cancer, or Lynch syndrome, in women less than age 50 with endometrial cancer.
Consecutive patients less than age 50 diagnosed with endometrial adenocarcinoma were identified. Available pathologic specimens were freshly sliced, and protein expression for MLH1, MSH2, MSH6, and PMS2 was evaluated by immunohistochemistry. Slides were scored on a semiquantitative method with complete absence of any of the four proteins suggesting a deficiency. All results were confirmed by microsatellite instability testing.
Sixty-one pathology specimens were analyzed. Twenty-one (34%) of the tumors had absence of staining of at least one of the four mismatch repair proteins determined by immunohistochemistry and confirmed by microsatellite instability testing. Obese patients were less likely than nonobese patients to have a mismatch repair deficiency (21% versus 59%, respectively). Non-obese patients had a relative risk for a mismatch repair deficiency of 5.5 (95% confidence interval 1.6–19.1; P=.01).
Many women diagnosed with endometrial cancer before age 50 will have a mismatch repair deficiency discovered by immunohistochemistry and microsatellite instability testing. A number of young women diagnosed with endometrial cancer will require further genetic testing for mismatch repair mutations.
Advanced-stage ovarian cancer is characterized by high mortality due to development of resistance to conventional chemotherapy. Novel compounds that can enhance the efficacy of conventional chemotherapy in ovarian cancer may overcome this drug resistance. Consumption of green tea (epigallocatechin gallate, EGCG) and cruciferous vegetables (sulforaphane, SFN) is inversely associated with occurrence of ovarian cancer and has anticancer effects through targeting multiple molecules in cancer cells. However, the effects of EGCG and SFN combinational treatment on ovarian cancer cells and on efficacy of cisplatin to these cells are unknown. In this study, EGCG or SFN was used to treat both cisplatin-sensitive (A2780) and cisplatin-resistant (A2780/CP20) ovarian cancer cells alone or in combination with cisplatin. We found that EGCG and SFN combinational treatment can reduce cell viability of both ovarian cancer cell lines time- and dose-dependently. Furthermore, EGCG and SFN combinational treatment can enhance cisplatin-induced apoptosis and G2/M phase arrest, thereby enhancing the efficacy of cisplatin on both cisplatin-sensitive and cisplatin-resistant ovarian cancer cells. EGCG and SFN combinational treatment upregulated p21 expression induced by cisplatin in cisplatin-sensitive ovarian cancer cells, while p27 expression was not regulated by these treatments. Collectively, these studies provide novel approaches to overcoming cisplatin chemotherapy resistance in ovarian cancer.
Within heterogeneous tumors, subpopulations often labeled cancer stem cells (CSCs) have been identified that have enhanced tumorigenicity and chemoresistance in ex vivo models. However, whether these populations are more capable of surviving chemotherapy in de novo tumors is unknown.
We examined 45 matched primary/recurrent tumor pairs of high grade ovarian adenocarcinomas for expression of CSC markers ALDH1A1, CD44 and CD133 using immunohistochemistry. Tumors collected immediately after completion of primary therapy were then laser-capture microdissected and subjected to a quantitative PCR array examining stem cell biology pathways (Hedgehog, Notch, TGF-β and Wnt). Select genes of interest were validated as important targets using siRNA-mediated downregulation.
Primary samples were composed of low densities of ALDH1A1, CD44 and CD133. Tumors collected immediately after primary therapy were more densely composed of each marker, while samples collected at first recurrence, before initiating secondary therapy, were composed of similar percentages of each marker as their primary tumor. In tumors collected from recurrent platinum-resistant patients, only CD133 was significantly increased. Of stem cell pathway members examined, 14% were significantly overexpressed in recurrent compared to matched primary tumors. Knockdown of genes of interest, including endoglin/CD105 and the hedgehog mediators Gli1 and Gli2, led to decreased ovarian cancer cell viability, with Gli2 demonstrating a novel contribution to cisplatin resistance.
These data indicate that ovarian tumors are enriched with CSCs and stem cell pathway mediators, especially at the completion of primary therapy. This suggests that stem cell subpopulations contribute to tumor chemoresistance and ultimately recurrent disease.
CD133; CD44; aldehyde dehydrogenase; ALDH1A1; endoglin; CD105; gli1; gli2; cancer stem cell; ovarian cancer
Identification of associations between global DNA methylation and excess body weight (EBW) and related diseases and their modifying factors are an unmet research need that may lead to decreasing DNA methylation-associated disease risks in humans. The purpose of the current study was to evaluate the following; 1) Association between the degree of peripheral blood mononuclear cell (PBMC) L1 methylation and folate, and indicators of EBW, 2) Association between the degree of PBMC L1 methylation and folate, and insulin resistance (IR) as indicated by a higher homeostasis model assessment (HOMA-IR).
The study population consisted of 470 child-bearing age women diagnosed with abnormal pap. The degree of PBMC L1 methylation was assessed by pyrosequencing. Logistic regression models specified indicators of EBW (body mass index–BMI, body fat–BF and waist circumference–WC) or HOMA-IR as dependent variables and the degree of PBMC L1 methylation and circulating concentrations of folate as the independent predictor of primary interest.
Women with a lower degree of PBMC L1 methylation and lower plasma folate concentrations were significantly more likely to have higher BMI, % BF or WC (OR = 2.49, 95% CI:1.41–4.47, P = 0.002; OR = 2.49, 95% CI:1.40–4.51, P = 0.002 and OR = 1.98, 95% = 1.14–3.48 P = 0.0145, respectively) and higher HOMA-IR (OR = 1.78, 95% CI:1.02–3.13, P = 0.041).
Our results demonstrated that a lower degree of PBMC L1 methylation is associated with excess body weight and higher HOMA-IR, especially in the presence of lower concentrations of plasma folate.
Jagged1, a Notch ligand, is expressed on both tumor epithelial and endothelial cells, and therefore may be amenable to dual targeting of the tumor stroma and malignant cell compartments of the tumor microenvironment.
We describe in vitro effects of targeting of Jagged1 on ovarian cancer cells and in vivo effects of independent targeting of stromal and malignant cell Jagged1 using species-specific human or murine siRNA constructs incorporated into chitosan nanoparticles (CH) and delivered intravenously in an orthotopic mouse model.
Jagged1 expression was prominent in SKOV3ip1, and IGROV-AF1, and significantly overexpressed in SKOV3TRip2, a taxane-resistant SKOV3 subclone. Jagged1 silencing with siRNA decreased cell viability and reversed taxane chemoresistance. In two different orthotopic ovarian cancer models, treatment with anti-human Jagged1 siRNA-CH reduced growth by 54.4-58.3%, and with anti-murine Jagged1 siRNA-CH reduced growth by 41.7-48.8%. The combination of both species-specific constructs reduced tumor weight by 87.5-93.1% and sensitized SKOV3TRip2 tumors to docetaxel in vivo. Tumors demonstrated reduced microvessel density with anti-murine Jagged1 constructs, and decreased proliferation with anti-human Jagged1 siRNAs-CH. In addition, we show that Jagged1 downregulation does not sensitize cells to taxanes through a reduction in MDR1 expression, but at least in part by crosstalk with the GLI2 mediator of the Hedgehog pathway.
Jagged1 plays dual roles in cancer progression, through an angiogenic function in tumor endothelial cells, and through proliferation and chemoresistance in tumor cells. Dual inhibition represents an attractive therapeutic strategy for ovarian and potentially other malignancies.
Jagged1; chemoresistance; small interfering RNA; ovarian cancer
The objective of the study was to evaluate LINE-1 methylation as an intermediate biomarker for the effect of folate and vitamin B12 on the occurrence of higher grades of cervical intraepithelial neoplasia (CIN 2+).
Study included 376 women who tested positive for HR-HPVs and were diagnosed with CIN 2+ (cases) or ≤ CIN 1 (non-cases). CIN 2+ (yes/no) was the dependent variable in logistic regression models that specified the degree of LINE-1 methylation of peripheral blood mononuclear cells (PBMCs) and of exfoliated cervical cells (CCs) as the independent predictors of primary interest. In analyses restricted to non-cases, PBMC LINE-1 methylation (≥70% vs. <70%) and CC LINE-1 methylation (≥54% vs. <54%) were the dependent variables in logistic regression models that specified the circulating concentrations of folate and vitamin B12 as the primary independent predictors.
Women in the highest tertile of PBMC LINE-1 methylation had 56% lower odds of being diagnosed with CIN 2+ (OR = 0.44; 95% CI, 0.24-0.83; P = 0.011) while there was no significant association between degree of CC LINE-1 methylation and CIN 2+ (OR = 0.86; 95% CI, 0.51-1.46; P = 0.578). Among non-cases, women with supra-physiologic concentrations of folate (>19.8 ng/mL) and sufficient concentrations of plasma vitamin B12 (≥ 200.6 ng/mL) were significantly more likely to have highly methylated PBMCs compared to women with lower folate and lower vitamin B12 (OR = 3.92; 95% CI, 1.06-14.52; P = 0.041). None of the variables including folate and vitamin B12 were significantly associated with CC LINE-1 methylation.
These results suggest that a higher degree of LINE-1 methylation in peripheral blood mononuclear cells, a one-carbon nutrient related epigenetic alteration, is associated with a lower risk of developing cervical intraepithelial neoplasia.
methylation; cervical; neoplasia
Even though HPV 16 is the most common HPV genotype associated with cancerous lesions of the cervix, only a fraction of HPV 16 infected women are diagnosed with pre-cancerous lesions of the cervix. Therefore, molecular changes in HPV 16 rather than infections per se may serve as better screening or diagnostic biomarkers. The purpose of the study was to evaluate whether methylation status of specific regions of the HPV E6 gene promoter and enhancer is independently associated with the likelihood of being diagnosed with higher grades of cervical intraepithelial neoplasia (CIN 2+).
The study included 75 HPV 16 positive women diagnosed with CIN 2+ or ≤ CIN 1. Pyrosequencing technology was applied to quantify methylation at 6 cytosine guanine dinucleotide (CpG) sites of the HPV 16 E6 promoter and enhancer. CIN 2+ (yes/no) was the dependent variable in logistic regression models that specified the degree of methylation of the CpG sites of the HPV 16 E6 gene as the primary independent predictors. All models were adjusted for demographic, lifestyle, known risk factors for cervical cancer and circulating concentrations of “cancer-protective” micronutrients.
The odds of being diagnosed with CIN 2+ was 79% lower when the degree of methylation of the HPV 16 enhancer and promoter sites were ≥9.5% (OR= 0.21; 95% CI, 0.06–0.79; P=0.02).
Results suggested that CpG methylation is independently involved in the biology of HPV-16 as well as in the development of higher grades of CIN.
HPV 16; methylation; cervical; neoplasia
► The hook effect occurs with extremely high levels of hCG, saturating detection antibodies, leading to falsely low laboratory results. ► In the literature, descriptions of the hook effect are rare in cases of gestational trophoblastic diseases. ► If unrecognized, this can lead to delayed therapy or mismanagement of care.
Hook effect; Molar pregnancy; Falsely low hCG
More than 99% of cervical cancers have been associated with human papillomaviruses (HPVs), particularly HPV type 16. The clear association between HPV infection and cervical cancer indicates that HPV serves as an ideal target for development of preventive and therapeutic vaccines. Although the recently licensed preventive HPV vaccine, Gardasil, has been shown to be safe and capable of generating significant protection against specific HPV types, it does not have therapeutic effect against established HPV infections and HPV-associated lesions. Two HPV oncogenic proteins, E6 and E7, are consistently co-expressed in HPV-expressing cervical cancers and are important in the induction and maintenance of cellular transformation. Therefore, immunotherapy targeting E6 and/or E7 proteins may provide an opportunity to prevent and treat HPV-associated cervical malignancies. It has been established that T cell-mediated immunity is one of the most crucial components to defend against HPV infections and HPV-associated lesions. Therefore, effective therapeutic HPV vaccines should generate strong E6/E7-specific T cell-mediated immune responses. DNA vaccines have emerged as an attractive approach for antigen-specific T cell-mediated immunotherapy to combat cancers. Intradermal administration of DNA vaccines via a gene gun represents an efficient way to deliver DNA vaccines into professional antigen-presenting cells in vivo. Professional antigen-presenting cells, such as dendritic cells, are the most effective cells for priming antigen-specific T cells. Using the gene gun delivery system, we tested several DNA vaccines that employ intracellular targeting strategies for enhancing MHC class I and class II presentation of encoded model antigen HPV-16 E7. Furthermore, we have developed a strategy to prolong the life of DCs to enhance DNA vaccine potency. More recently, we have developed a strategy to generate antigen-specific CD4+ T cell immune responses to further enhance DNA vaccine potency. The impressive preclinical data generated from our studies have led to several HPV DNA vaccine clinical trials.
antigen presenting cells; dendritic cells; human papillomavirus type 16; oncogene protein E7; papillomavirus vaccines; vaccination; vaccines; DNA
Because the combination of multiple modalities for cancer treatment is more likely to generate more potent therapeutic effects for the control of cancer, we have explored the combination of chemotherapy using cisplatin, which is routinely used in chemotherapy for advanced cervical cancer, with immunotherapy using DNA vaccines encoding calreticulin (CRT) linked to human papillomavirus type 16 E7 antigen (CRT/E7) in a preclinical model.
We characterized the combination of cisplatin with CRT/E7 DNA vaccine using different regimen for its potential ability to generate E7-specific CD8+ T-cell immune responses as well as antitumor effects against E7-expressing tumors.
Our results indicate that treatment of tumor-bearing mice with chemoimmunotherapy combining cisplatin followed by CRT/E7 DNA generated the highest E7-specific CD8+ T-cell immune response and produced the greatest antitumor effects and long-term survival as well as significant levels of E7-specific tumor-infiltrating lymphocytes compared with all the other treatment regimens. Furthermore, we found that treatment with cisplatin leads to the cell-mediated lysis of E7-expressing tumor cells in vitro and increased number of E7-specific CD8+ T-cell precursors in tumor-bearing mice. In addition, we observed that E7-specific CD8+ T-cells migrate to and proliferate in the location of TC-1 tumors in mice treated with cisplatin.
Thus, our data suggest that chemoimmunotherapy using cisplatin followed by CRT/E7 DNA vaccine is an effective treatment against E7-expressing tumors and may potentially be translated into the clinical arena.