Pancreatic cancer is one of the most serious types of cancer, with a five-year survival rate at only 6%. There is a critical need to develop more effective treatments for pancreatic cancer. Growing evidence shows that chronic inflammation plays a crucial role in tumor initiation and progression. Here we demonstrated that the endogenous expression of the inflammatory cytokine interleukin-6 (IL-6) correlates with signal transducer and activator of transcription 3 (STAT3) phosphorylation in human pancreatic cancer cells. Inhibition of the endogenous IL-6/STAT3 pathway reduces cell viability. Exogenous IL-6 induces STAT3 phosphorylation, but differently induces phosphorylation of STAT3 upstream kinases, Janus kinase 1(JAK1), JAK2, and tyrosine kinase 2 (TYK2). Interestingly, LLL12, a nonpeptide, cell-permeable small molecule, selectively blocked exogenous IL-6-induced STAT3 phosphorylation and nuclear translocation in both PANC-1 and ASPC-1 pancreatic cancer cell lines independently of the phosphorylation of JAK1, JAK2, and TYK2. These results suggest that the inhibition of endogenous and exogenous IL-6-mediated STAT3 signaling may be a potential therapeutic approach for pancreatic cancer.
Interleukin-6; signal transducer and activator of transcription 3; pancreatic cancer
Dichamanetin is a C-benzylated flavanone isolated as a major secondary metabolite from Piper sarmentosum, a plant used as a spice in Southeast Asia. This studied aimed to understand the path through which dichamanetin exerts it antiproliferative effect.
Materials and Methods
The study of several signaling cellular components, namely, reactive oxygen species (ROS) levels, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) transcription factor, mitochondrial membrane potential, DNA binding, poly ADP-ribose polymerase (PARP1) inhibition and proteasome inhibition was performed using enzyme-linked immunosorbent (ELISA) assay, cell sorting, and western blot.
Dichamanetin significantly reduced the cell viability of various types of human cancer cells (HT-29 colon, DU145 prostate, and MDA-MB-231 breast cancer) in a dose- and time-dependent manner and induced G1 arrest of the cell cycle. It was also demonstrated that the selective cytotoxic effect of dichamanetin in cancer cells is mediated by the induction of oxidative stress.
Our findings suggest that dichamanetin from an edible herb has cancer chemotherapeutic potential.
Piperaceae; Piper sarmentosum; Dichamanetin; cytotoxicity; NF-κB inhibition; DNA binding; mitochondrial membrane potential; PARP-1; ROS
Although 5-fluorouracil (5-FU)-based combination chemotherapy (i.e. FOLFIRINOX) has demonstrated effectiveness against pancreatic cancer, novel therapeutic strategies must be developed to increase the therapeutic window of these cytotoxic agents. Genistein is a soy-derived isoflavone with pleiotropic biologic effects that can enhance the antitumor effect of chemotherapeutic agents.
To understand how genistein potentiates the antitumor effects of 5-FU, we examined apoptosis and autophagy in MIA PaCa-2 human pancreatic cancer cells or their derived xenografts. Apoptosis was evaluated using DNA fragmentation assays and Western blots of poly (ADP ribose) polymerase and caspase-3. Meanwhile, autophagy was evaluated using Western blots of microtubule-associated protein light chain 3 (LC3)-I/II, fluorescent microscopy observation of green fluorescent protein-LC3B puncta formation, and acidic vesicular organelle formation using acridine orange staining. Tumors from animal treatment studies were examined for apoptosis and autophagy using the TUNEL assay and immunohistochemical staining of LC3B, respectively.
We observed that genistein increased 5-FU-induced cell death through increased apoptosis as well as autophagy. The increased apoptosis and autophagy was accompanied by decreased B-cell lymphoma 2 (bcl-2) and increased beclin-1 protein levels, respectively. Animal treatment studies supported these observations. The combination of 5-FU and genistein significantly decreased final xenograft tumor volume when compared to 5-FU alone by inducing apoptosis as well as autophagy.
Genistein can potentiate the antitumor effect of 5-FU by inducing apoptotic as well as autophagic cell death. These results demonstrate the potential of genistein as an adjuvant therapeutic agent against pancreatic cancer.
Pancreatic ductal adenocarcinoma; Apoptosis; Autophagy; Cell death; Genistein; 5-Fluorouracil
Soluble epoxide hydrolase (sEH) hydrolyses/inactivates anti-inflammatory epoxyeicosatrienoic acids (EETs) to their corresponding diols, and targeting sEH leads to strong anti-inflammatory effects. In the present study, using a tissue microarray and immunohistochemical approach, a significant increase of sEH expression was identified in ulcerative colitis (UC)-associated dysplasia and adenocarcinoma. The effects of deficiency in the sEH gene were determined on dextran sulfate sodium (DSS) colitis-induced carcinogenesis. The effects of EETs on lipopolysaccharide (LPS)-activated macrophages were analyzed in vitro. With extensive histopathological and immunohistochemical analyses, compared to wild-type mice, sEH−/− mice exhibited a significant decrease in tumor incidence (13/20 vs. 6/19, p<0.05) and a markedly reduced average tumor size (59.62±20.91 mm3 vs. 22.42±11.22 mm3), and a significant number of pre-cancerous dysplasia (3±1.18 vs. 2±0.83, p<0.01). The inflammatory activity, as measured by the extent/proportion of erosion/ulceration/dense lymphoplasmacytosis (called active colitis index) in the colon, was significantly lower in sEH−/− mice (44.7%±24.9% vs. 20.2%±16.2%, p<0.01). The quantitative polymerase chain reaction (qPCR) assays demonstrated significantly low levels of cytokines/chemokines including monocyte chemoattractant protein (MCP-1), inducible nitric oxide synthase (iNOS), vasopressin-activated calcium-mobilizing (VCAM-1), interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α). In vitro, LPS-activated macrophages treated with 14,15-EET showed a significant reduction of LPS-triggered IL-1β and TNF-α expression. Eicosanoic acid metabolic profiling revealed a significant increase of the ratios of EETs/dihydroeicosatrienoic acids (DHETs) and epoxyoctadecennoic acid/dihydroxyoctadecenoic acid (EpOMEs/DiHOMEs). These results indicate that sEH plays an important role in the development of colitis and in inducing carcinogenesis.
Soluble epoxide hydrolase; dextran sulfate sodium; colitis; carcinogenesis; mice
Invasive urothelial carcinoma of the bladder (UCB) is characterized by alterations in cell-cycle regulatory pathways. Defects in the expression of cyclin D1, a key cell-cycle regulator, have been implicated in progression of various types of cancer. In the present study, we investigated whether cyclin D1 expression is associated with clinicopathological parameters and whether it has any potential prognostic value in determining risk of UCB recurrence.
Patients and Methods
Tissue microarrays containing bladder cancer specimens (n=212) and adjacent normal bladder tissues (n=131) were immunostained using an antibody against cyclin D1. The association between cyclin D1 and clinicopathological parameters including stage, lymph node metastasis, and disease-free survival, were evaluated. Cyclin D1 mRNA expression data from human normal bladder (n=14) and cancer specimens (n=28) were extracted from the public Oncomine database.
Cyclin D1 mRNA and protein expression were significantly higher in UCB compared to adjacent non-malignant bladder tissue (for mRNA p=0.003, for protein p=0.001). Cyclin D1 protein expression was significantly higher in non-invasive tumors than in muscle-invasive UCB (p=0.016). Among patients with muscle-invasive UCB, increased cyclin D1 expression in tumor cells significantly correlated with lymph node metastasis (p<0.001), and there was a trend of cyclin D1 together with lymph node positivity to be associated with disease recurrence (p=0.678). Loss of nuclear cyclin D1 expression in tumor cells was likewise significantly associated with the presence of lymph node metastasis (p<0.001).
Altered expression of cyclin D1 is associated with lymph node metastasis and risk of UCB recurrence. Cyclin D1 expression may therefore have clinical value as a prognostic marker and potential therapeutic target.
Biomarker; bladder cancer; cyclin D1; muscle-invasive
Small cell lung cancer (SCLC) is the most aggressive form of lung cancer with poor disease outcome. Chemotherapeutic agent paclitaxel (PA) is commonly used as a second-line treatment in SCLC, but response rates are low.
Materials and Methods
86M1 SCLC cells were treated in the presence or absence of Paclitaxel and TRAIL or the combination for 24 hours. Western blot analysis was utilized to examine protein expression, cell surface protein expression and membrane integrity were elucidated by flow cytometry, and immunofluorescence microscopy was used to demonstrate translocation of proteins to the cell nucleus.
Human 86M1 SCLC cells were found to be resistant to PA killing in vitro. This resistance is mediated by up-regulation of pro-survival protein BCL-xl. However, PA also increases surface expression of death receptors 4 and 5 (DR4 and DR5, respectively). The death receptors’ ligand increased SCLC killing by PA through an apparent caspase-independent route involving activation/translocation of AIF.
The addition of TRAIL to PA can potentiate apoptosis in a relatively PA-resistant SCLC line (specifically 86M1 cells). More importantly, we are the first to report an active method of resistance to paclitaxel in SCLC via BCL-xl up-regulation.
The proliferation in human prostate carcinomas, PC3 and MDA-PCa-2b, was analyzed for cells treated with LLW-3-6 and celecoxib in the presence and absence of sulfasalazine. LLW-3-6 was more potent than celecoxib at mediating a dose-dependent reduction of viable PC3 cells. Co-treatment with a non-lethal dose of sulfasalazine diminished the potency of both drugs in this cell line. The effects of the drugs in MDA-PCa-2b cells were less significant than those observed in the PC3 cells. Localization of COX-2 in LLW-3-6- and CBX-treated PC3 cells is consistent with protein aggregation known for cells responding to stress stimuli. To complement this, an analysis of the theoretical binding interactions of LLW-3-6 was completed to illustrate the potential of LLW-3-6 to bind to COX-2 in a manner similar to that of celecoxib. Studies to further define the mechanism of action for LLW-3-6 are ongoing.
Benzimidazole; celecoxib; COX-2; sulfasalazine; PC3; MDA-PCa 2b; prostate cancer; docking; focal adhesion
Lung cancer is the second leading cause of mortality among men and women in the U.S. Among different varieties of lung cancer, the non-small cell lung cancer (NSCLC) has the highest frequency comprising about 85% of cases. We evaluated 1-methyl-4-phenylpyridinium ion (Mpp+) for cytotoxicity against human lung adenocarcinoma A549, human normal lung and rat normal liver cells after a 48-hour treatment.
Materials and Methods
In vitro cytotoxicity was evaluated by the crystal-violet method, mitochondrial respiratory sratus by calorimetric reduction of 3 -( 4 ,5-dimerhylthiazol-2-yl)-5-( 3-carboxymethoxyphenyl)-2 -( 4-sulfophenyl )-2H-tetrazolium, mitochondrial membrane potential by rhodamine 123 jluorometric assay and glutathione levels by 5,5-dithiobis-2-nitrobenzoic acid.
lvfpp+ caused a significant dose-dependent death of A549 cells. In human normal lung and rat normal liver cells, Mpp+ did not cause severe cytotoxicity, which was reflected with a selectivity index (Sf) of greater than 7. Further studies revealed that, in addition to irs interaction with mitochondria, Mpp+ significantly depleted total glutathione levels in A549 cells.
The results clearly indicate that Mpp+ possesses highly selective, potent anticancer activity against lung adenocarcinoma.
Anticancer activity; glutathione; human non-small cell lung adenocarcinoma cells; 1-methyl-4-phenylpyridinium ion; selectivity index
Cancer cells have an essential demand for vitamin B12 (cobalamin) to enable cellular replication. The present pilot study quantified the immunohistochemical expression of vitamin B12 transport protein (Transcobalamin II; TCII), cell surface receptor (Transcobalamin II-R; TCII-R) and proliferation protein (Ki-67) in human tumor xenografts.
Materials and Methods
Tissue microarray slides containing 34 xenograft tumor tissues were immunohistochemically stained using TCN2 (anti-TCII), CD320 (anti-TCII-R) and MIB-1 (anti-Ki-67) antibodies. Representatively stained areas of all slides were digitally imaged and protein expression was quantified using ImageJ software plugins.
All xenograft tumor tissues stained positively for TCII, TCII-R and Ki-67 proteins; expression varied both within and between tumor types. Correlation between TCII/TCII-R and Ki-67 expression was not significant in xenograft tissues.
Proliferating cancer cells express measurable levels of TCII and TCII-R. Immunohistochemical quantification of these markers may be useful as a tool for detection of tumors, tailored selection of anti-tumor therapies and surveillance for evidence of recurrent disease.
Vitamin B12; immunohistochemistry; transcobalamin II; transport protein; receptor; Ki-67; xenograft
Response Evaluation Criteria in Solid Tumors (RECIST) defined measurements are limited when evaluating soft tissue sarcoma (STS) response to therapy. Histopathologic assessment of STS response requires a determination of necrosis following resection. A novel semiautomated technique for volumetric measurement of tumor necrosis, using enhanced magnetic resonance imaging (CE-MRI), is described.
Patients and Methods
Eighteen patients with STS were treated with neoadjuvant therapy and then resected. CE-MRI, obtained prior to resection, were evaluated by two observers using semi-automated segmentation. Tumor volume and percent necrosis was compared with histology and RECIST measurements.
The median percent necrosis, determined histologically and from CE-MRI, was 71.9% and 67.8%, respectively. Accuracy of these semiautomated measurements was confirmed, being statistically similar to those obtained at histopathologic assessment of the resected tumor. High Intra-class correlation coefficients suggest good inter-observer reproducibility. Tumor necrosis did not correlate with RECIST measurements.
Semi-automated determination of tumor volume and necrosis, using CE-MRI, is suggested to be accurate and reproducible.
Sarcoma; necrosis; magnetic resonance imaging; segmentation
Because annulated indoles have almost no representation in the PubChem or MLSMR databases, an unprecedented class of an indole-based library was constructed, using the indole aryne methodology, and screened for antitumor activity. Sixty-six novel 6,7-annulated-4-substituted indole compounds were synthesized, using a strategic combination of 6,7-indolyne cycloaddition and cross-coupling reactions under both Suzuki-Miyaura and Buchwald-Hartwig conditions, and tested for their effectiveness against murine L1210 tumor cell proliferation in vitro.
Materials and Methods
Various markers of tumor cell metabolism, DNA degradation, mitotic disruption, cytokinesis and apoptosis were assayed in vitro to evaluate drug cytotoxicity.
Most compounds inhibited the metabolic activity of leukemic cells in a time- and concentration-dependent manner but only 9 of them were sufficiently potent to inhibit L1210 tumor cell proliferation by 50% in the low-μM range after 2 (IC50: 4.5–20.4 μM) and 4 days (0.5–4.0 μM) in culture. However, the antiproliferative compounds that were the most effective at day 4 were not necessarily the most potent at day 2, suggesting different speeds of action. A 3-h treatment with antiproliferative annulated indole was sufficient to inhibit, in a concentration-dependent manner, the rate of DNA synthesis measured in L1210 cells over a 0.5-h period of pulse-labeling with 3H-thymidine. Four of the antiproliferative compounds had weak DNA-binding activities but one compound reduced the fluorescence of the ethidium bromide-DNA complex by up to 53%, suggesting that some annulated indoles might directly interact with double-stranded DNA to disrupt its integrity and prevent the dye from intercalating into DNA base pairs. However, all 9 antiproliferative compounds induced DNA cleavage at 24 h in L1210 cells, containing 3H-thymidine-prelabeled DNA, suggesting that these antitumor annulated indoles might trigger an apoptotic pathway of DNA fragmentation. Indeed the antiproliferative annulated indoles caused a time-dependent increase of caspase-3 activity with a peak at 6 h. Interestingly, the compounds with the most potent antiproliferative IC50 values at day 2 were consistently the most effective at inhibiting DNA synthesis at 3 h and inducing DNA fragmentation at 24 h. After 24–48 h, antiproliferative concentrations of annulated indoles increased the mitotic index of L1210 cells and stimulated the formation of many bi-nucleated cells, multi-nucleated cells, apoptotic cells and micronuclei, suggesting that these antitumor compounds might enhance mitotic abnormality, induce chromosomal damage or missegregation, and block cytokinesis to induce apoptosis.
Although annulated indoles may have interesting bioactivity, novel derivatives with different substitutions must be synthesized to elucidate structure-activity relationships, identify more potent antitumor lead compounds, and investigate their molecular targets and mechanisms of action.
Annulated indoles; tumor cell proliferation; DNA synthesis; interaction and fragmentation; cells with mitotic figures; several nuclei and micronuclei; cytokinesis; apoptosis
Methionine inhibits proliferation of breast and prostate cancer cells. This study aimed to determine cell cycle effects of methionine and selectivity for cancer cells.
Materials and Methods
MCF-7 (breast), LNCaP (prostate), and LS-174 (colon) cancer cells (wild-type p53), DU-145 (prostate) and SW480 (colon) cancer cells (mutated p53), and immortalized, non-tumorigenic MCF-10A (breast), BPH-1 (prostate), and NCM-460 (colon) epithelial cells were used. Cell cycle effects were assessed by flow cytometry and cell cycle-related gene expression by microarray analysis and QRT-PCR.
L-Methionine at 5 mg/ml for 72 hours (non-apoptotic) arrested cell cycle in LNCaP, DU145, and MCF-7 cells, but not in untransformed cells, nor in LS-174 cells. LNCaP and MCF-7 cells were arrested at G1, but DU-145 at S. Methionine up-regulated CDKIs and down-regulated CDKs.
L-Methionine selectively inhibits proliferation of breast and prostate cancer cells, but not non-tumorigenic cells, and may thus have therapeutic benefits. p53 status appeared to determine the cell cycle stage at which methionine acts.
Methionine; prostate; breast; colon; p53
A phase I trial consisting of panobinostat (a HDAC inhibitor), carboplatin and etoposide was condacted in patients with lung cancer. Patients and Methods: Patients received carboplatin AUC5 on day 1 and etoposide 100 mg/m2 on days 1, 2 and 3, every 21 days. Concurrent oral panobinostat was given 3 times weekly on a 2-weeks-on and 1-week-off schedule during the 4–6 cycles of chemotherapy and then continued as maintenance therapy. Results: Six evaluable patients were treated at the first dose level of panobinostat (10 mg). Dose-limiting toxicity occurred in two patients (33%) during the first cycle. One patient developed grade 4 thrombocytopenia and another grade 4 febrile neutropenia. Therefore, the study was suspended based on the pre-specified study design. No recommended phase II starting dose was established. Conclusion: The addition of panobinostat to carboplatin and etoposide was not tolerable at the lowest dose level tested in this trial. Further research and development into this combination is not recommended.
Lung cancer; panobinostat; carboplatin; etoposide
We sought to determine if complete pathologic necrosis (pathCR) predicts favorable oncologic outcome in soft tissue sarcoma (STS) patients receiving pre-operative radiation monotherapy (RT).
Patients and Methods
We evaluated 30 patients with primary STS treated with neoadjuvant RT followed by definitive resection from 2000 to 2010 at our institution. We defined ≥95% tumor necrosis as pathCR.
There were 22 STS of the extremities (73%), 7 of the retroperitoneum (23%), and one (4%) of the trunk. The median pathological percentage of tumor necrosis was 35% (range 5–100%) with three tumors (10%) demonstrating pathCR. With a median follow-up of 40 months, the 5-year local recurrence-free survival (LRFS), distant recurrence-free survival (DRFS), and overall survival (OS) for the entire cohort were 100%, 61%±11%, and 69%±11%, respectively. Among patients with pathCR, 3-year DRFS was 100% compared to 63±11% in patients without pathCR (p=0.28).
Following neoadjuvant RT for STS, pathCR is associated with a clinically but not statistically significant 37% improvement in 3-year DRFS.
Soft tissue sarcoma; preoperative radiotherapy; tumor necrosis; survival
Titanocene dichloride held great promise as a chemotherapeutic compound in preclinical studies. However, subsequent clinical trials revealed hepatoxicity and nephrotoxicity, which limited its use in clinical applications. Therefore, we used steroid pendant groups to improve the targeting of titanocene in the MCF-7 breast cancer cell line, and demonstrated a 10-fold lower effective dose compared to titanocene in in vitro assays. The aim of the present study was to test the efficacy of a titanocene functionalized with pregnenolone (Ti-Preg) in an in vivo breast cancer model.
Materials and Methods
Xenografts from the MCF7 breast cancer cell line were implanted into athymic nu/nu mice to evaluate the potential of Ti-Preg as an anti-breast cancer agent.
Ti-Preg demonstrated a significant inhibition of MCF-7 tumor growth when compared to vehicle and to titanocene controls.
Our findings demonstrate the potential of steroid pendent groups for targeting chemotherapeutics to steroid hormone-dependent cancer.
Titanocene; steroid pendant groups; TLT-1; breast cancer; titanocenyl-pregnenolone
Antiproliferative effects of proteasome inhibitors are suggested to be primarily due to effects on nuclear factor-κB (NF-κB)-dependent pathways and the induction of apoptosis. The objective of this study was to elucidate the mechanistic basis for the antiproliferative effects of the proteasome inhibitor, bortezomib, in human clear cell renal cell cancer cells (CCRCC).
Materials and Methods
von Hippel Lindau (VHL) mutation/methylation status and cytotoxic response to bortezomib was determined in a panel of CCRCC cell lines. Effects on target protein/gene expression and the role of p53 in bortezomib-mediated cytotoxicity, inhibition of proteasome activity, survivin transcript and protein expression as well as induction of p21 expression was determined in CCRCC that differed in their intrinsic sensitivity to bortezomib.
VHL status was not associated with cytotoxic response to bortezomib treatment. Cytotoxicity in cell lines that differed in intrinsic sensitivity to bortezomib correlated with sustained inhibition of proteasome activity, survivin expression and induction of p21 expression. Stable down-regulation of p53 expression by siRNA led to attenuation of bortezomib effects, survivin down-regulation and p21 induction, suggesting that cellular effects are p53-dependent.
These results demonstrate that the antiproliferative effects of bortezomib in CCRCC cells are VHL independent and dependent on pathways regulated by p53.
Bortezomib; proteasome; renal cancer; p53; VHL
In the current study, we investigated if CD44 polymorphisms are associated with increased susceptibility to breast cancer. Direct nucleotide sequencing analysis identified a novel and unique single nucleotide polymorphism (SNP, designated as CD44 Ex2+14 A>G) in the CD44 intron 1 region in 84% of breast cancer patients, which was significantly higher than that seen in normal donors. Moreover, the breast cancer patients with homozygous unique SNP in CD44 intron 1 had breast cancer at earlier ages, larger tumor burden, more regional lymph node metastases at the time of diagnosis, and higher cancer recurrence rate. There was a strong association between the unique SNP in CD44 intron 1 and CD44 expression on peripheral blood mononuclear cells. Our results suggest that CD44 polymorphism is associated with breast cancer development, and CD44 polymorphism analysis may be effectively used in the risk assessment, prediction, prevention, diagnosis and genetic epidemiological analysis of breast cancer.
Gene polymorphism; breast cancer; CD44; patient age; tumor burden
To understand the molecular response of tumor cells to therapeutic ionizing radiation (IR), we previously reported that human breast cancer cells derived following chronic exposure to fractionated ionizing radiation (MCF+FIR) showed a transient radioresistance. MCF+FIR cells also demonstrated increased activity of NF-Î B, increased expression of the mitochondrial antioxidant enzyme (MnSOD), and increased expression of a cell cycle regulatory protein (Cyclin B1). The present studies were designed to determine the relationship of NF-Î B, MnSOD and Cyclin B1 expression in cellular adaptive responses to ionizing radiation.
Materials and Methods
The first intron of the cyclin B1 gene with a putative NF-Î B element was cloned into the pGL3 luciferase reporter (pGL3CB1EI1). PGL3CB1EI1 and control NF-Î B luciferase activities were determined in MCF-7 and MCF+FIR cells treated with a single dose of radiation, over expression of the dominant negative mutant IkB (mIkB) or over expression of the SOD2 gene.
MCF+FIR cells derived from fractionated IR demonstrated increased transactivation of the pGL3CB1EI1 and NF-Î B controlled reporter activities, relative to the parental cell line. Transfection of dominant negative mutant IkB that inhibits NF-Î B nuclear translocation, inhibited pGL3CB1EI1 and NF-Î B activity, indicating the NF-Î B dependence of pGL3CB1EI1 mediated transcription. In addition, over expression of the human SOD2 gene (MnSOD) inhibited NF-Î B and pGL3CB1EI1 activity, indicating that superoxide or some species derived from superoxide may have participated in the up-regulation of reporter activity in response to chronic exposure to fractionated ionizing radiation. These results provide evidence suggesting that a signaling pathway involving NF-Î B and Cyclin B1 may contribute to adaptive radioresistance induced by chronic exposure to fractionated IR and support the conclusion that MnSOD appears to be a negative regulator of this pathway.
Cyclin B1; ionizing radiation; NF-Î B; mitochondrial antioxidant enzyme; MnSOD
Monocyte chemotactic protein-1 (MCP-1/CCL2) is released by tumor tissues, serving as a potent chemokine enabling directional homing of mononuclear cells to tumor tissue, which subsequently differentiate into tumor-associated macrophages (TAMs) via TGFβ1 signaling. TAMs readily invade tumor tissue and continue to synthesize pro-oncogenic proteins including tumor growth factors, matrix proteases (metastasis), angiogenic factors (neovascularization) and CCL2. Substances, which can attenuate or block the initial release of CCL2 have been shown to prevent cancer-associated inflammative pro-oncogenic processes. In the current study, we investigated the effects of the organosulfur compound diallyl disulfide (DADS), a natural constituent of Allium sativum (garlic) on suppression of TNFα-induced release of CCL2 from triple-negative human breast tumor (MDA-MB-231) cells. Using an initial adipokine/chemokine protein panel microarray, the data show a predominant expression profile in resting/untreated MDA-MB-231 cells for sustained release of IL6, IL8, plasminogen Activator Inhibitor 1 and TIMP1/2. Treatment with TNFα (40 ng/ml) had no effect on many of these molecules, with a single major elevation in release of CCL2 (~1,300-fold up-regulation). TNFα-induced CCL2 release was reversed by a sub-lethal concentration of DADS (100 μM), evident in antibody based assays. These findings provide evidence to support another avenue of anticancer/chemopreventative properties attributable to garlic constituents through immunomodulation.
Tumor-associated macrophages; monocyte chemotactic protein-1; garlic constituents; diallyl disulfide
Triple-negative breast cancer (TNBC) is an aggressive sub-type of breast cancer. Dasatinib and bosutinib are FDA-approved Src/Abl kinase inhibitor drugs. Dasatinib potently inhibits the proliferation of many TNBC cell lines.
Material and Methods
The cell viability/proliferation for a panel of 4 TNBC cell lines was measured by detection of cellular ATP levels and cell numbers directly determined by automated cell counting.
Bosutinib (≤1 μM) had little to no inhibitory activity on cell viability/proliferation, while dasatinib-alone generated potent IC50 values of <100 nM. Combination treatment of cells with both dasatinib and bosutinib resulted in reduced efficacy of dasatinib in all four cell lines, with two of them displaying a dramatic loss of efficacy. Direct cell counting confirmed that bosutinib enhanced cell proliferation in the presence of dasatinib.
Bosutinib potently reduced the in vitro anti-proliferative efficacy of dasatinib in TNBC cell lines. We, thereby, report on a novel drug-induced loss in dasatinib sensitivity.
Bosutinib; dasatinib; breast cancer
This study was designed to determine the efficacy and tolerability of capecitabine, oxaliplatin and bevacizumab in combination with cetuximab as first-line therapy for advanced colorectal cancer.
Patients and Methods
Patients with previously untreated advanced colorectal cancer received oxaliplatin 130 mg/m2 and bevacizumab 7.5 mg/kg every three weeks, capecitabine 850 mg/m2 twice daily on days 1–14, and cetuximab at 400 mg/m2 load and 250 mg/m2 weekly. KRAS, BRAF and PI3K mutation status from paraffin-embedded tumor samples were assessed using real-time polymerase chain reaction.
Thirty patients were evaluable for safety and efficacy. One patient had a complete response and 12 patients had a partial response, giving an overall response rate of 43% (95% confidence interval (CI) 25% – 63%). Fifteen patients had stable disease. The median time to progression was 10.3 months (95% CI, 6.8 – 16.3 months). The median overall survival was 18.8 months (95% CI, 14.2 – 23.7 months). Common grade ≥3 non-hematological toxicities were skin rash (37%), sensory neuropathy (27%) and diarrhea (17%). Grade ≥3 hematological toxicities were uncommon. Mutations in KRAS, BRAF and PI3K occurred in 34.5 %, 10.3% and 10.3% of patients respectively, but did not correlate with treatment outcome.
The addition of cetuximab to capecitabine, oxaliplatin and bevacizumab did not improve the three drug regimen activity compared to published data and was associated with significant toxicities requiring frequent dose modifications. KRAS, BRAF, and PI3K mutation status were consistent with published literature, but did not affect outcome in this small study.
Capecitabine; oxaliplatin; bevacizumab; cetuximab; phase II; metastatic colorectal
To determine the maximally tolerated dose (MTD), recommended phase II dose (RPTD) and toxicity profile of gemcitabine plus irinotecan combination.
Patients and Methods
Thirty-nine evaluable patients with advanced solid tumors were treated with gemcitabine (Gem) and irinotecan (Iri) on days 1, 8 and 15 of a 28-day cycle. Dose levels included Gem/Iri/700/50 mg/m2, 900/50, 900/75, 500/50 respectively. Dose-limiting toxicity (DLT) was assessed during cycle one; toxicity evaluation was closely monitored throughout the course of treatment. Treatment continued until disease progression or unacceptable toxicity.
DLTs primarily consisted of grade ≥3 thrombocytopenia lasting ≥4 days often accompanied by grade ≥3 neutropenia. Other grade ≥3 toxicities included vomiting, diarrhea, fatigue and elevated alkaline phosphatase. Three patients had a partial response. Stable disease as best response was seen in 16 patients, ranging from 2–18 months.
The MTD/RPTD is gemcitabine 500 mg/m2 plus irinotecan 50 mg/m2 on days 1, 8 and 15 of a 28-day cycle. Given the toxicity profile and negative results of phase III studies, no further testing of this treatment combination is recommended.
Gemcitabine; irinotecan; phase I; advanced solid tumors
To determine the maximally tolerated dose, recommended phase II dose and toxicity profile of capecitabine plus imatinib mesylate combination.
Patients and Methods
Twenty-four patients with advanced solid tumors were treated with capecitabine twice daily on days 1–14 and imatinib mesylate once daily on a 21-day cycle. Dose-limiting toxicity was assessed during the first cycle. Treatment continued until disease progression or undesirable toxicity.
Six patients were treated at capecitabine 1000 mg/m2 and imatinib mesylate 300 mg; unacceptable toxicity due to grade 2 intolerable hand-foot syndrome and/or grade ≥2 diarrhea was observed. Doses were subsequently reduced to capecitabine 750 mg/m2 and imatinib mesylate 300 mg; toxicities were better tolerated at the lower dose. Dose-limiting toxicities consisted of grade 3 diarrhea, anorexia and fatigue lasting ≥4 days. Treatment-related adverse events greater than or equal to grade 3 included anemia, diarrhea, dysuria, phosphorus and vertigo. Minor responses were observed in two patients: stable disease ≥ 6 months was observed in two out of twenty-one evaluable patients.
Full doses of capecitabine and imatinib mesylate were not tolerable. The maximum tolerated dose and the recommended phase II dose for this drug combination is capecitabine 750 mg/m2 twice daily for 1–14 days and imatinib 300 mg once daily on a 21-day cycle.
Imatinib mesylate; capecitabine; phase I; advanced solid tumors