Gemcitabine is a chemotherapeutic agent frequently used by for the treatment of several malignancies both in the adjuvant and metastatic setting. Although myelosuppression is the most adverse event of this therapy, gemcitabine might induce severe pulmonary toxicities. We describe a case of pulmonary veno-occlusive disease (PVOD) related to gemcitabine.
The patient was an 83-year-old man with a metastatic pancreatic cancer who was treated by gemcitabine as first-line therapy. He was in good health and received no other chemotherapy. A dose of 1000 mg/m2 of gemcitabine was administered over a 30-minute intravenous infusion on days 1, 8, and 15 of a 28-day cycle. After a period of 6 months, a complete response was observed. Nevertheless, the patient developed a severe dyspnea, with arterial hypoxemia and very low lung diffusion for carbon monoxide. A CT scan showed diffuse ground glass opacities with septal lines, bilateral pleural effusion, and lymph node enlargement. On echocardiography, there was a suspicion of pulmonary hypertension with elevated systolic pulmonary artery pressure and normal left ventricular pressures. Right heart catheterization confirmed pulmonary hypertension and normal pulmonary artery occlusion pressure. Diagnosis of PVOD was made, and a gemcitabine-induced toxicity was suspected. A symptomatic treatment was started. At last follow-up, patient was in functional class I with near-normal of CT scan, arterial blood gases, and echocardiography. A gemcitabine-induced PVOD is the more likely diagnosis.
gemcitabine; pancreatic cancer; pulmonary toxicities; veno occlusive disease
Patient: Male, 59 • Male, 85 • Male, 27
Final Diagnosis: refractory metastatic rectal cancer
Clinical Procedure: Chemotherapy
Challenging differential diagnosis
Rectal linitis plastica (RLP) is a rare disease with poor outcome. It is often accompanied by a delayed histopathological diagnosis, primarily due to submucosal disease. A concentric ring pattern or “target sign” on T2-weighted magnetic resonance imaging (MRI) has been proposed as being characteristic for early suspicion. Even though RLP is more aggressive and has poorer survival than other rectal adenocarcinomas, no specific treatment is recommended. In this case report of 3 patients, we challenge the sensitivity of the characteristic radiological pattern, and we review the existing data for a treatment strategy.
One patient presented classic clinical characteristics of RLP with young age and advanced stage at diagnosis, with chemo-refractory disease and rapid fatal evolution. Biopsies confirmed the RLP with the presence of signet-ring cells (SRC) in a strong desmoplastic stromal reaction. However, the characteristic concentric ring pattern was absent. Instead, he had a large vegetative lesion with important tumor infiltration in mesorectum and pelvic organs, with major lymph node involvement. The 2 other patients presented resectable locally advanced disease with characteristic concentric ring pattern.
No clinical and radiological responses were observed to neo-adjuvant chemoradiotherapy (CRT), including 1 patient with non-resectable disease at surgery and another with upstaged disease at pathological specimen after resection. However, data suggest 2 types of RLP: about half of patients are extremely sensitive to CRT with pathological complete response, and the other half are highly resistant with no response to CRT. Current data are insufficient to distinguish between these 2 populations.
The absence of a concentric ring pattern should not eliminate the suspicion of RLP, especially in young patients with aggressive clinical presentation.
There are probably 2 types of RLP in terms of chemoradiosensitivity, and neoadjuvant CRT could delay the curative-intent surgery in refractory patients. Future molecular analysis of the tumor and its environment are required to characterize the 2 different forms of RLP to develop more personalized treatment strategies.
Carcinoma, Signet Ring Cell; Linitis Plastica; Rectal Neoplasms
Nowadays, immunotherapy represents one promising approach for cancer treatment. Recently, spectacular results of cancer immunotherapy clinical trials have confirmed the crucial role of immune system in cancer regression. Therapeutic cancer vaccine represents one widely used immunotherapy strategy to stimulate tumor specific T cell responses but clinical impact remains disappointing in targeting CD8 T cells. Although CD8 T cells have been initially considered to be the main protagonists, it is now clear that CD4 T cells also play a critical role in antitumor response. In this article, we discuss the role of tumor antigen-specific CD4 T cell responses and how we can target these cells to improve cancer vaccines.
CD4 T cell; tumor antigen; helper peptide; cancer vaccine
The benefit of preoperative chemotherapy in resectable gastroesophageal adenocarcinomas was not observed in signet ring cell subtype. However, the potential interest of taxane-based preoperative chemotherapy on this subtype is still an unresolved issue. Nineteen patients with localized signet ring cell adenocarcinomas received taxane-based regimens, and 17 patients underwent surgery. Complete resection was achieved in 80 %, and median overall survival was 40.8 months (95 % confidence interval (CI), 20.2—not reached). Even though one patient achieved a complete pathological response, seven patients had an upstaging of their tumors at surgery. The potential benefits of taxane-based chemotherapy seem to be limited to a reduced number of patients.
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Signet ring cell; Gastroesophageal cancer; Gastric cancer; Preoperative; Neoadjuvant; Taxane; Docetaxel; Paclitaxel
Cisplatin/gemcitabine association has been a standard of care for first-line regimen in advanced biliary tract cancer nevertheless oxaliplatin/gemcitabine regimen is frequently preferred. Because comparative effectiveness in clinical outcomes of cisplatin- versus oxaliplatin-containing chemotherapy is not available, a systematic review of studies assessing cisplatin/gemcitabine or oxaliplatin/gemcitabine chemotherapies in advanced biliary tract cancer was performed. Published studies evaluating cisplatin/gemcitabine or oxaliplatin/gemcitabine in advanced biliary tract cancer were included. Each study was weighted according to the number of patients included. The primary objective was to assess weighted median of medians overall survival (mOS) reported for both regimens. Secondary goals were to assess weighted median of medians progression-free survival (mPFS) and toxic effects were pooled and compared within each arm. Thirty-three studies involving 1470 patients were analyzed. In total, 771 and 699 patients were treated by cisplatin/gemcitabine and oxaliplatin/gemcitabine, respectively. Weighted median of mOS was 9.7 months in cisplatin group and 9.5 months in oxaliplatin group. Cisplatin-based chemotherapy was significantly associated with more grade 3 and 4 asthenia, diarrhea, liver toxicity, and hematological toxicity. Sensitivity analysis including only the studies with the standard regimen of cisplatin (25–35 mg/m2 administered on days 1 and 8) showed that the weighted median of mOS increased from 9.7 to 11.7 months but Gem/CDDP regimen remained more toxic than Gemox regimen. These results suggest that the Gem/CDDP regimen with cisplatin (25–35 mg/m2) administered on days 1 and 8 is associated with survival advantage than Gemox regimen but with addition of toxicity.
Biliary tract cancer; cisplatin; gemcitabine; oxaliplatin
Here, we report and investigate the genomic alterations of two novel cases of Non-Hodgkin Lymphoma (NHL) in children with Williams-Beuren syndrome (WBS), a multisystem disorder caused by 7q11.23 hemizygous deletion. Additionally, we report the case of a child with NHL and a somatic 7q11.23 deletion. Although the WBS critical region has not yet been identified as a susceptibility locus in NHL, it harbors a number of genes involved in DNA repair. The high proportion of pediatric NHL reported in WBS is intriguing. Therefore, the role of haploinsufficiency of genes located at 7q11.23 in lymphomagenesis deserves to be investigated.
Electronic supplementary material
The online version of this article (doi:10.1186/s13045-014-0082-4) contains supplementary material, which is available to authorized users.
Williams-Beuren syndrome; Non-Hodgkin Lymphoma; 7q11.23; Cancer predisposition; DNA repair
There are several reports demonstrating the role of CD8 T cells against Leishmania species. Therefore peptide vaccine might represent an effective approach to control the infection. We developed a rational polytope-DNA construct encoding immunogenic HLA-A2 restricted peptides and validated the processing and presentation of encoded epitopes in a preclinical mouse model humanized for the MHC-class-I and II.
Methods and Findings
HLA-A*0201 restricted epitopes from LPG-3, LmSTI-1, CPB and CPC along with H-2Kd restricted peptides, were lined-up together as a polytope string in a DNA construct. Polytope string was rationally designed by harnessing advantages of ubiquitin, spacers and HLA-DR restricted Th1 epitope. Endotoxin free pcDNA plasmid expressing the polytope was inoculated into humanized HLA-DRB1*0101/HLA-A*0201 transgenic mice intramuscularly 4 days after Cardiotoxin priming followed by 2 boosters at one week interval. Mice were sacrificed 10 days after the last booster, and splenocytes were subjected to ex-vivo and in-vitro evaluation of specific IFN-γ production and in-vitro cytotoxicity against individual peptides by ELISpot and standard chromium-51(51Cr) release assay respectively. 4 H-2Kd and 5 HLA-A*0201 restricted peptides were able to induce specific CD8 T cell responses in BALB/C and HLA-A2/DR1 mice respectively. IFN-γ and cytolytic activity together discriminated LPG-3-P1 as dominant, LmSTI-1-P3 and LmSTI-1-P6 as subdominant with both cytolytic activity and IFN-γ production, LmSTI-1-P4 and LPG-3-P5 as subdominant with only IFN-γ production potential.
Here we described a new DNA-polytope construct for Leishmania vaccination encompassing immunogenic HLA-A2 restricted peptides. Immunogenicity evaluation in HLA-transgenic model confirmed CD8 T cell induction with expected affinities and avidities showing almost efficient processing and presentation of the peptides in relevant preclinical model. Further evaluation will determine the efficacy of this polytope construct protecting against infectious challenge of Leishmania. Fortunately HLA transgenic mice are promising preclinical models helping to speed up immunogenicity analysis in a human related mouse model.
Gemcitabine/Cisplatin (Gem/CDDP) combination has demonstrated a clear survival advantage over gemcitabine alone and has become a new standard in advanced Biliary Tract Carcinoma (aBTC). However, Gemcitabine/Oxaliplatin (GEMOX) combination and Gemcitabine/Carboplatin (Gem/Carb) combination regimens have shown efficacy in phase II trials and there is no comparative study between different platinum salts.
We assessed the efficacy and safety of different platinum-based chemotherapies at first line in aBTC patients. We also analysed the second-line chemotherapy.
Sixty-four consecutive patients with aBTC diagnosed between 1998 and 2010 were included for analysis. At first line chemotherapy, 44 patients received one day GEMOX regimen (gemcitabine 1000 mg/m2 and oxaliplatin 100 mg/m2 Day 1, every 2 weeks), and 20 patients received Gem/Carb regimen (gemcitabine at 1000 mg/m2 Days 1 and 8 with carboplatin delivered according to an area-under-the-curve (AUC) 5 at day 1, every 3 weeks). At second line, a total of 16 patients received a fluoropyrimidine-based chemotherapy.
With GEMOX regimen, median progression-free survival (PFS) was 3.7 months (95%CI, 2.4 to 5) and median overall survival (OS) was 10.5 months (95%CI, 6.4 to14.7). The main toxicity was peripheral neuropathy (20% grade 2 and 7% grade 3). Grade 3/4 haematological toxicities were rare.
With Gem/Carb regimen, PFS was 2.5 months (95%CI, 2.1 to 3.7) and OS was 4.8 months (95%CI, 3.7 to 5.8). The main grade 3/4 toxicities were haematological: anaemia (45%), thrombocytopenia (45%), and neutropenia (40%).
At second-line, fluoropyrimidine-based chemotherapy was feasible in only a fourth of the patients. The median OS was 5.3 months (95%CI, 4.1 to 6.6), and median PFS was 4.0 months (95%CI, 2.6 to 5.5).
One day GEMOX regimen has a favourable toxicity profile and could be an alternative to standard Gem/CDDP regimen, in particular in unfit patients for CDDP.
At second-line, selective patients may benefit from fluoropyrimidine-based chemotherapy.
Current cancer immunotherapies predominantly rely on CD8+ T cells to fight against tumors. However accumulative evidence showed that proinflammatory CD4+ helper T cells are critical determinants of effective antitumor immunity. The utilization of universal tumor-reactive helper peptides from telomerase represents a powerful approach to the fully use of CD4+ T cell-based immunotherapy.
CD4 T cell; helper peptide; telomerase; cancer vaccine
Hypersensitivity pneumonitis (HP) is an immunoallergic disease characterized by a prominent interstitial infiltrate composed predominantly of lymphocytes secreting inflammatory cytokines. Dendritic cells (DCs) are known to play a pivotal role in the lymphocytic response. However, their cross talk with microorganisms that cause HP has yet to be elucidated. This study aimed to investigate the initial interactions between human monocyte-derived DCs (MoDCs) and four microorganisms that are different in nature (Saccharopolyspora rectivirgula [actinomycetes], Mycobacterium immunogenum [mycobacteria], and Wallemia sebi and Eurotium amstelodami [filamentous fungi]) and are involved in HP. Our objectives were to determine the cross talk between MoDCs and HP-causative agents and to determine whether the resulting immune response varied according to the microbial extract tested. The phenotypic activation of MoDCs was measured by the increased expression of costimulatory molecules and levels of cytokines in supernatants. The functional activation of MoDCs was measured by the ability of MoDCs to induce lymphocytic proliferation and differentiation in a mixed lymphocytic reaction (MLR). E. amstelodami-exposed (EA) MoDCs expressed higher percentages of costimulatory molecules than did W. sebi-exposed (WS), S. rectivirgula-exposed (SR), or M. immunogenum-exposed (MI) MoDCs (P < 0.05, Wilcoxon signed-rank test). EA-MoDCs, WS-MoDCs, SR-MoDCs, and MI-MoDCs induced CD4+ T cell proliferation and a Th1-polarized immune response. The present study provides evidence that, although differences were initially observed between MoDCs exposed to filamentous fungi and MoDCs exposed to bacteria, a Th1 response was ultimately promoted by DCs regardless of the microbial extract tested.
The QSOX1 protein (Quiescin Sulfhydryl oxidase 1) catalyzes the formation of disulfide bonds and is involved in the folding and stability of proteins. More recently, QSOX1 has been associated with tumorigenesis and protection against cellular stress. It has been demonstrated in our laboratory that QSOX1 reduces proliferation, migration and invasion of breast cancer cells in vitro and reduces tumor growth in vivo. In addition, QSOX1 expression has been shown to be induced by oxidative or ER stress and to prevent cell death linked to these stressors. Given the function of QSOX1 in these two processes, which have been previously linked to autophagy, we wondered whether QSOX1 might be regulated by autophagy inducers and play a role in this catabolic process. To answer this question, we used in vitro models of breast cancer cells in which QSOX1 was overexpressed (MCF-7) or extinguished (MDA-MB-231). We first showed that QSOX1 expression is induced following amino acid starvation and maintains cellular homeostasis. Our results also indicated that QSOX1 inhibits autophagy through the inhibition of autophagosome/lysosome fusion. Moreover, we demonstrated that inhibitors of autophagy mimic the effect of QSOX1 on cell invasion, suggesting that its role in this process is linked to the autophagy pathway. Previously published data demonstrated that extinction of QSOX1 promotes tumor growth in NOG mice. In this study, we further demonstrated that QSOX1 null tumors present lower levels of the p62 protein. Altogether, our results demonstrate for the first time a role of QSOX1 in autophagy in breast cancer cells and tumors.
Bevacizumab plus fluoropyrimidine-based chemotherapy is standard treatment for first-line and second-line metastatic colorectal cancer (mCRC). However, to date, there is no current biomarker predictive for the benefit of bevacizumab use for these patients. Preclinical data suggest that the presence of the primary tumor could be involved in less efficient antitumor activity of antiangiogenic agents, but no clinical data currently support this hypothesis.
We performed a retrospective analysis of factors associated with overall survival (OS) in a study cohort of 409 mCRC patients. Univariate and multivariate Cox proportional hazard regression models were used to assess the influence of primary tumor resection and bevacizumab use on OS. We evaluated associations linking bevacizumab use and OS among patients who previously underwent or did not undergo primary tumor resection. Results were externally validated in a second independent cohort of 328 mCRC patients.
In the study cohort, bevacizumab use and resection of the primary tumor were associated with improved OS. However, subgroup analyses indicate that bevacizumab did not influence survival of patients bearing a primary colorectal tumor (hazard ratio (HR) 0.98, 95 % confidence interval (CI) 0.60–1.61, log-rank test P = 0.6). By contrast, the survival benefit of bevacizumab was restricted to patients who previously underwent primary tumor resection (HR 0.71, 95 % CI 0.55–0.92, P = 0.009). Similar results were observed in the validation cohort.
Addition of bevacizumab to chemotherapy is associated with improvement of OS only in patients with primary tumor resection. These data support the rationale to validate prospectively the influence of primary tumor resection on bevacizumab antitumor effect in synchronous mCRC.
Electronic supplementary material
The online version of this article (doi:10.1245/s10434-013-3463-y) contains supplementary material, which is available to authorized users.
Optimization of chemotherapy effectiveness in metastatic colorectal cancers (mCRC) is a major endpoint to enhance the possibility of curative intent surgery. FOLFIRI3 has shown promising results as second-line chemotherapy for mCRC patients previously exposed to oxaliplatin. The clinical efficacy of FOLFIRI3 was never determined in association with bevacizumab in non-previously treated mCRC patients.
We conducted a phase II clinical trial to characterize the response rate and toxicity profile of FOLFIRI3-bevacizumab as initial treatment for mCRC. Sixty-one patients enrolled in 3 investigation centers were treated with FOLFIRI3-bevacizumab (median of 10 cycles) followed by a maintenance therapy combining bevacizumab and capecitabine. Levels of plasma angiopoietin-2 (Ang-2) were measured by enzyme-linked immunosorbent assay at baseline.
Overall response rate (ORR) was 66.7% (8% of complete and 58% of partial responses). The disease control rate was 91.7%. After a median time of follow-up of 46.7 months, 56 patients (92%) had progressed or died. The median progression free survival (PFS) was 12.7 months (95% confidence interval (CI) 9.7-15.8 months). The median overall survival (OS) was 24.5 months (95% CI: 10.6-38.3 months). Twenty-one patients underwent curative intent-surgery including 4 patients with disease initially classified as unresectable. Most common grade III-IV toxicities were diarrhea (15%), neutropenia (13%), asthenia (10%), and infections (4%). Hypertension-related medications needed to be increased in 3 patients. In multivariate analysis, surgery of metastases and Ang-2 levels were the only independent prognostic factors for PFS and OS. Indeed, baseline level of Ang-2 above 5 ng/mL was confirmed as an independent prognostic factor for progression free survival (HR = 0.357; 95% CI: 0.168-0.76, p = 0.005) and overall survival (HR = 0.226; 95% CI: 0.098-0.53, p = 0.0002).
As front-line therapy, FOLFIRI-3-bevacizumab is associated with an acceptable toxicity and induced promising objective response rates. However, unfavorable clinical outcomes were observed in patients with high levels of angiopoietin-2.
Colorectal cancer; Bevacizumab; FOLFIRI3; Irinotecan; Angiopoietin-2
Longitudinal analysis of health-related quality of life (HRQoL) remains unstandardized and compromises comparison of results between trials.
In oncology, despite available statistical approaches, results are poorly used to change standards of care, mainly due to lack of standardization and the ability to propose clinical meaningful results. In this context, the time to deterioration (TTD) has been proposed as a modality of longitudinal HRQoL analysis for cancer patients. As for tumor response and progression, we propose to develop RECIST criteria for HRQoL.
Several definitions of TTD are investigated in this paper. We applied this approach in early breast cancer and metastatic pancreatic cancer with a 5-point minimal clinically important difference. In breast cancer, TTD was defined as compared to the baseline score or to the best previous score. In pancreatic cancer (arm 1: gemcitabine with FOLFIRI.3, arm 2: gemcitabine alone), the time until definitive deterioration (TUDD) was investigated with or without death as event.
In the breast cancer study, 381 women were included. The median TTD was influenced by the choice of the reference score. In pancreatic cancer study, 98 patients were enrolled. Patients in Arm 1 presented longer TUDD than those in Arm 2 for most of HRQoL scores. Results of TUDD were slightly different according to the definition of deterioration applied.
Currently, the international ARCAD group supports the idea of developing RECIST for HRQoL in pancreatic and colorectal cancer with liver metastasis, with a view to using HRQoL as a co-primary endpoint along with a tumor parameter.
Electronic supplementary material
The online version of this article (doi:10.1007/s11136-013-0583-6) contains supplementary material, which is available to authorized users.
Health-related quality of life; Clinical trials; Oncology; Longitudinal analysis; Time to deterioration
Insights into antitumor T-cell responses may help the development of more efficient treatments for lung cancer. The interplay between preexisting antitumor CD4+ T-cell responses and platinum-based chemotherapy is crucial to improve patient survival. Accumulating evidence confirms that selecting cancer patients in whom chemotherapy can activate an anticancer immune response would largely improve the success of novel therapeutic approaches.
immunomonitoring; models of immunochemotherapy and immunoradiotherapy; new targets; telomerase
The gene quiescin/sulfhydryl oxidase 1, QSOX1, encodes an enzyme directed to the secretory pathway and excreted into the extracellular space. QSOX1 participates in the folding and stability of proteins and thus could regulate the biological activity of its substrates in the secretory pathway and/or outside the cell. The involvement of QSOX1 in oncogenesis has been studied primarily in terms of its differential expression in systemic studies. QSOX1 is overexpressed in prostate cancers and in pancreatic adenocarcinoma. In contrast, QSOX1 gene expression is repressed in endothelial tumors. In the present study, we investigated the role of QSOX1 in breast cancer.
We analyzed QSOX1 mRNA expression in a cohort of 217 invasive ductal carcinomas of the breast. Moreover, we investigated QSOX1's potential role in regulating tumor growth and metastasis using cellular models in which we overexpressed or extinguished QSOX1 and xenograft experiments.
We showed that the QSOX1 expression level is inversely correlated to the aggressiveness of breast tumors. Our results show that QSOX1 leads to a decrease in cell proliferation, clonogenic capacities and promotes adhesion to the extracellular matrix. QSOX1 also reduces the invasive potential of cells by reducing cell migration and decreases the activity of the matrix metalloproteinase, MMP-2, involved in these mechanisms. Moreover, in vivo experiments show that QSOX1 drastically reduces the tumor development.
Together, these results suggest that QSOX1 could be posited as a new biomarker of good prognosis in breast cancer and demonstrate that QSOX1 inhibits human breast cancer tumorogenesis.
Neuropilins, initially characterized as neuronal receptors, act as co-receptors for cancer related growth factors and were recently involved in several signaling pathways leading to cytoskeletal organization, angiogenesis and cancer progression. Then, we sought to investigate the ability of neuropilin-2 to orchestrate epithelial-mesenchymal transition in colorectal cancer cells. Using specific siRNA to target neuropilin-2 expression, or gene transfer, we first observed that neuropilin-2 expression endows HT29 and Colo320 for xenograft formation. Moreover, neuropilin-2 conferred a fibroblastic-like shape to cancer cells, suggesting an involvement of neuropilin-2 in epithelial-mesenchymal transition. Indeed, the presence of neuropilin-2 in colorectal carcinoma cell lines was correlated with loss of epithelial markers such as cytokeratin-20 and E-cadherin and with acquisition of mesenchymal molecules such as vimentin. Furthermore, we showed by surface plasmon resonance experiments that neuropilin-2 is a receptor for transforming-growth factor-β1. The expression of neuropilin-2 on colon cancer cell lines was indeed shown to promote transforming-growth factor-β1 signaling, leading to a constitutive phosphorylation of the Smad2/3 complex. Treatment with specific TGFβ-type1 receptor kinase inhibitors restored E-cadherin levels and inhibited in part neuropilin-2-induced vimentin expression, suggesting that neuropilin-2 cooperates with TGFβ-type1 receptor to promote epithelial-mesenchymal transition in colorectal cancer cells. Our results suggest a direct role of NRP2 in epithelial-mesenchymal transition and highlight a cross-talk between neuropilin-2 and TGF-β1 signaling to promote cancer progression. These results suggest that neuropilin-2 fulfills all the criteria of a therapeutic target to disrupt multiple oncogenic functions in solid tumors.
Recent investigations highlighted strong similarities between neural crest migration during embryogenesis and metastatic processes. Indeed, some families of axon guidance molecules were also reported to participate in cancer invasion: plexins/semaphorins/neuropilins, ephrins/Eph receptors, netrin/DCC/UNC5. Neuropilins (NRPs) are transmembrane non tyrosine-kinase glycoproteins first identified as receptors for class-3 semaphorins. They are particularly involved in neural crest migration and axonal growth during development of the nervous system. Since many types of tumor and endothelial cells express NRP receptors, various soluble molecules were also found to interact with these receptors to modulate cancer progression. Among them, angiogenic factors belonging to the Vascular Endothelial Growth Factor (VEGF) family seem to be responsible for NRP-related angiogenesis. Because NRPs expression is often upregulated in cancer tissues and correlated with poor prognosis, NRPs expression might be considered as a prognostic factor. While NRP1 was intensively studied for many years and identified as an attractive angiogenesis target for cancer therapy, the NRP2 signaling pathway has just recently been studied. Although NRP genes share 44% homology, differences in their expression patterns, ligands specificities and signaling pathways were observed. Indeed, NRP2 may regulate tumor progression by several concurrent mechanisms, not only angiogenesis but lymphangiogenesis, epithelial-mesenchymal transition and metastasis. In view of their multiples functions in cancer promotion, NRPs fulfill all the criteria of a therapeutic target for innovative anti-tumor therapies. This review focuses on NRP-specific roles in tumor progression.
neuropilins; cancer; angiogenesis; lymphangiogenesis; targeted therapies
Myeloid-derived suppressor cells (MDSCs) have been identified in humans and mice as a population of immature myeloid cells with the ability to suppress T cell activation. They accumulate in tumor-bearing mice and humans and have been shown to contribute to cancer development. Here, we have isolated tumor-derived exosomes (TDEs) from mouse cell lines and shown that an interaction between TDE-associated Hsp72 and MDSCs determines the suppressive activity of the MDSCs via activation of Stat3. In addition, tumor-derived soluble factors triggered MDSC expansion via activation of Erk. TDE-associated Hsp72 triggered Stat3 activation in MDSCs in a TLR2/MyD88-dependent manner through autocrine production of IL-6. Importantly, decreasing exosome production using dimethyl amiloride enhanced the in vivo antitumor efficacy of the chemotherapeutic drug cyclophosphamide in 3 different mouse tumor models. We also demonstrated that this mechanism is relevant in cancer patients, as TDEs from a human tumor cell line activated human MDSCs and triggered their suppressive function in an Hsp72/TLR2-dependent manner. Further, MDSCs from cancer patients treated with amiloride, a drug used to treat high blood pressure that also inhibits exosome formation, exhibited reduced suppressor functions. Collectively, our findings show in both mice and humans that Hsp72 expressed at the surface of TDEs restrains tumor immune surveillance by promoting MDSC suppressive functions.
DC derived-exosomes are nanomeric vesicles harboring functional MHC/peptide complexes capable of promoting T cell immune responses and tumor rejection. Here we report the feasability and safety of the first Phase I clinical trial using autologous exosomes pulsed with MAGE 3 peptides for the immunization of stage III/IV melanoma patients. Secondary endpoints were the monitoring of T cell responses and the clinical outcome.
Patients and methods
Exosomes were purified from day 7 autologous monocyte derived-DC cultures. Fifteen patients fullfilling the inclusion criteria (stage IIIB and IV, HLA-A1+, or -B35+ and HLA-DPO4+ leukocyte phenotype, tumor expressing MAGE3 antigen) were enrolled from 2000 to 2002 and received four exosome vaccinations. Two dose levels of either MHC class II molecules (0.13 versus 0.40 × 1014 molecules) or peptides (10 versus 100 μg/ml) were tested. Evaluations were performed before and 2 weeks after immunization. A continuation treatment was performed in 4 cases of non progression.
The GMP process allowed to harvest about 5 × 1014 exosomal MHC class II molecules allowing inclusion of all 15 patients. There was no grade II toxicity and the maximal tolerated dose was not achieved. One patient exhibited a partial response according to the RECIST criteria. This HLA-B35+/A2+ patient vaccinated with A1/B35 defined CTL epitopes developed halo of depigmentation around naevi, a MART1-specific HLA-A2 restricted T cell response in the tumor bed associated with progressive loss of HLA-A2 and HLA-BC molecules on tumor cells during therapy with exosomes. In addition, one minor, two stable and one mixed responses were observed in skin and lymph node sites. MAGE3 specific CD4+ and CD8+ T cell responses could not be detected in peripheral blood.
The first exosome Phase I trial highlighted the feasibility of large scale exosome production and the safety of exosome administration.
exosomes; dendritic cells; phase I trial; cancer vaccine; immunotherapy
Mutant isoforms of the KIT or PDGF receptors expressed by gastrointestinal stromal tumors (GISTs) are considered the therapeutic targets for STI571 (imatinib mesylate; Gleevec), a specific inhibitor of these tyrosine kinase receptors. Case reports of clinical efficacy of Gleevec in GISTs lacking the typical receptor mutations prompted a search for an alternate mode of action. Here we show that Gleevec can act on host DCs to promote NK cell activation. DC-mediated NK cell activation was triggered in vitro and in vivo by treatment of DCs with Gleevec as well as by a loss-of-function mutation of KIT. Therefore, tumors that are refractory to the antiproliferative effects of Gleevec in vitro responded to Gleevec in vivo in an NK cell–dependent manner. Longitudinal studies of Gleevec-treated GIST patients revealed a therapy-induced increase in IFN-γ production by NK cells, correlating with an enhanced antitumor response. These data point to a novel mode of antitumor action for Gleevec.
Animals; Apoptosis; drug effects; Bone Marrow Cells; physiology; Hematopoietic Stem Cell Transplantation; Immune Tolerance; Immunosuppressive Agents; pharmacology; Mice; Mice, Inbred BALB C; Photopheresis; Sirolimus; pharmacology; T-Lymphocytes, Regulatory; immunology; Transplantation Conditioning