Background: The atypical chemokine receptor, CXCR7, has been shown to play an important role in the progression of several types of cancer. However, there have been few reports on the biological role of CXCR7 in head and neck squamous cell carcinoma (HNSCC). In this study, we investigated the functional role of CXCR7 and the underlying molecular mechanism of disease progression in HNSCC. Methods: We examined the association between CXCR7 expression and clinicopathological characteristics in 103 cases of HNSCC using tissue microarrays by immunohistochemical staining. The biological roles of CXCR7 and CXCR7-mediated signaling pathways were investigated in HNSCC cell through CXCR7 overexpression and treatment of SDF-1α, a major ligand of CXCR7, as well as knockdown of CXCR7 in vitro and in vivo. Results: CXCR7 was differentially expressed in human HNSCC tissues. High expression of CXCR7 was significantly related to depth of tumor invasion (P = 0.007), lymph node metastasis (P = 0.004), and tumor stage (P = 0.02). Overexpression of CXCR7 dramatically enhanced cell migration and invasion in HNSCC cells in vitro, and promoted lymph node metastasis in vivo. CXCR7 knockdown using siRNA in HNSCC cells recovered the cell migratory and invasive behavior of HNSCC cells. CXCR7 overexpression also induced the epithelial-mesenchymal transition. Vimentin, Slug, and Twist were increased but E-cadherin and Ep-CAM were decreased by CXCR7 expression. Akt phosphorylation and Smad2 signaling activation were induced in HNSCC cells with CXCR7 overexpression. Treatment with a PI3K inhibitor reduced Slug and Twist levels while suppression of Smad2 signaling by siRNA reduced Akt phosphorylation, as well as Slug and Twist. Furthermore, inhibition of Smad2 decreased tumor cell migration and invasion in HNSCC. Conclusions: CXCR7 expression was associated with an aggressive tumor behavior in HNSCC. CXCR7 contributed to cell migration and invasion of HNSCC cell through the Smad2/Akt signaling axis in vitro, and was involved in lymph node metastasis in vivo, suggesting that CXCR7 might be a therapeutic target for the treatment of HNSCC. Legal entity responsible for the study: Hyo Jin Lee. Funding: Cancer Research Institute of CNU. Disclosure: All authors have declared no conflicts of interest.

The aim of this study was to determine whether Krüppel-like factor 5(KLF5) expression in pre-irradiation tumor biopsies is a useful predictive marker of tumor response in patients with rectal cancer This study included 60 human colon tumor pre-irradiation specimens. Expression was studied by immunohistochemistry(IHC) using scoring system(0-15). Functional roles of KLF5 were analysed by over-expression of the protein in colon cancer cell line. Protein interactions were studied by stress induction such as chemo or radiation and MTT assays. Complete remission was achieved by 9(18%) patients. Tumor regression was significantly related with p53 and KLF5(p = 0.021,p = 0.004,respectfully). The KLF5 IHC score significantly correlated with KRAS mutation status(5.92 ± 2.54 vs 8.44 ± 1.94,p = 0.006),and pCR(4.11 ± 2.61 vs 6.68 ± 2.43,p = 0.005). In HCT 116 cell line, KLF5 protein was significantly increased after radiation therapy, suggesting that KLF5 via cyclin D1, b-catenin. HCT 116 with KLF5 overexpression exhibited significantly better cell viability compared to control cells in MTT assay. Overexpression of KLF5 might be predictive of poor tumor regression after preoperative CRT. Our study suggests IHC of KLF5 as a possible biomarker to predict complete remission and T-down staging. Our study suggests KLF5 has a role to get resistance to chemo-radiation therapy in rectal cancer treated preoperative CRT.

Introduction: Reactive oxygen species (ROS) produced by docosahexaenoic acid (DHA) have an important function in cancer cell death.However, the exact mechanism of ROS production, after DHA stimulation, is not clearly understood.Here, we determined that elevated levels of ROS generated by mitochondrial respiration is directly associated with DHA-induced cervical cancer cell death.Material and Method: The effects of DHA on cell proliferation and cell cycle were examined by MTT assay and FACS.DHA-induced apoptosis was analyzed using the TUNEL assay, caspase activity assay, and western blot.Dihydroethidium (DHE) was used for reactive oxygen species (ROS) measurement in cytosol.MitoSox was performed for ROS measurement in mitochondria.Results and Discussion: The levels of caspase 3 activity, TUNELpositive staining cells and Sub-G1 portion were markedly increased in DHA-treated cancer cells, suggesting that apoptosis is responsible for the DHA-induced cervical cancer cell death.Furthermore, DHA was able to induce both mitochondrial complex I substrate-and complex II substratesupported mitochondrial ROS production in isolated mitochondria from rodent liver.Meanwhile, a reduction in oxygen consumption rate and an increase in mitochondrial ROS production as measured by MitoSOX, were also observed in DHA-treated cancer cells, indicating that DHA can directly act on mitochondrial respiration and enhance ROS generation.The role of DHA-induced mitochondrial ROS production in apoptosis was further identified by the findings that DHA reduced the mitochondrial membrane potential, resulting in cardiolipin oxidation and cytochrome c release from mitochondria, and that N-acetylcysteine, an antioxidant almost completely blocked these processes as well as ROS production occurred in mitochondria and remarkably reversed the apoptotic cell death triggered by DHA. Conclusion:From the results presented here, we conclude that mitochondria actively participate in the DHA-induced apoptotic cell death

4028 Background: We conducted a randomized phase II study to compare continuous vs. intermittent S-1 + oxaliplatin (SOX) after induction of 6 cycles of SOX in patients (pts) with metastatic gastric cancer (MGC). Methods: Pts >18 yrs with chemo-naive MGC, normal organ function, ECOG PS 0-2, and measurable or evaluable lesion(s) were initially given an induction treatment of 6 cycles of SOX (S-1 40 mg/m2 bid on D1-14 + oxaliplatin 130 mg/m2 on D1 q 3 wks). Pts with CR/PR or SD were randomized to continue SOX (arm A) until progression/intolerable toxicity or discontinue until progression when SOX was re-administered (arm B). The primary endpoint was overall survival (OS), and secondary endpoints included progression-free survival (PFS), response rate, safety, quality of life, and biomarker correlative studies. Results: From July 2007 to Dec 2010, a total of 250 pts entered into the study. Median age was 53 yrs (range, 24-69); PS 0/1/2=13/219/18; M/F=162/88. Three pts did not receive treatment and 126 (50.4%) discontinued treatment before or at the completion of 6 cycles of SOX due to progression (45.6%), pt refusal (2.8%), or adverse events (2.0%). A total of 121 pts were randomized: 59 (48.8%) to arm A and 62 (51.2%) to arm B. Clinical characteristics were well balanced between arms. SOX continuation resulted in a significant reduction in the risk of progression (median PFS, 10.5 months for arm A vs. 7.2 months for arm B; HR=0.57, 95% CI 0.39-0.84, p=0.005). With a median follow-up of 34.0 months (range, 10.5-53.3 months), there was no significant difference in OS (median OS, 22.6 months for arm A vs. 22.7 months for arm B; HR, 0.79, 95% CI 0.51-1.25, p=0.31). Arm A had higher rates of grade 3/4 fatigue (28.8% vs. 8.1%, p=0.004) and neuropathy (25.4% vs. 8.1%, p=0.014) but other grade 3/4 hematologic (neutropenia, 35.6% vs. 32.3%; thrombocytopenia, 23.7% vs. 21.0%; anemia, 15.3% vs. 6.5%) or non-hematologic toxicity rates were not significantly different. Conclusions: Continuous chemotherapy with SOX after induction therapy improved PFS but not OS. Supported by NCC Grant 1010180 (S-1 and oxaliplatin was provided by JEIL Pharm. Co., Ltd. and sanofi-aventis Korea Co., Ltd., respectively).

Conclusion:Collectively, our results demonstrate that DHA induces autophagy through the ROS-mediated mTOR inactivation in p53 mutant prostate cancer cells.

Abstract Introduction: S-1 contains tegafur, which is converted to 5-fluorouracil by CYP2A6. We evaluated the association between polymorphisms of CYP2A6, ERCC1 and XRCC1 and treatment outcomes of metastatic gastric cancer (MGC) patients treated with S-1/cisplatin. Methods: Among chemonaive MGC patients (n=108) who received S-1 40 mg/m2 b.i.d. on days 1-14 and cisplatin 60 mg/m2 on day 1 of a 3-week cycle, we analyzed the wild-type allele [W] (CYP2A6*1), four CYP2A6 variants [V] that abolish (CYP2A6*4) or reduce (CYP2A6*7, *9, *10) enzyme activity, and the polymorphisms of ERCC1 [8525C>T (rs11615), 19442C>A (rs3212986)] and XRCC1 [1196G>A (rs25487)]. Results: Patients having fewer CYP2A6 variants had significantly better response rates (W/W vs W/V other than *1/*4 vs V/V or *1/*4 = 66.7% vs 58.3% vs 32.3%; P=0.008), time to progression (TTP) (median, 7.2 vs 6.1 vs 3.5 months, P=0.021), and overall survival (median, 23.2 vs 15.4 vs 12.0 months, P=0.004). ERCC1 19442C>A was also associated with response rate (C/C, 46.7% vs C/A, 55.3% vs A/A, 87.5%) (P=0.048) and TTP (median, 4.4 vs 7.6 vs 7.9 months) (P=0.012). When we classified patients according to the number of risk genotypes of CYP2A6 (V/V or 1/*4) and ERCC1 19442C>A (C/C), patients carrying two vs those carrying none showed an adjusted odds ratio of 0.113 (95% CI, 0.025-0.509) (P=0.004) for response and adjusted hazard ratios of 3.748 (95% CI, 1.900-7.393) (P=0.0001) for TTP and 2.961 (95% CI, 1.371-6.393) (P=0.006) for death.Conclusion: CYP2A6 and ERCC1 19442C>A polymorphisms are important predictors for the efficacy of S-1/cisplatin in MGC patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5450. doi:10.1158/1538-7445.AM2011-5450

Docosahexaenoic acid (DHA) has been reported to induce tumor cell death by apoptosis. However, little is known about the effects of DHA on autophagy, another complex well-programmed process characterized by the sequestration of cytoplasmic material within autophagosomes. Here, we show that DHA increased both the level of microtubule-associated protein light-chain 3 and the number of autophagic vacuoles without impairing autophagic vesicle turnover, indicating that DHA induces not only apoptosis but also autophagy. We also observed that DHA-induced autophagy was accompanied by p53 loss. Inhibition of p53 increased DHA-induced autophagy and prevention of p53 degradation significantly led to the attenuation of DHA-induced autophagy, suggesting that DHA-induced autophagy is mediated by p53. Further experiments showed that the mechanism of DHA-induced autophagy associated with p53 attenuation involved an increase in the active form of AMP-activated protein kinase and a decrease in the activity of mammalian target of rapamycin. In addition, compelling evidence for the interplay between autophagy and apoptosis induced by DHA is supported by the findings that autophagy inhibition suppressed apoptosis and further autophagy induction enhanced apoptosis in response to DHA treatment. Overall, our results demonstrate that autophagy contributes to the cytotoxicity of DHA in cancer cells harboring wild-type p53.

Recent molecular and clinical studies have shown that invasion and metastasis may occur very early in tumour development, thus emphasizing the potential importance of spesific and sensitive detection of circulating tumour cells (CTC). With the ability of refined technologies the identification of CTCs from peripheral blood is emerging as a useful tool for the detection of malignancy, monitoring disease progression and measuring response to therapy. The goal of this study was to identify optimal marker or marker combinations for detection of CTCs in the gastrointestinal malignancies using RT-PCR. Materials and Methods: To detect the presence of CTCs, we analyzed Cytokeratin 19 (CK19), Cytokeratin 20 (CK20) and Mucin 1 (MUC1) mRNA in the peripheral blood of 31 patients with gastrointestinal (gastric, stomach and colorectal) carcinoma and 30 healthy individuals. Results: In RT-PCR analysis of the peripheral blood, 77.4% (24/31), 58.06% (18/31) and 3.22% (1/31) of cancer patients were positive for MUC1, CK20 and CK19 mRNA respectively. The sensivity and specificity for any one of mRNA detected in peripheral blood is 83.3% and 66.6% respectively, with an acurracy of 59%. Conclusions: Our study suggest that MUC1 and CK20 mRNAs in the peripheral blood could be useful molecular markers for gastrointestinal tumours. Combination of these two tumour-spesific mRNA markers would increase the detection rate and may be clinically helpful in predicting the tumour presence and colorectal cancer metastasis.

BACKGROUND:Although gastric cancer with isolated para-aortic lymph node (PAN) involvement is considered an advanced disease, the clinical characteristics of it have not been comprehensively elucidated.PATIENTS AND METHODS:We reviewed the medical records of 1,277 patients received palliative chemotherapy with advanced gastric cancer according to metastatic sites: PAN-only metastasis, single organ metastasis other than PAN, and multiple organ metastasis. Time to other organ metastasis (TTOM) was determined only in PAN-only metastasis group as the time interval between initial diagnosis of recurrence or de novo metastasis and confirming distant metastasis beyond PAN area.RESULTS:The median overall survival (OS) of patients with PAN-only metastasis was significantly longer than that of patients with single organ metastasis other than PAN or multiple organ metastasis (13.8 months vs. 11.4 months vs. 8.4 months; P < 0.001). In the PAN-only metastasis group, patients with recurrent diseases showed longer TTOM beyond the PAN area (10.7 vs. 7.7 months; P = 0.037) and OS (23.8 vs. 12.8 months; P = 0.010) than those with de novo metastatic disease and it was validated by multivariate analysis.CONCLUSION:Patients with isolated PAN metastasis showed an excellent prognosis compared with patients with metastasis at other sites and it was primarily evident in patients with recurrent PAN metastasis.

We performed a retrospective study to evaluate the efficacy of cetuximab plus chemotherapy in metastatic gastric cancer (MGC) patients previously treated with chemotherapy and to investigate potential predictors of treatment efficacy in those patients.

Over 90% of human cervical carcinoma is associated with high risk human papillomavirus (HPV), and a number of biological effects that could contribute to cancer suppression by ω3-polyunsaturated fatty acids (ω3-PUFAs) have been reported. However, the anti-cancer effect of ω3-PUFAs on cervical cancer has been not known yet. In this study, we report inhibitory mechanisms of ω3-PUFAs on cell growth and invasion in cervical cancer. DHA inhibited the cell growth in a dose- and time-dependent manner. In flow cytometry analysis, cell cycle of DHA-treated HeLa cells was arrested in G2/M phase and SubG1 cells also increased. Moreover, apoptotic cell death was confirmed by TUNEL assay, the induction of PARP cleavage and down-regulation of Bcl-2. The invasiveness of cells was significantly inhibited by DHA treatment in vitro transwell assay as well. The MMP-9 and MMP-2 promoter activities were decreased after DHA treatment. Cox-2 and VEGF promoter activities were also inhibited by DHA. Furthermore, DHA decreased the levels of reporter activity of NF-κB, which is transcription factor that regulates MMPs, Cox-2 and VEGF expression. In in vivo experiments, when human papillomavirus type 16 (HPV16)-transformed mouse TC-1 cells were injected into the tail vein of Fat1 mice (Fat1 transgenic mice express a Caenorhabditis elegans ω3-desaturase converting ω6- to ω3-PUFAs endogenously.) and WT (wild type) mice, lung metastasis of TC-1 cells was dramatically inhibited in Fat1 transgenic mice compared to WT mice. Taken together, these findings provide evidence that ω3-PUFAs may inhibit metastasis as well as cell growth and invasion through suppression of MMPs/COX-2/VEGF expression by inhibition of NF-κB expression in cervical cancer cells, indicating that the utilization of ω3-PUFAs may represent a potential effective therapy for the chemoprevention and treatment of human cervical cancer. This work was supported by basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (2010-0016447 and R13-2007-020-01000-0), Korea.

BACKGROUNDThe aim of this study was to investigate the efficacy and safety of S-1/irinotecan/oxaliplatin (TIROX) in metastatic gastric cancer (MGC) and the association between treatment outcome and uridine diphosphate-glucuronosyltransferase (UGT) 1A polymorphisms.PATIENTS AND METHODSPatients with previously untreated MGC received S-1 40 mg/m(2) b.i.d. on days 1-14 and irinotecan 150 mg/m(2) plus oxaliplatin 85 mg/m(2) on day 1 every 3 weeks.RESULTSForty-four patients were enrolled. In intent-to-treat analysis, the objective response rate was 75%, including the complete response (CR) rate of 14%. The median time to progression and overall survival was 10.2 and 17.6 months, respectively. Ten (26%) of the 39 patients with primary gastric tumor showed biopsy-confirmed gastric CR. Grade 3/4 neutropenia developed in 66% of patients and grade 3 febrile neutropenia in 16%. The most common grade 3 nonhematologic toxic effects were abdominal pain (18%), anorexia (16%), and diarrhea (14%). UGT1A polymorphisms were associated with significantly higher incidence of grade 4 leukopenia (UGT1A1*6), neutropenia (UGT1A1*6, UGT1A6*2, and UGT1A7*3), grade 3/4 febrile neutropenia (UGT1A1*6), and grade 3 abdominal pain (UGT1A1*6).CONCLUSIONSThe TIROX regimen induced marked tumor reduction and promising survival with a manageable toxicity profile in MGC patients. UGT1A genotype may be predictive of TIROX toxicity.