Jeong-Oh Kim

LY294002 may overcome 5-FU resistance via down-regulation of activated p-AKT in Epstein-Barr virus-positive gastric cancer cells

BackgroundAs EBV-associated gastric cancer has unique features that are different from EBV (-) gastric cancer, EBV is considered to have a key role in gastric carcinogenesis. It has been reported that viral latent membrane protein 2A (LMP2A) in EBV-transformed tumor cells activates the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which provides a survival signal and chemo-resistance to cytotoxic anti-cancer drugs. This study was to evaluate anti-proliferative effect and cell cycle change when 5-FU and LY294002 (LY), a selective inhibitor of PI3K, were treated separately or combined with different schedules in EBV positive gastric cancer cell line, SNU-719.MethodsAfter single treatment and sequential combination of 5-FU and LY, cytotoxic activity was measured by MTS assay. When 5-FU and LY were treated in single and sequential combinations, the expression of p-AKT, p-NFkB, p-p53 and bcl-2 was observed on different concentrations by Western blot analysis. We also investigated the effect on apoptosis and cell cycle distribution using flow cytometry. The LMP2A siRNA inhibition was done to confirm the reversal of decreased 5-FU activity and p-AKT.ResultsWhen 5-FU was sequentially combined with LY, the combination index (CI) value indicated synergistic anti-proliferative effect. The expression of p-AKT and p-NFκB was upregulated by 5-FU alone but sequential treatment of 5-FU and LY decreased the expression of both p-AKT and p-NFκB. When 5-FU was combined with LY, G0/G1 and sub G1 cell population (%) increased. When 5-FU was added to the cells transfected with LMP2A siRNA, its anti-proliferative effect increased and the expression of p-AKT decreased. In sequential combination of 5-FU and LY, the expression of p-p53 was increased and bcl-2 expression was diminished compared to 5-FU alone.ConclusionThese data suggest that sequential combination of 5-FU and LY induce synergistic cytotoxicity and overcome intrinsic and acquired resistance of 5-FU via downregulation of activated p-AKT and mitochondria-dependent apoptosis in EBV gastric cancer cell line, SNU-719.

Proposal of pharmacogenetics-based warfarin dosing algorithm in Korean patients.

Warfarin is a commonly prescribed anticoagulant drug for the prevention of thromboembolic disorders. We investigated the contribution of genetic variations of four genes and clinical factors to warfarin dose requirement and provided a warfarin-dosing algorithm based on genetic and clinical variables in Korean patients. We recruited 564 Korean patients on stable anticoagulation. Single nucleotide polymorphisms (SNPs) for the VKORC1, CYP2C9, CYP4F2 and GGCX were analyzed. Using multiple regression analysis, we developed a model to predict the warfarin requirement. The SNPs of VKORC1, CYP2C9, CYP4F2 and GGCX showed significant correlation with warfarin dose. Patients with the 3730AA genotype received significantly higher doses of warfarin than those with the 3730GG (P=0.0001). For CYP2C9, the highest maintenance dose was observed in the patients with wild-type genotype compared with the variant allele carriers (P<0.0001). The multiple regression model including age, gender, body surface area (BSA), international normalized ratio (INR) and four genetic polymorphisms accounted for 35% of total variations in warfarin dose (R2=0.3499; P<0.0001). This study shows that age, gender, BSA, INR and VKORC1, CYP2C9 and CYP4F2 polymorphism affect warfarin dose requirements in Koreans. Translation of this knowledge into clinical guidelines for warfarin prescription may contribute to improve the efficacy and safety of warfarin treatment for Korean patients.

A CDK4/6 inhibitor enhances cytotoxicity of paclitaxel in lung adenocarcinoma cells harboring mutant KRAS as well as wild-type KRAS

The KRAS gain-of-function mutation confers intrinsic resistance to targeted anti-cancer drugs and cytotoxic chemotherapeutic agents, ultimately leading to treatment failure. KRAS mutation frequency in lung adenocarcinoma is ~15–30%. Novel therapeutic strategies should be developed to improve clinical outcomes in these cases. Deregulation of the p16/cyclin-dependent kinase (CDK) 4/retinoblastoma (Rb) pathway is frequently observed in various cancers and it represents an attractive therapeutic target. We compared the anti-tumor efficacy of genetically knocked-down CDK4 and a pharmacological inhibitor of CDK4/6, CINK4, in KRAS mutation-positive lung adenocarcinoma cells. We also investigated changes in anti-proliferative activity and downstream molecules with these treatments in combination with paclitaxel. CDK4 short interfering RNA (siRNA) significantly increased paclitaxel sensitivity in KRAS mutation-positive H23 cells. CINK4 demonstrated concentration- and time-dependent anti-proliferative activity in 5 adenocarcinoma lines. CINK4 induced G1 arrest by downregulating the p16/cyclin D1/Rb pathway, resulting in apoptotic induction via increased expression of cleaved caspase3, cleaved PARP and Bax. Combined CINK4 and paclitaxel produced synergistic anti-proliferative activity and increased apoptosis through reduced cyclin D1 and Bcl-2 in KRAS mutation-positive cancer cells. These data suggest CDK4 is a promising target for development of anti-cancer drugs and CINK4 combined with paclitaxel may be an effective therapeutic strategy for enhancing anti-tumor efficacy in KRAS mutation-positive lung adenocarcinoma.

Synergistic antitumor efficacy of sequentially combined paclitaxel with sorafenib in vitro and in vivo NSCLC models harboring KRAS or BRAF mutations.

Studies on non-small cell lung cancer (NSCLC) patients with KRAS or BRAF mutations are urgently needed to improve clinical outcomes. We evaluated the cytotoxicities of paclitaxel and sorafenib alone and in combination in NSCLC cell lines with KRAS or BRAF mutations and investigated the mechanism of the interaction between the drugs. We found synergistic antitumor efficacy with paclitaxel followed by sorafenib in in vitro and in vivo models of NSCLC. And, we determined that downregulation of the phosphorylated ERK and Rb, and Mcl-1 plays a critical role in the synergistic activity of the drugs. Further clinical trials are needed to verify the antitumor efficacy of this combination.

Genetic Variations of Drug Transporters Can Influence on Drug Response in Patients Treated with Docetaxel Chemotherapy

Purpose Dose-limiting toxicities of docetaxel are widely considered to be neutropenia, anemia, skin toxicity, and nausea. One of the factors that limit the use of docetaxel is its unpredictability of inter-individual variation in toxicity. Materials and Methods In order to identify the genetic factors that affect the risk of docetaxel-induced toxicities, we recruited patients who received docetaxel chemotherapy. We genotyped 92 patients with single-nucleotide polymorphisms (SNPs) in 5 genes: CYP3A4 (CYP3A4*1B, CYP3A4*18, and CYP3A4*3), CYP3A5 (CYP3A5*2 and CYP3A5*3), ABCB1 (C1236T, G2677G/T, and C3435T), SLCO1B3 (rs11045585), and ABCC2 (rs12762549). Results Out of 92 patients, 70 had grade 3 or 4 neutropenia; 4 had grade 1 or 2; and 18 had no toxicity (76.1%, 4.3%, and 19.6%, respectively). The findings of the SNP analysis showed that patients with TT genotype of ABCB1 3435C>T polymorphism showed significantly higher risk of neutropenia and anemia (p=0.029 and p=0.044, respectively). There were significant associations between docetaxel-induced leucopenia and 2677G/T of ABCB1 and rs12762549 of ABCC2 (p=0.025 and p=0.028, respectively). In a multivariate analysis, we observed that patients carrying 2677G>T in ABCB1might be associated with higher risk of chemo-resistance when treated with docetaxel (odds ratio [OR], 6.48; confidence interval, 1.92 to 21.94; p=0.003). In a subgroup analysis of non-small cell lung cancer patients, a significant association of tumor response with G2677T/A (OR, 4.54) in ABCB1 and SLCO1B3 (OR, 9.44) was observed. Conclusion Our data suggest that ABCB1 (2677G/T) and SLCO1B3 (rs11055585) might be major genetic predictors of docetaxel-related toxicities in patients receiving docetaxel chemotherapy.

Molecular genetic characterization of p53 mutated oropharyngeal squamous cell carcinoma cells transformed with human papillomavirus E6 and E7 oncogenes

Patients with HPV-positive oropharyngeal cancer show better tumor response to radiation or chemotherapy than patients with HPV-negative cancer. HPV oncoprotein E6 binds and degrades a typically wild-type p53 protein product. However, HPV16 infection and p53 mutation infrequently coexist in a subset of HNSCCs. The purpose of this study was to investigate the mechanisms through which tumor biology and molecular genetic mechanisms change when two HPV-negative, p53-mutated oropharyngeal cell lines (YD8, non-disruptive p53 mutation; YD10B, disruptive p53 mutation) derived from patients with a history of heavy smoking are transfected with HPV E6 and E7 oncogenes in vitro. Transfection with HPV E6 and E7 oncogenes in YD8, reduced the abundance of proteins encoded by tumor suppressor genes, such as p-p53 and p-Rb. Cell proliferative activity was increased in the cells transfected with E6E7 compared to cells transfected with vector alone (P=0.09), whereas the invasiveness of E6E7-transfected cells was significantly reduced (P=0.02). cDNA microarray of the transfected cells with E6E7 showed significant changes in mRNA expression in several signaling pathways, including focal adhesion, JAK-STAT signaling pathway, cell cycle and p53 signaling pathway. Regarding the qPCR array for the p53 signaling pathway, the mRNA expression of STAT1 was remarkably upregulated by 6.47-fold (P<0.05); in contrast, IGF-1R was significantly downregulated by 2.40-fold in the YD8-vector compared toYD8-E6E7 (P<0.01). Finally, data collected from these two array experiments enabled us to select two genes, STAT1 and IGF-1R, for further study. In immunohistochemical study, nuclear STAT1 expression was slightly higher in HPV-positive compared to HPV-negative oropharyngeal tumors (P=0.18); however, cytoplasmic STAT1 was significantly lower in HPV-positive cases (P=0.03). IGF-1R expression levels were remarkably lower in HPV-positive compared to HPV-negative cases (P=0.01). Our data suggest that upregulated STAT1 and interferon signals by HPV16 E6 and E7 genes may play a major role in the relatively favorable prognosis for HPV-positive oropharyngeal squamous cell carcinoma cases with non-disruptive p53 mutations.

The prognostic role of tissue and serum MMP-1 and TIMP-1 expression in patients with non-small cell lung cancer.

PURPOSE Matrix metalloproteinase (MMP) and tissue inhibitor of matrix metalloproteinase (TIMP) play an important role in tumor invasion and progression. The aim of this study was to evaluate the prognostic role of MMP-1 and TIMP-1 in non-small cell lung cancer (NSCLC). To find out a potential serum biomarker, tissue and serum levels were investigated together. PATIENTS AND METHODS For 85 surgically resected NSCLC patients who had pre-operative serum samplings, MMP-1 and TIMP-1 expression were investigated using immunohistochemistry in tumor tissue and ELISA in serum. Tumor cells and surrounding stromal cells were assessed separately. RESULTS Higher expression of MMP-1 in tumor cells comparing to stromal cells was related to male gender (P=0.006), ever smoker (P=0.004), and pooly differentiated tumor (P=0.043). For TIMP-1, adenocarcinoma showed higher tumor cell expression, while squamous cell carcinoma showed higher stromal expression (P=0.007). Patients with high carcinoembryonic antigen (CEA) level, the presence of vascular invasion, recurrence or death showed higher serum MMP-1 level. There was no correlation between the tissue and serum levels of MMP-1 and TIMP-1. A tumor/stroma TIMP-1 intensity ratio ≥1 was strongly associated with early recurrence in multivariate analysis (hazard ratio=280.55, 95% confidence intervals; 11.12-7080.45; P=0.001). High serum MMP-1 (≥3,500pg/ml) showed a trend for short overall survival (P=0.080). When serum MMP-1 was combined with CEA level or presence of vascular invasion, its prognostic implication was statistically significant (P=0.045 and P=0.015, respectively). CONCLUSION The tumor/stroma TIMP-1 intensity ratio in tissue is useful to predict tumor recurrence. Serum MMP-1 level showed a possibility as a prognostic biomarker.

Long-term outcome of tamsulosin for patients with lower urinary tract symptoms according to the treatment response defined by lower urinary tract symptom outcomes score

Aims:  To evaluate long‐term outcome of tamsuolsin 0.2 mg for benign prostatic hyperplasia (BPH) patients using a new subjective assessment of patient‐reported outcomes and the lower urinary tract symptoms (LUTS) outcome score (LOS) over a 48‐week period.

Prognostic role of beclin-1 in locally advanced non-small cell lung cancer in patients receiving docetaxel-platinum induction chemotherapy

Background/Aims The outcome of local treatment for advanced non-small cell lung cancer (NSCLC) remains poor, with therapies such as induction chemotherapy (IC) yielding conflicting results. This study aimed to assess the clinicopathologic and prognostic significance of the excision repair cross-complementation group 1 (ERCC1), beclin-1, and glucose-regulated protein of molecular mass 78 (GRP78) in patients with locally advanced NSCLC receiving docetaxel-platinum IC, along with efficacy and safety. Methods This is a retrospective observational cohort study. We reviewed medical records of 31 NSCLC patients receiving docetaxel-platinum IC, and conducted immunohistochemical staining of ERCC1, beclin-1, and GRP78. Results Response rate was 67.8% with 10.7 months of median relapse-free survival (RFS) and 23.1 months of median overall survival (OS), and no treatment-related death was reported. High expression of ERCC1, beclin-1, and GRP78 was identified in 67.7%, 87.1%, and 67.7%, respectively. Expression of ERCC1 and GRP78 did not reveal statistical significance in survival, whereas high beclin-1 expression revealed longer OS (7.6 months vs. 23.2 months; log-rank p = 0.024). In multivariate analysis, histologic differentiation (hazard ratio [HR], 3.48; p < 0.001), stage (HR, 8.5; p = 0.024), and adjuvant treatment (HR, 16.1; p = 0.001) were related to RFS, and in OS, stage (HR, 5.4; p = 0.037), adjuvant treatment (HR, 8.6; p = 0.004), and beclin-1 expression (HR, 8.2; p = 0.011) were identified as significant prognostic factors. Conclusions Our findings suggest that high beclin-1 expression predicts longer survival in locally advanced NSCLC and docetaxel-platinum IC is a treatment option that deserves consideration.

Abstract 2832: Synergistic effect of combined cdk4/6 inhibitor with docetaxel in lung cancer cell lines harboring KRAS mutations

Background & Purpose LY2835219(LY), a novel CDK4/6 inhibitor, inhibits phosphorylation of RB and E2F activation, thereby arresting the cell cycle in the G1 phase and suppressing the cell proliferation and cell division. Docetaxel(DTX) is a cytotoxic anti-cancer drug, which inhibits mitotic cell division, thus induces G2/M arrest and apoptosis of various cancer cells. In present study, we evaluated the activities of CDK4/6 inhibitor alone or combined with docetaxel on the anti-proliferation, cell cycle and apoptosis in lung cancer cell lines harboring KRAS mutations. Methods We measured the anti-proliferative activities of LY or DTX single and their combinations (DTX+LY 72h and DTX 24h->LY 48h) on cell proliferation in A549(G12S) and H727(G12V) cells using CCK-8 asssy. We evaluated the expression of CDK2, CDK4, cPARP and caspase-3 by Western blot. The cell cycle distribution and apoptosis in subG1 phase were analyzed by flow cytometry. Results The IC 50 values of the LY and DTX alone were 0.4 ± 0.2 uM and 0.9 ± 0.2 nM in A549 cells and 2.0 ± 0.7 uM and 3.1 ± 0.3 nM in H727 cells, respectively. The CI (Combination index) of the DTX->LY sequential and the DTX+LY simultaneous treatments were 0.8 and 0.9 (CI LY showed decreased cell viability by 60% at very low concentration of DTX (3.0e −5 nM), but DTX+LY showed significantly decreased cell viability by 40% at higher concentration of DTX (IC50 values can not be measured). In A549 cells, after DTX treatment for 72h, the cell population in G2/M phase increased by 54.5% relative to control (24.6%). With LY alone, the fraction of A549 cells in G0/G1 phase increased compared to control (78.4% vs. 49.5%). In case of DTX+LY combination, the G2/M fraction of A549 cells significantly increased by 33% vs 24.6% in a dose-dependent manner. Meanwhile, in DTX->LY treatment, cell fractions in G2/M were increased (44.5% vs 24.6%), especially those in G0/G1 phases were remarkably reduced (14.7% vs 49.5%). In addition, the subG1 fraction was accumulated in response to individual drug treatments. In case of DTX single treatment, the subG1 fractions of both A549 and H727 cells increased in a dose-dependent manner (0.7% vs. 17.4% and 2.5% vs. 28.1%, respectively). We were not able to observe the change of subG1 fraction in DTX+LY combination treatment in A549 cells. However, in DTX->LY sequential treatment, the subG1 fraction increased in a dose-dependent manner by relative to control (23.3% vs 10.9%). The expression of c-PARP and caspase-3 was increased by the DTX alone and two different combination schedule and CDK2 and CDK4 expressions were decreased by LY alone and DTX->LY sequential treatment. Conclusions Taken together, our results suggest that DTX->LY sequential treatment has enhanced antitumor efficacy with synergistic interaction in lung cancer cell lines harboring KRAS mutations. Citation Format: Kyoung Hwa Son, Jung-Young Shin, Jeong-Oh Kim, JinHyoung Kang. Synergistic effect of combined cdk4/6 inhibitor with docetaxel in lung cancer cell lines harboring KRAS mutations. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2832.