Yousheng Wu

Leukocyte telomere length: a novel biomarker to predict the prognosis of glioma patients

AbstractPurpose Epidemiological studies have demonstrated that leukocyte telomere length is associated with the developing risk of various malignancies, including glioma. However, its prognostic value in glioma patients has never been investigated.MethodsRelative telomere length (RTL) of peripheral blood leukocytes from 301 glioma patients were examined using a real-time PCR-based method. Kaplan–Meier curves and Cox proportional hazards regression model were used to assess the association of RTL with clinical outcomes of patients. To explore the potential mechanism, the immune phenotype of peripheral blood mononuclear cells (PBMCs) and concentrations of several cytokines from another 20 glioma patients were detected by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. The relationship between RTL and immunological characteristics of PBMCs were further analyzed.ResultsPatients with short RTL showed both poorer overall survival (OS) and progression-free survival (PFS) than those with long RTL. Multivariate Cox regression analysis demonstrated that RTL was an independent prognostic factor for both OS and PFS in glioma patients. Moreover, the effects of RTL on the prognosis of patients exhibited a dose-dependent manner. Stratified analysis showed that the prognostic value of RTL was not affected by host characteristics except for age. In addition, flow cytometry and ELISA analyses indicated that there was no significant association between RTL and frequency of different immune cell subsets or plasma cytokine concentrations.ConclusionsOur study for the first time demonstrates that leukocyte RTL is an independent prognostic marker for glioma patients. The potential mechanism needs further investigation.

Transarterial chemoembolization aggravated peritumoral fibrosis via hypoxia-inducible factor-1α dependent pathway in hepatocellular carcinoma.

It was commonly accepted that chemotherapeutic cytotoxicity was the main cause for hepatic failure in hepatocellular carcinoma patients after repeated transarterial chemoembolization (TACE). However, the effect of embolization‐induced hypoxia on liver cirrhosis has rarely been concerned.

Genetic variations in monocarboxylate transporter genes as predictors of clinical outcomes in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is characterized by poor prognosis and only a few molecular markers may be potentially used to predict clinical outcomes. Previous studies have demonstrated that monocarboxylate transporters (MCTs) play important roles in the development and progression of many cancers. The purpose of this study was to assess the effects of single nucleotide polymorphisms (SNPs) of MCT genes on prognosis of NSCLC patients in Chinese Han population. Nine functional SNPs in MCT1, MCT2, and MCT4 genes were selected and genotyped using Sequenom iPLEX genotyping system in 500 Chinese NSCLC patients receiving surgery. Multivariate Cox proportional hazards model and Kaplan–Meier curve were used for the prognostic analysis. TT genotype of SNP rs1049434 (MCT1) was significantly associated with better overall survival (OS) (HR = 0.56, P = 0.026) and recurrence-free survival (RFS) (HR = 0.57, P = 0.016) of NSCLC patients. TT genotype of another SNP rs995343 (MCT2) exhibited an association with worse RFS of NSCLC patients (HR = 1.46, P = 0.039). Unfavorable genotypes of SNP rs1049434 and rs995343 showed a significant cumulative effect on OS and RFS of NSCLC patients. Moreover, we found that patients carrying AA+AT genotypes of rs1049434 showed significant OS and RFS benefits from adjuvant chemotherapy, but those with TT genotype did not. Our findings suggest that SNPs in MCT1 and MCT2 genes may affect clinical outcomes and can be used to predict the response to adjuvant chemotherapy in NSCLC patients who received surgical treatment once validated in future study.

Genetic variants in genes of tricarboxylic acid cycle key enzymes are associated with prognosis of patients with non-small cell lung cancer.

INTRODUCTION Non-small cell lung cancer (NSCLC) is characterized by poor prognosis and only a few molecular markers may be potentially used to predict the outcome. Metabolic reprogramming is a hallmark of cancer, including the alterations of tricarboxylic acid (TCA) cycle key enzymes. However, the significance of single nucleotide polymorphisms (SNPs) in genes encoding these key enzymes has not been investigated in NSCLC. PATIENTS AND METHODS In this study, we genotyped 18 potentially functional SNPs in 7 genes belonging to 3 TCA cycle enzyme families (SDH, FH and IDH) using Sequenom iPLEX genotyping system in a cohort of 500 NSCLC patients. Multivariate Cox proportional hazards model and Kaplan-Meier curve were used for the survival analysis. RESULTS Our results showed that SDHC gene: SNP rs12064957, IDH2 gene: SNP rs11540478 and FH gene: SNP rs1414493 were associated with overall survival (OS) and SDHA gene: SNP rs13173911, IDH2 gene: SNP rs4932158 were associated with recurrence-free survival (RFS) of NSCLC patients. Unfavorable genotypes of these SNPs showed a significant cumulative effect on OS and RFS of NSCLC patients (both P<0.001). Furthermore, survival tree analysis indicated that FH: rs1414493 was the primary risk factor contributing to OS of NSCLC patients and the IDH2: rs4932158 was the primary risk factor contributing to RFS of NSCLC patients. CONCLUSION Our data suggest that SNPs in TCA cycle key enzyme genes may serve as potential biomarkers to predict the outcomes of NSCLC. Further studies with different ethnicities are needed to validate our findings and generalize their clinical utility.

Genetic Variants in ASCT2 Gene are Associated with the Prognosis of Transarterial Chemoembolisation-Treated Early-Stage Hepatocelluar Carcinoma

BACKGROUND Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide. Transarterial chemoembolisation (TACE) is the standardized therapy for intermediate stage HCC. However, the prognosis for HCC patients treated by TACE greatly varies. Thus, there is a critical need for finding biomarkers to predict the prognosis of HCC patients. The amino acid transporter-2 (ASCT2) is involved in tumorigenesis and progression of many malignancies. This study aimed to evaluate the predictive role of two single nuclear polymorphisms (SNPs, rs3826793 and rs2070246) in the ASCT2 gene in HCC patients treated by TACE. MATERIALS AND METHODS Two functional SNPs (rs3826793 and rs2070246) in the ASCT2 gene were selected and genotyped using the Sequenom iPLEX genotyping system in a cohort of 448 unresectable Chinese HCC patients treated by TACE. Univariate and multivariate Cox proportional hazards models and Kaplan-Meier curves were used for the prognosis analyses. RESULTS There was no significant association between two SNPs (rs3826793 and rs2070246) in the ASCT2 gene and overall survival of TACE treated HCC patients. However, we demonstrated that patients with early stage HCC carrying T genotype in rs2070246 showed better OS than those carrying CC genotype (P=0.023). CONCLUSIONS We demonstrated that patients with early stage HCC carrying T genotype in rs2070246 showed better OS than those carrying CC genotype.

Polymorphisms in genes of the de novo lipogenesis pathway and overall survival of hepatocellular carcinoma patients undergoing transarterial chemoembolization.

Aberrant expression of genes in de novo lipogenesis (DNL) pathway were associated with various cancers, including hepatocellular carcinoma (HCC). Single nucleotide polymorphisms (SNPs) of DNL genes have been reported to be associated with prognosis of some malignancies. However, the effects of SNPs in DNL genes on overall survival of HCC patients receiving transarterial chemoembolization (TACE) treatment are still unknown. In present study, nine SNPs in three genes (ACLY, ACACA and FASN) in DNL pathway were genotyped using the Sequenom iPLEX genotyping system in a hospital-based cohort with 419 HCC patients treated with TACE, and their associations with HCC overall survival were evaluated by Cox proportional hazard regression analysis under three genetic models (additive, dominant and recessive). Although we did not find any significant results in total analysis (all p>0.05), our stratified data showed that SNP rs9912300 in ACLY gene was significantly associated with overall survival of HCC patients with lower AFP level and SNP rs11871275 in ACACA gene was significantly associated with overall survival of HCC patients with higher AFP level. We further identified the significant interactions between AFP level and SNP rs9912300 or rs11871275 in the joint analysis. Conclusively, our data suggest that genetic variations in genes of DNL pathway may be a potential biomarker for predicting clinical outcome of HCC patients treated with TACE.

Polymorphisms in Genes of Tricarboxylic Acid Cycle Key Enzymes Are Associated with Early Recurrence of Hepatocellular Carcinoma.

Alterations of activity and expression in tricarboxylic acid (TCA) cycle key enzymes have been indicated in several malignancies, including hepatocellular carcinoma (HCC). They play an important role in the progression of cancer. However, the impact of single nucleotide polymorphisms (SNPs) in genes encoding these key enzymes on the recurrence of HCC has not been investigated. In this study, we genotyped 17 SNPs in genes encoding TCA cycle key enzymes and analyzed their association with recurrence-free survival (RFS) in a cohort of 492 Chinese HCC patients by Cox proportional hazard model and survival tree analysis. We identified 7 SNPs in SDHC, SDHD, FH, and IDH2 genes to be significantly associated with the RFS of HCC patients. Moreover, all these SNPs were associated with the early recurrence (within 2 years after surgery) risk of diseases. Cumulative effect analysis showed that these SNPs exhibited a dose-dependent effect on the overall and early recurrence. Further stratified analysis suggested that number of risk genotypes modified the protective effect on HCC recurrence conferred by transcatheter arterial chemoembolization treatment. Finally, the survival tree analysis revealed that SNP rs10789859 in SDHD gene was the primary factor contributing to HCC recurrence in our population. To the best of our knowledge, we for the first time observed the association between SNPs in genes encoding TCA cycle key enzymes and HCC recurrence risk. Further observational and functional studies are needed to validate our findings and generalize its clinical usage.

Low expression of CD112 is associated with poor overall survival in patients with hepatocellular carcinoma

CD112 as an important ligand of CD226 can stimulate the natural killer (NK) cell-mediated target cell lysis. Previous studies have reported that CD112 is involved in cancer initiation and progression. However, its expression and clinical significance in hepatocellular carcinoma (HCC) have never been investigated. In this study, we used immunohistochemistry to examine CD112 expression in cancer and pericancer tissues from 159 HCC cases. Western blot and immunofluorescence were used to detect CD112 expression in HCC cell lines. χ(2) Test was used to assess the association of CD112 expression with clinicopathological characteristics, whereas Kaplan-Meier survival function and Cox proportional hazards regression model were used to explore the association between CD112 expression and clinical outcome of patients with HCC. Overall, CD112 expression was significantly reduced in HCC tissues when compared with adjacent pericancer liver tissues (P < .001). Western blot and immunofluorescence analyses showed that most HCC cell lines had low CD112 expression level. Furthermore, low CD112 expression was significantly associated with high serum α-fetoprotein level (P = .004) in patients with HCC. Kaplan-Meier analysis showed that patients with low CD112 expression had poorer postsurgery overall survival than those with high CD112 expression (log-rank P = .045). In conclusion, our findings demonstrate that the down-regulation of CD112 may be an important mechanism through which HCC cells evade the natural killer cell-mediated immunosurveillance, and thus, CD112 may be a useful biomarker to assess the immunologic niche of HCC.

Increased mtDNA copy number promotes cancer progression by enhancing mitochondrial oxidative phosphorylation in microsatellite-stable colorectal cancer

Colorectal cancer is one of the leading causes of cancer death worldwide. According to global genomic status, colorectal cancer can be classified into two main types: microsatellite-stable and microsatellite-instable tumors. Moreover, the two subtypes also exhibit different responses to chemotherapeutic agents through distinctive molecular mechanisms. Recently, mitochondrial DNA depletion has been shown to induce apoptotic resistance in microsatellite-instable colorectal cancer. However, the effects of altered mitochondrial DNA copy number on the progression of microsatellite-stable colorectal cancer, which accounts for the majority of colorectal cancer, remain unclear. In this study, we systematically investigated the functional role of altered mitochondrial DNA copy number in the survival and metastasis of microsatellite-stable colorectal cancer cells. Moreover, the underlying molecular mechanisms were also explored. Our results demonstrated that increased mitochondrial DNA copy number by forced mitochondrial transcription factor A expression significantly facilitated cell proliferation and inhibited apoptosis of microsatellite-stable colorectal cancer cells both in vitro and in vivo. Moreover, we demonstrated that increased mitochondrial DNA copy number enhanced the metastasis of microsatellite-stable colorectal cancer cells. Mechanistically, the survival advantage conferred by increased mitochondrial DNA copy number was caused in large part by elevated mitochondrial oxidative phosphorylation. Furthermore, treatment with oligomycin significantly suppressed the survival and metastasis of microsatellite-stable colorectal cancer cells with increased mitochondrial DNA copy number. Our study provides evidence supporting a possible tumor-promoting role for mitochondrial DNA and uncovers the underlying mechanism, which suggests a potential novel therapeutic target for microsatellite-stable colorectal cancer.Bowel cancer: Mitochondrial DNA fuels progressionAn increase in mitochondrial DNA (mtDNA) in microsatellite stable colorectal cancer (MSSCRC) cells stimulates cell proliferation and prevents cell death. MtDNA copy number is regulated by mitochondrial transcription factor A and both increases and decreases in mtDNA levels have been associated with different types of cancer. A study led by Qichao Huang and Xianli He at the Fourth Military Medical University, China, investigated the effects of altering mtDNA levels in MSSCRC cells on tumor progression in mice. They found that high levels of mtDNA promoted MSSCRC cell survival and metastasis by stimulating mitochondrial oxidative phosphorylation and energy production. Conversely, mtDNA depletion or treatment with the mitochondrial toxin oligomycin reduced the survival and metastasis of MSSCRC cells. These findings suggest that reducing mtDNA copy number could be a useful therapeutic strategy for MSSCRC.

TNFα induces Ca2+ influx to accelerate extrinsic apoptosis in hepatocellular carcinoma cells

BackgroundTumor necrosis factor-α has been proven an effective anticancer agent in preclinical studies. However, the translation of TNFα from research to clinic has been blocked by significant systemic toxicity and limited efficacy at maximal tolerated dose, which need urgently to be solved.MethodsThe level of cytosolic Ca2+ was assessed by Fura-2 in HCC cells. After changing cytosolic Ca2+ level by using agonists or inhibitors, cell apoptosis was detected by flow cytometry. We also detected the effect of ionomycin or parvalbumin on the anti-tumor activity of TNFα in a mice model. Lastly, we studied the roles of cytosolic Ca2+ in the mitochondrial-dependent intrinsic apoptosis pathway.ResultsHere, we demonstrated that TNFα induced extracellular Ca2+ influx into cytoplasm through transient receptor potential channel in HCC cells. Both cytosolic Ca2+ scavenger and Ca2+-binding protein PV effectively desensitized hepatocellular carcinoma cells to TNFα, whereas combination ionomycin or 1,4,5-inositol triphosphate significantly sensitized HCC cells to TNFα, indicating that the increased level of cytosolic Ca2+ was positively correlated with the TNFα-induced cell apoptosis in vitro. In a nude mice xenograft model, our data revealed that TNFα combined with ionomycin remarkably synergized the anti-tumor effect of TNFα. Furthermore, we found that TNFα-mediated extracellular Ca2+ influx accelerated TNFα-induced extrinsic apoptosis through activating calpain/IAP/caspase3 pathway.ConclusionsOur study provides the evidence supporting a novel mechanism by which TNFα induces extracellular Ca2+ influx to enhance cell apoptosis and suggests that increasing the level of cytosolic Ca2+ might be an alternative strategy to improve the pro-apoptotic activity of TNFα in HCC cells, although suitable chemical or biological reagents need to be further tested.