Potential of electron transfer and its application in dictating routes of biochemical processes associated with metabolic reprogramming / 医学前沿

Metabolic reprogramming, such as abnormal utilization of glucose, addiction to glutamine, and increased de-novo lipid synthesis, extensively occurs in proliferating cancer cells, but the underneath rationale has remained to be elucidated. Based on the concept of the degree of reduction of a compound, we have recently proposed a calculation termed as potential of electron transfer (PET), which is used to characterize the degree of electron redistribution coupled with metabolic transformations. When this calculation is combined with the assumed model of electron balance in a cellular context, the enforced selective reprogramming could be predicted by examining the net changes of the PET values associated with the biochemical pathways in anaerobic metabolism. Some interesting properties of PET in cancer cells were also discussed, and the model was extended to uncover the chemical nature underlying aerobic glycolysis that essentially results from energy requirement and electron balance. Enabling electron transfer could drive metabolic reprogramming in cancer metabolism. Therefore, the concept and model established on electron transfer could guide the treatment strategies of tumors and future studies on cellular metabolism.

miR-143 suppresses the proliferation and migration of SGC7901 gastric cancer cells / 中国肿瘤临床

Objective:To investigate the role and mechanism of miR-143 in the proliferation and migration of gastric cancer (GC) cells. Methods:Western blot was performed to detect the expression level of avian erythroblastosis oncogene B-3 (ERBB3) in GC tissues, paired non-cancerous tissues, and SGC7901 GC cells. RT-qPCR was conducted to determine the mRNA and miR-143 of ERBB3 quantita-tively. Bioinformatics tools were used to predict the target gene of miR-143. Luciferase reporter assay was carried out to confirm the predicted target gene. Transwell and EdU assays were applied to observe the migration and proliferation of SGC7901 GC cells transfect-ed with miR-143 mimics/inhibitor/NC mimics/inhibitor. Results:Compared with the expression levels of ERBB3 and miR-143 in the paired non-cancerous tissues, the expression level of ERBB3 was upregulated and the expression level of miR-143 was downregulated in GC tissues. In the prediction of the potential target gene, miR-143 could bind to a specific sequence of the 3′-untranslated regions (UTR) of the mRNA of ERBB3. This finding was supported by luciferase reporter assay results. In vitro, ERBB3 protein expression and cell migration and proliferation were suppressed significantly in the SGC7901 cells transfected with miR-143 mimics. By contrast, these processes were remarkably enhanced when the cells were transfected with miR-143 inhibitor. Conclusion:miR-143 can suppress the migration and proliferation of GC cells by downregulating the expression of ERBB3.

Onco-miR-24 regulates cell growth and apoptosis by targeting BCL2L11 in gastric cancer

Gastric cancer is one of the most common malignancies worldwide; however, the molecular mechanism in tumorigenesis still needs exploration. BCL2L11 belongs to the BCL-2 family, and acts as a central regulator of the intrinsic apoptotic cascade and mediates cell apoptosis. Although miRNAs have been reported to be involved in each stage of cancer development, the role of miR-24 in GC has not been reported yet. In the present study, miR-24 was found to be up-regulated while the expression of BCL2L11 was inhibited in tumor tissues of GC. Studies from both in vitro and in vivo shown that miR-24 regulates BCL2L11 expression by directly binding with 3'UTR of mRNA, thus promoting cell growth, migration while inhibiting cell apoptosis. Therefore, miR-24 is a novel onco-miRNA that can be potential drug targets for future clinical use.

A study of radiosensitizing effect of PKM2 silencing in lung adenocarcinoma cells and xenografts / 中华放射肿瘤学杂志

Objective To investigate the impacts of pyruvate kinase M2 isoform (PKM2) silencing on the radiosensitivity of lung adenocarcinoma cell line (A549 cells) and the radiation synergy of xenografts, and to explore their mechanisms. Methods Plasmid pshRNA?PKM2 for interference with PKM2 expression was transfected into A549 cells, and empty vector?transfected cells and untransfected cells were set as con?trols. The silencing efficiency of pshRNA?PKM2 and the expression level of microtubule?associated protein 1 light chain 3(LC3) were measured by Western blot assay. The radiosensitizing effects in A549 cells and xen?ografts after PKM2 silencing were determined by colony?forming assay and xenografts growth curves. Autoph?agy formation in A549 cells and xenografts was analyzed by transmission electron microscopy, and the ex?pression level of PKM2 in xenografts was measured by immunohistochemistry. Comparison between groups was made by Student′s t?test, and the body weights of nude mice and xenograft volumes were subjected to a?nalysis of variance for continuous variables. Results Stable A549 cell lines transfected with pshRNA?PKM2 were successfully produced. Transfection with pshRNA?PKM2 significantly down?regulated PKM2 expression in A549 cells and xenografts (P= 0?? 001;P= 0?? 000). The sensitizer enhancement ratios for A549 cells and xenografts were 1?? 47 and 2?? 00, respectively. Interference with PKM2 expression enhanced radiation?in duced autophagy formation and significantly increased the ratio of LC 3 ? II / I ( P= 0.000 1 ) . Conclusions Silencing of PKM2 expression may enhance the radiosensitivity of A549 cells and xenografts by regulation of autophagy, which holds promise for becoming an effective radiosensitizing target for non?small cell lung canc?er, but still needs to be confirmed by further studies.

Cisplatin-induced up-regulation and enrichment of BCRP and EHD2 on cell surface / 中国肿瘤临床

Objective:To establish the cisplatin-resistant human lung adenocarcinoma cell line A549/(DDP) cisplatin and to study the relationship between EHD2 and drug resistance. Methods:DDP-resistant human lung cancer cell line A549/DDP was established by gradual and stepwise dose enhancement. MTT was used to measure drug sensitivity. Western blot and immunofluorescence were used to evaluate expression and subcellular localization of EHD2 and breast cancer resistance protein (BCRP). Results:The DDP-resistant cell line A549/DDP was established, with a resistance index of 7.6. EHD2 and BCRP expressions both increased and were enriched on the cell surface membrane. Conclusion:Both EHD2 and BCRP expressions were enriched on the resistant cell surface membrane, suggesting that EHD2 endocytic protein stabilizes BCRP and is involved in drug resistance.

Expression of NTS in hepatocellular carcinoma(HCC)is associated with the formation of inflammatory microenvironment, more epithelial mesenchymal transition in cancer, and worse prognosis / 中国肿瘤临床

Objective:This work aims determine the expression of the neurotensin (NTS) gene in hepatocellular carcinoma (HCC) subgrouping using immunohistochemical staining (IHC) as well as to evaluate the correlation between the activation of NTS/IL-8 pathway in HCC and inflammatory response in microenvironment and epithelial mesenchymal transition (EMT) in cancer and in the prognosis of patients. Methods:Tumor tissues and corresponding adjacent normal tissue were collected from 64 cases of HCC patients. The expression levels of NTS protein and multiple inflammation and EMT-related proteins, including IL-8, VEGF, MMP9, CD68, E-Cadherin,β-Catenin, and Vimentin, were examined in 64 cases of paraffin-embedded HCC tissues using the immunohistochemistry (IHC) staining method. The clinical outcome and overall survival (OS) among 64 cases of HCC patients were compared. Results:We found that the frequency of NTS-expressing tissues among all HCC samples was 17.19%(11/64). Significantly increased IL-8 protein was confirmed in 90.91%of NTS+HCC samples and was positively correlated with the levels of NTS protein in cancer tissues (P=0.036), which implied the dysfunctional activation of NTS/IL-8 pathway in HCC. The levels of VEGF and MMP9 were significantly correlated with the co-expression of NTS and IL-8 in HCC. Evident features of EMT, including decreased membrane expression of E-Cadherin and increased accumulation of cytoplasmicβ-Catemin and Vimentin, were found in NTS+IL-8+samples. The co-expression of NTS and IL-8 in cancer was significantly correlated with the clinical outcomes of patients, as the mortality rate of NTS+IL-8+HCC patients is 2.5-fold higher than that of others after surgery (P=0.022).Accordingly, the OS of NTS+IL-8+HCC patients significantly decreased (24.65±4.45 m vs. 75.79±16.32 m, P=0.013), and these patients are at a higher risk of death at an expected hazard ratio (HR) of 3.457. Conclusion:The NTS/IL-8 pathway is dysfunctionally activated in a subgroup of HCC samples. Highly expressed NTS is associated with increased inflammatory response in microenvironment, enhanced EMT in cancer, and worse prognosis in HCC patients.