A pan-cancer analysis of SLC1A5 in human cancers.

Background: The alanine-serine-cysteine transporter 2, ASCT2 (solute carrier family 1 member 5, SLC1A5), is a major transporter of the amino acid, glutamine. Although SLC1A5 has been reported to be associated with some types of cancer, less pan-cancer analysis, which would give a comprehensive understanding of SLC1A5 across human cancers, has been carried out. Methods: We used the TCGA and GEO databases to investigate the oncogenic role of SLC1A5. We examined gene and protein expression, survival, genetic mutations, protein phosphorylation, immunocyte infiltration and the related genes correlated pathways. In HCT116 cells, SLC1A5 was silenced by siRNAs and the mRNA and protein was checked by Q-PCR and WB, respectively and the cellular function was assessed by CCK8, cell cycle and apoptosis. Results: We found that SLC1A5 was over-expressed in multiple types of cancer and that elevated expression of SLC1A5 was associated with poor survival in many cancers. The missense mutation of R330 H/C was associated with poor survival, especially in uterine carcinosarcoma. Furthermore, we found enhanced phosphorylation of S503 in uterine corpus endometrial carcinoma and lung adenocarcinoma. In addition, elevated SLC1A5 expression was associated with immune cell infiltration in many cancers. KEGG and GO analysis showed that SLC1A5 and its related genes were involved in central carbon metabolism in cancer, due to their amino acid transport activity. The cellular function indicated that SLC1A5 may influence the cell proliferation by affecting DNA synthesis. Conclusions: Our findings highlighted the important role of SLC1A5 in tumorigenesis and provided insights into potential cancer treatment strategies.

Proteomic analysis reveals CAAP1 negatively correlates with platinum resistance in ovarian cancer.

The present study sought to investigate the correlation between CAAP1 and platinum resistance in ovarian cancer and to preliminarily explore the potential biological function of CAAP1. Proteomic analysis was used to analyze differentially expressed proteins in platinum-sensitive and -resistant tissue samples of ovarian cancer. The Kaplan-Meier plotter was used for prognostic analysis. Immunohistochemistry assay and chi-square test were employed to explore the relationship between CAAP1 and platinum resistance in tissue samples. Lentivirus transfection, immunoprecipitation-mass spectrometry, and bioinformatics analysis were used to determine the potential biological function of CAAP1. Based on results, the expression level of CAAP1 was significantly higher in platinum-sensitive tissues compared to that in resistant tissues. Chi-square test demonstrated that there is a negative correlation between high expression of CAAP1 and platinum resistance. Overexpression of CAAP1 increased cis­platinum sensitivity of the A2780/DDP cell line likely via the mRNA splicing pathway by interacting with the splicing factor AKAP17A. In summary, there is a negative correlation between high expression of CAAP1 and platinum resistance. CAAP1 might be a potential biomarker for platinum resistance in ovarian cancer. SIGNIFICANCE: Platinum resistance is a key factor affecting the survival of ovarian cancer patients. Understanding the mechanisms of platinum resistance is highly important for ovarian cancer management. Here, we performed the DIA- and DDA-based proteomics to analyze differentially expressed proteins in tissue and cell samples of ovarian cancer. We found that the protein identified as CAAP1, which was first reported to be involved in the regulation of apoptosis, may be negatively correlates with platinum resistance in ovarian cancer. In addition, we also found that CAAP1 enhanced the sensitivity of platinum-resistant cells to cis­platinum via the mRNA splicing pathway by interacting with the splicing factor AKAP17A. Our data would be useful to reveal novel molecular mechanisms of platinum resistance in ovarian cancer.

Thiol oxidative stress-dependent degradation of transglutaminase2 via protein S-glutathionylation sensitizes 5-fluorouracil therapy in 5-fluorouracil-resistant colorectal cancer cells.

5-Fluorouracil (5-Fu) is a first-line drug for colorectal cancer (CRC) therapy. However, the development of 5-Fu resistance limits its chemotherapeutic effectiveness and often leads to poor prognoses of CRC. Transglutaminase 2 (TGM2), a member of the transglutaminase family, is considered to be associated with chemoresistance through apoptotic prevention in various cancers including CRC. TGM2 was found to be overexpressed in two 5-Fu-resistant CRC cell lines and down-regulated by increased thiol oxidative stress induced by inhibition of glutathione reductase (GR). The present study aimed to explore the role of TGM2 in 5-Fu-resistant CRC and the mechanism of action by which the elevated thiol oxidative stress down-regulates TGM2 protein level. The results revealed that 5-Fu-resistance induced by overexpression of TGM2 in CRC cells was reversed through up-regulation of thiol oxidative stress. Knockdown of TGM2 increased the chemosensitivity of CRC cells to 5-Fu. Thiol oxidative stress potentially enhanced the therapeutic effect of 5-Fu in the resistant CRC cells by promotion of 5-Fu-induced apoptosis through down-regulation of TGM2. The elevated thiol oxidative stress increased the S-glutathionylation of TGM2 and led to proteasomal degradation of TGM2. Furthermore, Cys193 was identified as the S-glutathionylation site in TGM2, and its mutation resulted in thiol oxidative stress-mediated CRC cell apoptotic resistance. TGM2-induced EMT was also suppressed by the elevated thiol oxidative stress. A xenograft tumor model confirmed the effect of thiol oxidative stress in the reversal of 5-Fu resistance in CRC cells in vivo. TGM2 protein expression level was found to be significantly higher in human CRC specimens than in non-cancerous colorectal tissues. Taken together, the present data suggest an important role of TGM2 in 5-Fu resistance in CRC cells. Up-regulation of thiol oxidative stress could be a potential therapeutic approach for treating 5-Fu-resistant CRC and TGM2 may serve as a potential therapeutic target of thiol oxidative stress.

Targeting lactate dehydrogenase a improves radiotherapy efficacy in non-small cell lung cancer: from bedside to bench.

BACKGROUND: Lactate dehydrogenase A (LDHA) is overexpressed and associated with poor prognosis in many kinds of cancer. In the current study, we evaluated the prognostic value of LDHA expression in non-small cell lung cancer (NSCLC), and tested whether LDHA inhibition might improve radiotherapy efficacy in NSCLC. METHODS: LDHA expression was investigated in NSCLC patients, using online database and further verified by immunohistochemistry. The prognostic value of LDHA was evaluated using Kaplan-Meier plotter database. In vitro, two NSCLC cell lines were pretreated with oxamate, an inhibitor of LDHA, and colony formation method was performed to determine cellular radiosensitivity. Comet assay was used to detect DNA damage after irradiation. Flow cytometry was applied to test cell cycle progression and apoptosis, and monodansylcadaverine (MDC) staining was used to examine cell autophagy. RESULTS: Both mRNA and protein levels of LDHA expression were up-regulated in NSCLC tissues. High LDHA expression was a poor prognostic factor and associated with radioresistance in NSCLC patients. LDHA inhibition by oxamate remarkably increased radiosensitivity in both A549 and H1975 cancer cells, and enhanced ionizing radiation (IR)-induced apoptosis and autophagy, accompanied by cell cycle distribution alternations. Furthermore, LDHA inhibition induced reactive oxygen species (ROS) accumulation and cellular ATP depletion, which might increase DNA injury and hinder DNA repair activity. CONCLUSIONS: Our study suggests that inhibition of LDHA may be a potential strategy to improve radiotherapy efficacy in NSCLC patients, which needs to be further tested by clinical trials.

SLC7A7 is a prognostic biomarker correlated with immune infiltrates in non-small cell lung cancer.

BACKGROUND: SLC7A7 (solute carrier family 7, amino acid transporter light chain, y + L system, member 7) is a critical gene in the regulation of cationic amino acid transport. However, the relationships between SLC7A7 and prognosis and tumor-infiltrating lymphocytes in different cancers remain unclear. METHODS: SLC7A7 expression was analyzed using the Oncomine database and Tumor Immune Estimation Resource (TIMER) site. The enrichment of the GO (Gene Oncology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways was conducted by DAVID. We evaluated the influence of SLC7A7 on clinical prognosis using the PrognoScan database. The functional state of SLC7A7 in various types of cancers was analyzed by CancerSEA. The relationships between SLC7A7 and cancer immune infiltrates was investigated by TIMER. Furthermore, correlations between SLC7A7 expression and gene marker sets of immune infiltrates were analyzed by TIMER and Gene Expression Profiling Interactive Analysis (GEPIA). The expression of SLC7A7 was verified by GEO database and immunohistochemistry. RESULTS: A lung cancer cohort study (GSE31210) showed that high SLC7A7 expression was associated with poor overall survival (OS) and relapse-free survival (RFS). In addition, SLC7A7 had a significant impact on the prognosis of diverse cancers. SLC7A7 expression was positively correlated with infiltrating levels of CD4 + and CD8 + T cells, macrophages, neutrophils and dendritic cells (DCs) in non-small cell lung cancer (NSCLC). SLC7A7 expression was also strongly correlated with various immune marker sets in NSCLC. CONCLUSIONS: These results indicated a role for SLC7A7 in infiltration of CD8 + T cells, CD4 + T cells, tumor-associated macrophages (TAMs), neutrophils and DCs in multiple cancers, and regulation of T cell exhaustion and Tregs in NSCLC. These findings suggest that SLC7A7 could be served as a biomarker for prognosis and immune infiltration in NSCLC.

E2F1/2/4 mRNA is associated with immune infiltration and are potential biomarkers for the prognosis of human gastric carcinoma.

BACKGROUND: E2Fs are genes that regulate DNA synthesis and the cell cycle by encoding a family of transcription factors. Increasing experimental evidence has revealed that E2Fs play key roles in tumor progression in various types of cancer. METHODS: We investigated the survival, expression and transcriptional data of E2F1/2/4 in gastric cancer (GC) patients using the immunohistochemistry assay, Kaplan-Meier Plotter, cBioPortal, String, and GEPIA databases. The plasma of GC patients was analyzed using the real-time reverse transcription polymerase chain reaction (RT-PCR) assay. The correlation between E2F1/2/4 expression and clinical features was analyzed using the quartile method. As well, the correlation between E2F1/2/4 and GC immune infiltration was also investigated using the TIMER database. Database of Immune Cell Expression (DICE) was also used to analyze correlations between SOX4 and immune responses. RESULTS: RT-PCR and tissue immunohistochemistry confirmed that E2F1/2/4 was highly expressed in serum and GC tissue samples of GC patients, the expression of which was not affected by patient age and gender. Also, the survival analysis revealed that low levels of E2F1/2/4 expression were significantly associated with a longer overall survival (OS) in GC patients. E2F1/2/4 was correlated with patient prognosis and immune cell infiltration, including B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and DCs in GC. Our findings indicated that E2F1/2/4 could be used as a prognostic biomarker and indicator of immune infiltration in GC. CONCLUSIONS: This study revealed that E2F1/2/4 could be a promising indicator for tumor-associated immune infiltration and prognosis in GC patients.

miR-588 is a prognostic marker in gastric cancer.

In an effort to identify a novel microRNA (miRNA) as a gastric cancer (GC) treatment target and prognostic biomarker, we surveyed The Cancer Genome Atlas database and found that miR-588 expression is low in GC tissues. This was confirmed by real-time reverse transcription polymerase chain reaction assays of GC patient plasma samples and SGC7901 and MNK28 cells. A constructed miRNA-mRNA network showed that CXCL5, CXCL9, and CXCL10 are target genes of miR-588. Analysis of the miRWalk database revealed that miR-588 directly binds to CXCL5 and CXCL9. Overexpression of miR-588 reduced GC cell proliferation in vitro and in vivo. High expression of miR-588 inhibited Ki-67 expression in vivo. The FunRich database also showed that CXCL5, CXCL9, and CXCL10 are involved in immune responses, while the Database of Immune Cell Expression showed they are differentially expressed in CD8+ T cells. High expression of CXCL9 and CXCL10 correlated positively with infiltrating levels of CD4+ T and CD8+ T cells in stomach adenocarcinoma. High expression of miR-588, CXCL5, CXCL9, and CXCL10 was associated with prolonged survival of GC patients. These findings indicate that miR-588 is a biomarker for tumor-associated immune infiltration and a prognostic marker in GC patients.

2019-nCoV may create complications in colon cancer patients with ACE2 expression.

Since December 2019, a novel coronavirus (2019-nCoV) has emerged from Wuhan, China, causing symptoms in humans. Much remains unknown about 2019-nCoV, especially the additional risks that 2019-nCoV infection may pose for colon cancer patients. Many reports show that angiotensin converting enzyme II (ACE2) is the cell receptor through which 2019-nCoV enters host cells, and this is similar to the cell entry mechanism of SARS coronavirus. Previous studies show that ACE2 is highly expressed in the gastrointestinal tract, especially in the colon. In patients with colon cancer, ACE2 expression is significantly increased in tumor tissues compared to tissues from patients with other types of cancer. One of the known regulators of endocytosis is the serine protease (TMPRSS2) and AP2-associated protein kinase 1 (AAK1), which also facilitates the passage of viruses into cells. Furthermore, the Database of Gene expression profiling interactive analysis suggests that expression levels for ACE2, TMPRSS2, and AAK1 are positively correlated in colon cells. Therefore, our findings predict that 2019-nCoV will create increased complications for patients with colon cancer.

ZC3H12D is a prognostic biomarker associated with immune cell infiltration in lung adenocarcinoma.

BACKGROUND: ZC3H12 family members have an important role in tumorigenesis and development. However, the relationship between ZC3H12 family members and the prognosis of lung adenocarcinoma (LUAD) and tumor infiltrating lymphocytes is not clear. METHODS: The expression of ZC3H12 family members in LUAD was analyzed by UALCAN. UALCAN, Kaplan-Meier Plotter, and GEPIA were used to evaluate the effect of ZC3H12 family members on the prognosis of LUAD. The relationship between prognostic ZC3H12 family members and 14 functional states of LUAD was studied by CancerSEA. The correlation between ZC3H12 and immune cell infiltration was studied by TIMMER. In addition, the correlation between ZC3H12D expression and an immune infiltration gene marker set was analyzed by TISIDB and GEPIA. Finally, the expression of ZC3H12D in LUAD was further verified by the GEO database and immunohistochemical staining. RESULTS: The combined prognostic analysis of UALCAN, Kaplan-Meier Plotter, and GEPIA showed that the up-regulated expression of ZC3H12D mRNA was closely related to an improvement in overall survival rate (OS) in patients with LUAD. There was no significant correlation between ZC3H12D and 14 functional states of LUAD. Further analysis showed that the expression of ZC3H12D was positively correlated with the infiltration of B cells and CD4+T cells in LUAD. The expression of ZC3H12D was also positively correlated with immune markers in LUAD, including B cell-derived TNF and LTA cytokines, CXCL13, and its receptor CXCR5. Immunohistochemical staining showed that the expression of ZC3H12D in LUAD tissue samples was higher than normal lung tissues. CONCLUSIONS: These findings suggest that multiple ZC3H12 family members are associated with the prognosis of patients with LUAD tumors. The increased expression of ZC3H12D was correlated with improved prognosis. ZC3H12D was shown to be associated with the level of immune cell infiltration, including B cells and CD4+T cells. Thus, ZC3H12D can be used as a biomarker to judge the prognosis and immune infiltration of LUAD.

MiR-596 down regulates SOX4 expression and is a potential novel biomarker for gastric cancer.

BACKGROUND: Gastric cancer (GC) is one of the most commonly diagnosed malignancies of the human digestive tract, and currently there is a dearth of effective biomarkers for this disease. METHODS: MiR-598 expression levels were analyzed by the cancer genome atlas (TCGA database) mining and verified in GC patient plasma using real-time reverse transcription polymerase chain reaction (RT-PCR) assay. We used the GEPIA and UALCAN databases and immunohistochemistry (IHC) to analyze SOX4 expression. The MTT assay assessed MNK28 and SGC7901 cell proliferation after transfection with miR-596 plasmids. The analytical tools, Functional Enrichment Analysis Tool (FunRich), Database of Immune Cell Expression (DICE) and Tumor IMmune Estimation Resource (TIMER) were used to analyze correlations between SOX4 and immune responses. Furthermore, a Kaplan Meier plotter database explored correlations between miR-596, SOX4 and overall patient survival. RESULTS: Data from TCGA and RT-PCR indicated that miR-598 was lowly expressed in GC patients. The miRWalk database showed that SOX4 was the target genes of miR-596 and also revealed that miR-596 bound directly to SOX4. MiR-596 over-expression further depressed GC cell proliferation. In addition, the FunRich database showed that SOX4 was involved in immune responses, and was further shown to be differentially expressed in CD4+ T cells by DICE. Specifically, TIMER indicated that high expression of SOX4 was negatively correlated with infiltrating CD4+ T cells in stomach adenocarcinoma (STAD). Moreover, high expression of miR-596 and low expression of SOX4 prolonged the overall survival (OS) of GC patients. CONCLUSIONS: Our study reveals a crucial role for miR-596 in tumor-associated immune infiltration and predicting prognoses in GC patients.

Bioinformatics study on cisplatin resistance related genes in non-small cell lung cancer / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：通过分析非小细胞肺癌顺铂敏感株及耐药株的基因芯片表达数据，筛选差异基因及关键通路，构建蛋白相互作用网络，探讨关键集群功能。方法:从GEO数据库获得基因芯片表达数据，利用GEO2R工具筛选差异基因，通过STRING数据库和Cytoscape软件构建蛋白相互作用网络，经DAVID富集得到相关特征基因与信号通路信息。结果：通过芯片分析共获得481个差异表达基因，相比于敏感细胞株，顺铂获得性耐药细胞株中有418个上调基因和63个下调基因。差异基因功能主要富集在piRNA代谢、DNA甲基化修饰、细胞有丝分裂及细胞周期进程等信号通路。蛋白复合物预测得到主要功能集群6个，分别与细胞趋化性、细胞角化性、piRNA代谢过程、细胞因子受体相互作用、细胞因子分泌调节及染色质沉默相关生物进程相关。结论:本研究利用生物信息学方法，发现顺铂耐药细胞株特征基因及信号通路，其中SAA1、KRT5、TDRD9、BCL2A1、CSF1R和HIST1H1A等显著上调基因及其功能集团可能是非小细胞肺癌顺铂耐药的潜在分子机制，为临床精准治疗提供新的理论依据。

Comprehensive Profiling of Gene Copy Number Alterations Predicts Patient Prognosis in Resected Stages I-III Lung Adenocarcinoma.

Background: Lung adenocarcinoma (LUAD) possesses a poor prognosis with a low 5-year survival rate even for stages I-III resected patients, it is thus critical to understand the determinants that affect the survival and discover new potentially prognostic biomarkers. Somatic copy number alterations (CNAs) are major source of genomic variations driving tumor evolution, CNAs screening may identify prognostic biomarkers. Methods: Oncoscan MIP array was used to analyze the patterns of CNAs on formalin fixed paraffin embedded(FFPE) tumor specimens from 163 consecutive stage I-III resected LUAD patients, 145 out of which received platinum-based adjuvant chemotherapy. Results: Of the 163 patients, 91(55.8%) were recurred within 3 years after surgery. The most common aberrations in our cohort were 1q, 5p, 5q, 7p, 8q, 14p, 16p, 17q, 20q for copy number gains and 8p, 9p, 13p, 16q, 18q for losses. The GISTIC2 analysis produced 45 amplification peaks and 40 deletion peaks, involving some reported genes TERT, EGFR, MYC, CCND1, CDK4, MDM2, ERBB2, NKX2-1, CCNE1, and CDKN2A, most of which were consistent with TCGA database. The amplifications of 12p12.1 (CMAS, GOLT1B, YS2, LDHB, RECQL, ETNK1, IAPP, PYROXD1, KRAS) and KDM5A were correlated with worse prognosis in our cohort, this result was further validated in 506 LUAD patients from TCGA. In addition, 163 patients could be well-classified into five groups, and the clinical outcomes were significantly different based on threshold copy number at reoccurring alteration peaks. Among the 145 patients who received adjuvant chemotherapy, focal amplification of ERBB2 and deletion of 4q34.3 were found to be specific in relapsed patients, this result was validated in an independent group of Imielinski et al., demonstrating these two CNAs may contribute to resected LUAD recurrence after adjuvant chemotherapy. Conclusion: This study suggests that CNAs profiling may be a potential prognostic classifier in resected LAUD patients. Amplifications of 12p12.1 and KDM5A might be prognostic biomarkers for LUAD, and amplification of ERBB2 and deletion of 4q34.3 predicted early relapse after adjuvant chemotherapy. These novel findings may provide implication for better implementation of precision therapy for lung cancer patients.

Development of new prognostic model based on pretreatment ßLRI and LLRI for stage IE/IIE upper aerodigestive tract ENKTL, nasal type.

To identify simple non-invasive prognostic factors for extranodal natural killer/T cell lymphoma (ENKTL), we have investigated the prognostic value of pretreatment ß2-microglobin to lymphocytes ratio index (ßLRI) or lactate dehydrogenase to lymphocytes ratio index (LLRI), by analyzing the retrospective data from 211 ENKTL patients. Receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off value of pretreatment ßLRI and LLRI. The univariate analysis indicated that Ann Arbor Stage (p = 0.008), Eastern Cooperative Oncology Group score (ECOG) (p = 0.009), International Prognostic Index (IPI) (p = 0.023), ßLRI (p = 0.003), LLRI (p = 0.04), neutrophil-lymphocyte ratio index (p = 0.025) and monocyte/granulocyte to lymphocyte ratio (p = 0.030) were significantly associated with overall survival (OS) in ENKTL patients. However, multivariate analysis demonstrated that only Ann Arbor Stage (p = 0.028), ßLRI (p < 0.001) and LLRI (p = 0.006) were only correlated independently with OS. Furthermore, ßLRI and LLRI based new prognostic model showed improved discrimination for stage IE/IIE upper aerodigestive tract in ENKTL patients than IPI and Korean Prognostic Index. Overall, our study concluded that new ßLRI-based prognosis model is useful to stratify ENKTL patients and higher ßLRI and LLRI can act as independent prognostic predictor candidates in early stage ENKTL.

Brain microvascular endothelium induced-annexin A1 secretion contributes to small cell lung cancer brain metastasis.

Small cell lung cancer is the most aggressive histologic subtype of lung cancer, with a strong predilection for metastasizing to brain early. However, the cellular and molecular basis is poorly known. Here, we provided evidence to reveal the role of annexin A1 in small cell lung cancer metastasis to brain. Firstly, the elevated annexin A1 serum levels in small cell lung cancer patients were associated with brain metastasis. The levels of annexin A1 were also upregulated in NCI-H446 cells, a small cell lung cancer cell line, upon migration into the mice brain. More interestingly, annexin A1 was secreted by NCI-H446 cells in a time-dependent manner when co-culturing with human brain microvascular endothelial cells, which was identified with the detections of annexin A1 in the co-cultured cellular supernatants by ELISA and western blot. Further results showed that blockage of annexin A1 in the co-cultured cellular supernatants using a neutralized antibody significantly inhibited NCI-H446 cells adhesion to brain endothelium and its transendothelial migration. Conversely, the addition of Ac2-26, an annexin A1 mimic peptide, enhanced these effects. Furthermore, knockdown of annexin A1 in NCI-H446 cells prevented its transendothelial migration in vitro and metastasis to mice brain in vivo. Our data showed that small cell lung cancer cell in brain microvasculature microenvironment could express much more annexin A1 and release it outside, which facilitated small cell lung cancer cell to gain malignant properties of entry into brain. These findings provided a potential target for the management of SCLC brain metastasis.