Overexpression of COX7A1 Promotes the Resistance of Gastric Cancer to Oxaliplatin and Weakens the Efficacy of Immunotherapy.

Gastric cancer (GC) is one of the most common clinical malignant tumors worldwide, with high morbidity and mortality. Presently, the overall response rate to immunotherapy is low, and current methods for predicting the prognosis of GC are not optimal. Therefore, novel biomarkers with accuracy, efficiency, stability, performance ratio, and wide clinical application are needed. Based on public data sets, the chemotherapy cohort and immunotherapy cohort from Sun Yat-sen University Cancer Center, a series of bioinformatics analyses, such as differential expression analysis, survival analysis, drug sensitivity prediction, enrichment analysis, tumor immune dysfunction and exclusion analysis, single-sample gene set enrichment analysis, stemness index calculation, and immune cell infiltration analysis, were performed for screening and preliminary exploration. Immunohistochemical staining and in vitro experiments were performed for further verification. Overexpression of COX7A1 promoted the resistance of GC cells to Oxaliplatin. COX7A1 may induce immune escape by regulating the number of fibroblasts and their cellular communication with immune cells. In summary, measuring the expression levels of COX7A1 in the clinic may be useful in predicting the prognosis of GC patients, the degree of chemotherapy resistance, and the efficacy of immunotherapy.

Construction of a gene model related to the prognosis of patients with gastric cancer receiving immunotherapy and exploration of COX7A1 gene function.

BACKGROUND: GC is a highly heterogeneous tumor with different responses to immunotherapy, and the positive response depends on the unique interaction between the tumor and the tumor microenvironment (TME). However, the currently available methods for prognostic prediction are not satisfactory. Therefore, this study aims to construct a novel model that integrates relevant gene sets to predict the clinical efficacy of immunotherapy and the prognosis of GC patients based on machine learning. METHODS: Seven GC datasets were collected from the Gene Expression Omnibus (GEO) database, The Cancer Genome Atlas (TCGA) database and literature sources. Based on the immunotherapy cohort, we first obtained a list of immunotherapy related genes through differential expression analysis. Then, Cox regression analysis was applied to divide these genes with prognostic significancy into protective and risky types. Then, the Single Sample Gene Set Enrichment Analysis (ssGSEA) algorithm was used to score the two categories of gene sets separately, and the scores differences between the two gene sets were used as the basis for constructing the prognostic model. Subsequently, Weighted Correlation Network Analysis (WGCNA) and Cytoscape were applied to further screen the gene sets of the constructed model, and finally COX7A1 was selected for the exploration and prediction of the relationship between the clinical efficacy of immunotherapy for GC. The correlation between COX7A1 and immune cell infiltration, drug sensitivity scoring, and immunohistochemical staining were performed to initially understand the potential role of COX7A1 in the development and progression of GC. Finally, the differential expression of COX7A1 was verified in those GC patients receiving immunotherapy. RESULTS: First, 47 protective genes and 408 risky genes were obtained, and the ssGSEA algorithm was applied for model construction, showing good prognostic discrimination ability. In addition, the patients with high model scores showed higher TMB and MSI levels, and lower tumor heterogeneity scores. Then, it is found that the COX7A1 expressions in GC tissues were significantly lower than those in their corresponding paracancerous tissues. Meanwhile, the patients with high COX7A1 expression showed higher probability of cancer invasion, worse clinical efficacy of immunotherapy, worse overall survival (OS) and worse disease-free survival (DFS). CONCLUSIONS: The ssGSEA score we constructed can serve as a biomarker for GC patients and provide important guidance for individualized treatment. In addition, the COX7A1 gene can accurately distinguish the prognosis of GC patients and predict the clinical efficacy of immunotherapy for GC patients.

MEX3C-Mediated Decay of SOCS3 mRNA Promotes JAK2/STAT3 Signaling to Facilitate Metastasis in Hepatocellular Carcinoma.

Tumor metastasis is one of the major causes of high mortality in patients with hepatocellular carcinoma (HCC). Sustained activation of STAT3 signaling plays a critical role in HCC metastasis. RNA binding protein (RBP)-mediated posttranscriptional regulation is involved in the precise control of signal transduction, including STAT3 signaling. In this study, we investigated whether RBPs are important regulators of HCC metastasis. The RBP MEX3C was found to be significantly upregulated in highly metastatic HCC and correlated with poor prognosis in HCC. Mechanistically, MEX3C increased JAK2/STAT3 pathway activity by downregulating SOCS3, a major negative regulator of JAK2/STAT3 signaling. MEX3C interacted with the 3'UTR of SOCS3 and recruited CNOT7 to ubiquitinate and accelerate decay of SOCS3 mRNA. Treatment with MEX3C-specific antisense oligonucleotide significantly inhibited JAK2/STAT3 pathway activation, suppressing HCC migration in vitro and metastasis in vivo. These findings highlight a novel mRNA decay-mediated mechanism for the disruption of SOCS3-driven negative regulation of JAK2/STAT3 signaling, suggesting MEX3C may be a potential prognostic biomarker and promising therapeutic target in HCC. SIGNIFICANCE: This study reveals that RNA-binding protein MEX3C induces SOCS3 mRNA decay to promote JAK2/STAT3 activation and tumor metastasis in hepatocellular carcinoma, identifying MEX3C targeting as a potential approach for treating metastatic disease.

Pan-Cancer Analyses Identify the CTC1-STN1-TEN1 Complex as a Protective Factor and Predictive Biomarker for Immune Checkpoint Blockade in Cancer.

The CTC1-STN1-TEN1 (CST) complex plays a crucial role in telomere replication and genome stability. However, the detailed mechanisms of CST regulation in cancer remain largely unknown. Here, we perform a comprehensive analysis of CST across 33 cancer types using multi-omic data from The Cancer Genome Atlas. In the genomic landscape, we identify CTC1/STN1 deletion and mutation and TEN1 amplification as the dominant alteration events. Expressions of CTC1 and STN1 are decreased in tumors compared to those in adjacent normal tissues. Clustering analysis based on CST expression reveals three cancer clusters displaying differences in survival, telomerase activity, cell proliferation, and genome stability. Interestingly, we find that CTC1 and STN1, but not TEN1, are co-expressed and associated with better survival. CTC1-STN1 is positively correlated with CD8 T cells and B cells and predicts a better response to immune checkpoint blockade in external datasets of cancer immunotherapy. Pathway analysis shows that MYC targets are negatively correlated with CTC1-STN1. We experimentally validated that knockout of CTC1 increased the mRNA level of c-MYC. Furthermore, CTC1 and STN1 are repressed by miRNAs and lncRNAs. Finally, by mining the connective map database, we discover a number of potential drugs that may target CST. In sum, this study illustrates CTC1-STN1 as a protective factor and provides broad molecular signatures for further functional and therapeutic studies of CST in cancer.

Intramedullary cervical spinal cord teratoma.

BACKGROUND: Intramedullary cervical spinal cord teratomas (ICTs) are extremely rare, and diagnosis and treatment are challenging. We conducted a systematic review of the literature on the diagnosis and treatment of ICT. METHOD: The presentation, imaging manifestations, diagnosis, management, surgery findings, prognosis and histology were reviewed following Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines. English-language studies and case reports published from inception to 2018 were retrieved. Data on presentation, imaging characteristics, diagnosis, management, surgery findings, outcomes, and histopathology were extracted. RESULTS: Ten articles involving 10 patients were selected. The lesions were located in the upper cervical vertebrae in 4 cases, whereas in the lower cervical vertebrae in the remaining 6 cases. In 5 cases, the lesions were located on the dorsal side of the spinal cord, and in the center of the spinal cord in the remaining 5 cases. Quadriparesis (60%), paraplegia (30%), monoplegia (10%), and neck pain (50%) were the main presentations. The lesion appeared as a intramedullary heterogeneous signal during an MRI scan, and the lesion signal would be partially enhanced after the contrast medium was applied. All patients underwent surgical intervention through a posterior approach. Neurological function improved postoperatively in all patients. Two patients with pathology confirmed to be immature teratomas experienced recurrence. CONCLUSION: ICTs are extremely rare entities that are mainly located in the center or dorsal part of the spinal cord which mainly manifest as quadriplegia and neck pain. MRI is a useful modality that provides diagnostic clues. Surgery from a posterior approach is the primary treatment, and the effect of adjuvant therapy remains uncertain. The prognosis is mainly related to the pathological nature of the tumor and not the method of resection.

Chemoradiotherapy in combination with radical surgery is associated with better outcome in cervical cancer patients.

OBJECTIVES: To retrospectively assess the influence of radical surgery following concurrent chemoradiotherapy (CCRT) on outcomes in cervical cancer (CC) patients. METHODS: Patients diagnosed with cervical squamous cell carcinoma or adenocarcinoma (FIGO stages IB2 to IIB) at the Yinbin Second People's Hospital between September 2008 and September 2013, were included in this study. Patients were classified into 2 groups based on the treatment received: surgery group (CCRT plus radical surgery) and non-surgery groups (CCRT only). In addition to clinical information, inter-group differences with respect to local control rate (LCR), local recurrence rate (LRR), metastasis rate, overall survival (OS), progress free survival(PFS) and complications were assessed. RESULTS: A total of 314 patients were included in the analysis. Parametrial invasion, pelvic lymph node metastasis, tumor diameter > 4 cm and presence of residual disease were risk factors for recurrence in the non-surgery group. In patients with risk factors, radical surgery significantly improved their clinical outcome. The 3-year/5-year LCR in the surgery and non-surgery groups was 88.3%/87.4% and 82.3%/77.5%, respectively (P = 0.04). The 3-year/5-year OS rate in the two groups was 87.1%/81.7% and 72.8%/67.3%, respectively (P = 0.001). The 3-year/5-year LRR in the two groups were 11.7%/12.6% and 17.7%/22.5%, respectively (P = 0.04). The metastasis rates in the two groups were 19.9% and 24.8%, respectively (P = 0.09). CONCLUSIONS: Surgery following CCRT could improve overall survival and progressfree survival. Radical surgery following CCRT appears to confer significant benefits including an increase in LCRs and decrease in LRR in CC patients with risk factors.

Nitidine chloride inhibited the expression of S phase kinase-associated protein 2 in ovarian cancer cells.

Nitidine chloride (NC) has been reported to exert its anti-tumor activity in various types of human cancers. However, the molecular mechanism of NC-mediated tumor suppressive function is largely unclear. In the current study, we used several approaches such as MTT, FACS, RT-PCR, Western blotting analysis, invasion assay, transfection, to explore the molecular basis of NC-triggered anti-cancer activity. We found that NC inhibited cell growth, induced cell apoptosis, caused cell cycle arrest in ovarian cancer cells. Emerging evidence has demonstrated that Skp2 plays an important oncogenic role in ovarian cancer. Therefore, we also explored whether NC exerts its biologic function via downregulation of Skp2 in ovarian cancer cells. We observed that NC significantly inhibited the expression of Skp2 in ovarian cancer cells. Notably, overexpression of Skp2 abrogated the anti-cancer activity induced by NC in ovarian cancer cells. Consistently, downregulation of Skp2 expression enhanced the sensitivity of ovarian cancer cells to NC treatment. Thus, inactivation of Skp2 by NC could be a novel strategy for the treatment of human ovarian cancer.

[The bio-effects of high single-dose radiation on xenografts of Lewis lung carcinoma].

OBJECTIVE: To investigate the bio-effects of high single-dose radiation on xenografts of Lewis lung carcinoma. METHODS: Female 8-week-old C57 mice bearing 4-6 mm diameter Lewis lung carcinoma tumors in the hind legs were divided into 3 groups, control group (0 Gy), high single-dose group (12 Gy/one fraction/day) and routine radiation group (22 Gy/11 fraction/15 d). The mean biological effective dose (BED) of both radiation groups was 26.4 Gy. Changes in hypoxia, DNA damage and cell cycle of the tumor cells at 1, 3, 8, 15 and 21 d after first irradiation was assessed by immunofluorescence and flow-cytometry and the tumor growth curve was also made. RESULTS: Compared to the fractionated treatment, the tumor growth was delayed after single dose irradiation. The percent of hypoxic cells after single dose radiation was lower than fractioned irradiation at 3, 8, 15 d after first radiation. The foci of gamma-H2AX showed that the single dose caused heavier DNA damages than fractioned irradiation at 1, 3 d after first radiation. The decline of G0/G1 percentage and increase of G2/M percentage of cells was found in both radiation schedules, but the G2/M percentage after single dose radiation was higher. CONCLUSION: In the C57 mice bearing Lewis lung carcinoma, the high single-dose regimen inhibits the tumor growth more than fractioned irradiation. We hypothesized that conversion of high single-dose to BED using the LQ formalism under estimated the in vivo effect of hypofractionated radiation.

Ablative hypofractionated radiotherapy normalizes tumor vasculature in lewis lung carcinoma mice model.

Ablative hypofractionated radiotherapy (HFRT) significantly improves the overall survival of inoperable non-small cell lung cancer (NSCLC) patients compared with conventional radiation therapy. However, the radiobiological mechanisms of ablative HFRT remain largely unknown. The purpose of this study was to investigate the dynamic changes of tumor vessels and perfusion during and after ablative hypofractionated radiotherapy. Lewis lung carcinoma-bearing mice were treated with sham (control) and ablative hypofractionated radiotherapy of 12 Gy in 1 fraction (12 Gy/1F) and 36 Gy in 3 fractions (36 Gy/3F). Tumor microvessel density (MVD), morphology and function were examined at different times after irradiation. The results showed that, compared to the controls the MVD and hypoxia in ablative HFRT groups decreased, which were accompanied by an increase in the number of pericytes and their coverage of vessels. Functional tests revealed that tumor hypoxia and perfusion were improved, especially in the 36 Gy/3F group. Our results revealed that ablative hypofractionated radiotherapy not only repressed MVD and hypoxia, but also increased the vascular perfusion and the number of pericyte-covered vessels, suggesting that ablative HFRT normalized the tumor vasculature.

[Detection of epidermal growth factor receptor gene mutation in non-small cell lung cancer by allele-specific oligonucleotide-PCR and bi-loop probe specific primer quantitative PCR].

OBJECTIVE: To compare the detection sensitivity of epidermal growth factor receptor (EGFR) mutations between allele specific oligonucleotide PCR (ASO-PCR) and bi-loop probe and specific primer quantitative PCR (BPSP-qPCR). METHODS: A total of 96 non-small cell lung cancer specimens were selected from West China Hospital from September 2009 to December 2010. ASO-PCR was developed to detect the presence of classical EGFR mutations. A total 39 available specimens were also tested by BPSP-qPCR. RESULTS: EGFR mutation detection rate was 30.2% (26/96) by ASO-PCR. The mutation rate was higher in female than in male patients [45.5% (20/44) vs. 17.3% (9/52), P = 0.003], non-smokers than smokers [44.1% (26/59) vs. 8.1% (3/37), P < 0.001] and adenocarcinomas than other subtypes of lung cancer [37.0% (27/73) vs. 8.7% (2/23), P = 0.01]. Among mutation negative cases by ASO-PCR, BPSP-qPCR increased the rate of detection of 19-del and L858R mutation by 10.3% (4/39) in adenocarcinomas and non-smoking subset. Overall, the mutation detection rate of BPSP-qPCR was higher than that of ASO-PCR [66.7% (26/39) vs. 41.0% (16/39), P = 0.02]. CONCLUSION: BPSP-qPCR has a better detection sensitivity than that of ASO-PCR.

[Detection of epidermal growth factor receptor gene mutations in non-small cell lung cancer using bi-loop probe specific primer quantitative PCR].

OBJECTIVE: To investigate the sensitivity of bi-loop probe and specific primer quantitative PCR (BPSP-qPCR) in the detection of epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer (NSCLC). METHODS: BPSP-qPCR was employed to examine the presence of mutations of EFGR exon 19 through 21. Correlation of the mutations with clinicopathological characteristics and types of tumor samples were performed. RESULTS: In the cohort of 265 specimens, 30.2% (80/265) mutations were found to be 19-del and/or L858R. Females (39.7%, 31/78), non-smokers (41.0%, 43/105) and adenocarcinoma patients (37.8%, 51/135) had a higher mutation rate (P<0.05) among 184 patients whose profiles were available. T790M combined with 19-del and/or L858R accounted for 3.3% (6/184) of the mutations. Male metastatic tumors (29.6%, 8/27), pleural fluids of females (42.9%, 9/21) and non-smokers (40.7%, 11/27) were found to have higher percentage of 19-del and/or L858R mutations, in contrast, no mutations were found in the metastatic lesions of non-adenocarcinoma patients (P>0.05). CONCLUSIONS: BPSP-qPCR is a robust method in detection of EGFR mutations with high consistency and sensitivity. The difference of EGFR mutations in primary tumors, metastatic lesions and pleural fluids suggests that EGFR tyrosine kinase inhibitors (EGFR-TKI) treatment may have variable treatment effects depending on the tumor sites.