SNHG4-mediated PTEN destabilization confers oxaliplatin resistance in colorectal cancer cells by inhibiting ferroptosis.

Oxaliplatin resistance poses a significant challenge in colorectal cancer (CRC) therapy, necessitating further investigation into the underlying molecular mechanisms. This study aimed to elucidate the regulatory role of SNHG4 in oxaliplatin resistance and ferroptosis in CRC. Our findings revealed that treatment with oxaliplatin led to downregulation of SNHG4 expression in CRC cells, while resistant CRC cells exhibited higher levels of SNHG4 compared to parental cells. Silencing SNHG4 attenuated oxaliplatin resistance and reduced the expression of resistance-related proteins MRD1 and MPR1. Furthermore, induction of ferroptosis effectively diminished oxaliplatin resistance in both parental and resistant CRC cells. Notably, ferroptosis induction resulted in decreased SNHG4 expression, whereas SNHG4 overexpression suppressed ferroptosis. Through FISH, RIP, and RNA pull-down assays, we identified the cytoplasmic localization of both SNHG4 and PTEN, establishing that SNHG4 directly targets PTEN, thereby reducing mRNA stability in CRC cells. Silencing PTEN abrogated the impact of SNHG4 on oxaliplatin resistance and ferroptosis in CRC cells. In vivo experiments further validated the influence of SNHG4 on oxaliplatin resistance and ferroptosis in CRC cells through PTEN regulation. In conclusion, SNHG4 promotes resistance to oxaliplatin in CRC cells by suppressing ferroptosis through instability of PTEN, thus serves as a target for patients with oxaliplatin-base chemoresistance.

Identification and diagnostic potential of hsa_circ_101303 in colorectal cancer: unraveling a regulatory network.

BACKGROUND: The role of novel circular RNAs (circRNAs) in colorectal cancer (CRC) remains to be determined. This study aimed to identify a novel circRNA involved in CRC pathogenesis, assess its diagnostic value, and construct a regulatory network. METHODS: Differential expression analysis was conducted using circRNA datasets to screen for differentially expressed circRNAs. The expression of selected circRNAs was validated in external datasets and clinical samples. Diagnostic value of plasma circRNA levels in CRC was assessed. A competing endogenous RNA (ceRNA) network was constructed for the circRNA using TCGA dataset. RESULTS: Analysis of datasets revealed that hsa_circ_101303 was significantly overexpressed in CRC tissues compared to normal tissues. The upregulation of hsa_circ_101303 in CRC tissues was further confirmed through the GSE138589 dataset and clinical samples. High expression of hsa_circ_101303 was associated with advanced N stage, M stage, and tumor stage in CRC. Plasma levels of hsa_circ_101303 were markedly elevated in CRC patients and exhibited moderate diagnostic ability for CRC (AUC = 0.738). The host gene of hsa_circ_101303 was also found to be related to the TNM stage of CRC. Nine miRNAs were identified as target miRNAs for hsa_circ_101303, and 27 genes were identified as targets of these miRNAs. Subsequently, a ceRNA network for hsa_circ_101303 was constructed to illustrate the interactions between the nine miRNAs and 27 genes. CONCLUSIONS: The study identifies hsa_circ_101303 as a highly expressed circRNA in CRC, which is associated with the progression of the disease. Plasma levels of hsa_circ_101303 show promising diagnostic potential for CRC. The ceRNA network for hsa_circ_101303 provides valuable insights into the regulatory mechanisms underlying CRC.

Systematic analyzing a five- miRNA panel and its diagnostic value of plasma expression in colorectal cancer.

BACKGROUND: Aberrant expression of miRNAs have been implicated in cancers, but the role of miRNAs in colorectal cancer (CRC) remains need to be elucidated. This study aimed to identify miRNAs that related to colorectal cancer (CRC) pathogenesis and determine the diagnostic value. METHODS: Three GEO datasets (GSE128449, GSE35602 and GSE49246) with 131 samples were used to screen miRNAs that differential expression between tumor and control tissues. The expression of the identified miRNAs was validated in 50 clinical tissue samples and the GSE35834 dataset. The clinical significance of these miRNAs was analyzed in the TCGA dataset and clinical tissue samples. The expression of miRNAs in tissues and plasma samples were tested by RT-PCR assay in clinical samples, and their diagnostic value was determined. RESULTS: The analysis of three GEO datasets revealed that miR-595 and miR-1237 were upregulated, while miR-126, miR-139, and miR-143 were downregulated in CRC tissues compared to control tissues. The differential expression of the five miRNAs in CRC tissues was confirmed using clinical tissue samples and GEO databases. There was no significant correlation between the TNM stage and tumor stage of CRC and any of the five miRNAs. Plasma expression of the miRNAs differed significantly between CRC and non-cancer patients, and each miRNA had moderate diagnostic value for CRC. Combining the five miRNAs provided better diagnostic potential for CRC than a single miRNA. CONCLUSIONS: This study demonstrated that five miRNAs were related to the pathogenesis of CRC, but independent of the stage of CRC; Plasma expression of these miRNAs have moderate diagnostic value, and combination of these miRNAs showed better diagnostic ability in CRC.

The feasibility of laparoscopic TSME preserving the left colic artery and superior rectal artery for upper rectal cancer.

BACKGROUND: Laparoscopic tumor-specific mesorectal excision (TSME) preserving the left colic artery and superior rectal artery is still a technically challenging procedure. We conducted this study to demonstrate the feasibility of this procedure for upper rectal cancer. METHODS: A total of 184 patients with upper rectal cancer were retrospectively analyzed in our cancer center between April 2010 and April 2017. These patients were treated with either laparoscopic TSME (n = 46) or laparoscopic total mesorectal excision (TME) (n = 138). In the TSME group, the left colonic artery and superior rectal artery were preserved while they were not in the TME group. RESULTS: The operation time in the TSME group was longer than that in the TME group (218.56 ± 35.85 min vs. 201.13 ± 42.65 min, P = 0.004). Furthermore, the number of resected lymph nodes in the TSME group was greater than that in the TME group (19.43 ± 9.46 vs. 18.03 ± 7.43, P = 0.024). The blood loss between the TSME and TME groups was not significant. No mortality occurred in either the TSME or TME groups. One patient in the TME group underwent conversion to laparotomy. The total postoperative complication rates in the TSME and TME groups were 8.7% and 17.4%, respectively. There was no difference in severe complications between the two groups (anastomotic leakage and stenosis). CONCLUSIONS: Laparoscopic TSME preserving the left colic artery and superior rectal artery can be safely conducted for upper rectal cancer.

Prognostic and clinical significance of syndecan-1 in colorectal cancer: a meta-analysis.

BACKGROUND: Syndecan-1 plays a vital role in the suppression, transformation, and migration of several cancer types, including colorectal cancer (CRC). However, the prognostic and clinical significance of syndecan-1 in CRC remains conflicting. Therefore, we performed a meta-analysis to clarify this relationship. METHODS: A comprehensive literature search for relevant studies published up to December 2014 was performed using PubMed, EMBASE, and Ovid library database. The odds ratio (OR) and pooled hazard ratio (HR) with their 95 % confidence intervals (CI) were used to estimate the effects. RESULTS: Ten studies with 888 CRC patients were selected for evaluation. The results showed that syndecan-1 expression was lower in CRC tissue than in normal colorectal tissue (OR = 0.02, 95 % CI = 0.00-0.09), and lower in the advanced stage than in the early stage (OR = 2.24, 95 % CI = 1.14 - 4.42). Additionally, syndecan-1 expression was higher in well and moderately differentiated CRC than in poorly differentiated CRC (OR = 2.91, 95 % CI = 1.21-6.98); no significant difference was found in patients with or without lymph node metastasis (OR = 0.91, 95 % CI = 0.34-2.43) and distant metastasis (OR = 0.89, 95 % CI = 0.19-4.21). The pooled results showed that syndecan-1 expression was not associated with survival in CRC patients (HR = 0.93, 95 % CI = 0.86-1.01). CONCLUSION: This meta-analysis indicated that loss of syndecan-1 expression is associated with CRC development, histological differentiation, and clinical stage, but not with lymph node metastasis and distant metastasis. In addition, these findings fail to support the prognostic significance of syndecan-1 in CRC.

Elucidating the role of angiogenesis-related genes in colorectal cancer: a multi-omics analysis.

Background: Angiogenesis plays a pivotal role in colorectal cancer (CRC), yet its underlying mechanisms demand further exploration. This study aimed to elucidate the significance of angiogenesis-related genes (ARGs) in CRC through comprehensive multi-omics analysis. Methods: CRC patients were categorized according to ARGs expression to form angiogenesis-related clusters (ARCs). We investigated the correlation between ARCs and patient survival, clinical features, consensus molecular subtypes (CMS), cancer stem cell (CSC) index, tumor microenvironment (TME), gene mutations, and response to immunotherapy. Utilizing three machine learning algorithms (LASSO, Xgboost, and Decision Tree), we screen key ARGs associated with ARCs, further validated in independent cohorts. A prognostic signature based on key ARGs was developed and analyzed at the scRNA-seq level. Validation of gene expression in external cohorts, clinical tissues, and blood samples was conducted via RT-PCR assay. Results: Two distinct ARC subtypes were identified and were significantly associated with patient survival, clinical features, CMS, CSC index, and TME, but not with gene mutations. Four genes (S100A4, COL3A1, TIMP1, and APP) were identified as key ARCs, capable of distinguishing ARC subtypes. The prognostic signature based on these genes effectively stratified patients into high- or low-risk categories. scRNA-seq analysis showed that these genes were predominantly expressed in immune cells rather than in cancer cells. Validation in two external cohorts and through clinical samples confirmed significant expression differences between CRC and controls. Conclusion: This study identified two ARG subtypes in CRC and highlighted four key genes associated with these subtypes, offering new insights into personalized CRC treatment strategies.

lncRNA SNHG4 inhibits ferroptosis by orchestrating miR-150-5p/c-Myb axis in colorectal cancer.

LncRNAs have shown to regulate ferroptosis in colorectal cancer (CRC), but the mechanism remains largely unknown. This study unveiled the mechanism of SNHG4 underlying ferroptosis in CRC. RNA-seq and RT-PCR assay confirmed SNHG4 was decreased after Erastin treatment in CRC cells. Overexpression of SNHG4 inhibited and silence promoted CRC cells ferroptosis. SNHG4 was positively correlated to c-Myb in CRC tissues and both located in cytoplasm of CRC cells. RIP and RNA pull-down assays verified the interaction between SNHG4 and c-Myb. Silence of c-Myb alleviated the suppressing effect on ferroptosis by SNHG4 in CRC cells. Dual-luciferase reporter assay revealed that SNHG4 sponging miR-150-5p in CRC cells. Overexpression of SNHG4 decreased the miR-150-5p and increased c-Myb expression. c-Myb was a direct target gene of miR-150-5p in CRC cells. Moreover, effect of CDO1 on ferroptosis was regulated transcriptionally by c-Myb, overexpression of c-Myb reduce CDO1 expression and enhance the GPX4 levels. The animal models confirmed that regulatory effect of SNHG4 on miR-150-5p and c-Myb after inducing ferroptosis. We concluded that SNHG4 inhibited Erastin-induce ferroptosis in CRC, this effect is via sponging miR-150-5p to regulate c-Myb expression, and activated CDO1/GPX4 axis. These findings provide insights into the regulatory mechanism of SNHG4 on ferroptosis.

Efficacy evaluation of nilotinib treatment in different genomic subtypes of gastrointestinal stromal tumors: A meta-analysis and systematic review.

Nilotinib has been used as a third-line drug for gastrointestinal stromal tumors (GISTs) after a failure of sunitinib. In this study, we aimed to evaluate the efficacy of nilotinib in different genomic subtypes of GISTs. We searched the English articles through EMBASE, Cochrane Library and PubMed Database regarding to the use of nilotinib on GISTs, which published up to February 15, 2019. Inclusion criteria were: GISTs patients received nilotinib in a clinical trial and had detailed genetic subtype records (such as KIT exon 9, KIT exon 11, or PDGFRA mutations, or wild-type). The clinical benefit rate was used to assess the efficacy of nilotinib. A total of 3 studies involving 218 GISTs were included in this meta-analysis. The overall OR (KIT group vs WT group) was 3.26 (95% CI: 1.14-9.28; P = 0.027, Pheterogeneity = 0.613). The overall OR in KIT exon 11 group vs WT group was 5.30 (95% CI: 1.79-15.68; P = 0.003, Pheterogeneity = 0.409). The overall OR in KIT exon 9 group vs WT group was 0.13 (95% CI: 0.02-0.86; P = 0.035, Pheterogeneity = 0.229). The overall OR in KIT exon 11 group vs exon 9 group was 9.96 (95% CI: 0.39-254.66; P < 0.0001, Pheterogeneity = 0.024). Different genotypes of GISTs showed different responses to nilotinib, and KIT exon 11-mutant GISTs mostly benefited from nilotinib, followed by KIT exon 9-mutant or WT one.

Genome­scale analysis to identify potential prognostic microRNA biomarkers for predicting overall survival in patients with colon adenocarcinoma.

The aim of the present study was to identify potential prognostic microRNA (miRNA) biomarkers for colon adenocarcinoma (COAD) prognostic prediction using the dataset of The Cancer Genome Atlas (TCGA). The genome­wide miRNA sequencing dataset and corresponding COAD clinical information were downloaded from TCGA. Prognosis­related miRNA screening was performed by genome­wide multivariable Cox regression analysis and used for prognostic signature construction. Ten miRNAs (hsa­mir­891a, hsa­mir­6854, hsa­mir­216a, hsa­mir­378d­1, hsa­mir­92a­1, hsa­mir­4709, hsa­mir­92a­2, hsa­mir­210, hsa­mir­940 and hsa­mir­887) were identified as prognostic miRNAs and used for further prognostic signature construction. The 10­miRNA prognostic signature showed good performance in prognosis prediction (adjusted P<0.0001; adjusted hazard ratio, 4.580; 95% confidence interval, 2.783­7.538). In the time­dependent receiver operating characteristic analysis, the area under the curve was 0.735, 0.788, 0.806, 0.806, 0.775 and 0.900 for 1­, 2­, 3­, 4­, 5­ and 10­year COAD overall survival prediction, respectively. Comprehensive survival analysis suggested that the 10­miRNA prognostic signature is an independent prognostic factor in COAD, with a better performance in COAD overall survival prediction than other traditional clinical parameters. Functional enrichment indicated that the corresponding target genes were significantly enriched in multiple biological processes and pathways, including regulation of cell proliferation, cell cycle, cell growth, and Wnt and transforming growth factor­ß signaling pathways. In conclusion, our present study identified a 10­miRNA expression signature that may serve as a potential prognostic biomarker in COAD patients.