LAMP2A regulates cisplatin resistance in colorectal cancer through mediating autophagy.

BACKGROUND: Drug resistance is an important constraint on clinical outcomes in advanced cancers. LAMP2A is a limiting protein in molecular chaperone-mediated autophagy. This study was aimed to explore LAMP2A function in cisplatin (cis-diamminedichloroplatinum, DDP) resistance colorectal cancer (CRC) to seek new ideas for CRC clinical treatment. METHODS: In this study, LAMP2A expression was analyzed by molecular experimental techniques,such as qRT-PCR and western blot. Then, LAMP2A in cells was interfered by cell transfection experiments. Subsequently, the function of LAMP2A on proliferation, migration, invasion, DDP sensitivity, and autophagy of CRC/DDP cells were further investigated by a series of experiments, such as CCK-8, transwell, and western blot. RESULTS: We revealed that LAMP2A was clearly augmented in DDP-resistant CRC and was related to poor patient prognosis. Functionally, LAMP2A insertion remarkably CRC/DDP proliferation, migration, invasion ability and DDP resistance by strengthen autophagy. In contrast, LAMP2A knockdown limited the proliferation, migration, and invasion while heightened cellular sensitivity to DDP by restraining autophagy in CRC/DDP cells. Furthermore, LAMP2A silencing was able to curb tumor formation and enhance sensitivity to DDP in vivo. CONCLUSION: In summary, LAMP2A boosted malignant progression and DDP resistance in CRC/DDP cells through mediating autophagy. Clarifying LAMP2A function in DDP resistance is promising to seek cancer therapies biomarkers targeting LAMP2A activity.

TREM1 facilitates the development of gastric cancer through regulating neutrophil extracellular traps-mediated macrophage polarization.

Triggering receptor expressed on myeloid cell 1 (TREM1) elevation is associated with the unfavorable prognosis of gastric cancer (GC) patients. This work uncovered the effects and mechanism of TREM1 in GC. IHC staining examined TREM1 expression in GC tissues. TREM1-knockout and TREM1 knock-in mice were generated prior to the construction of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced GC mice model. H&E staining detected the pathological alternations of gastric tissues. IHC staining tested Ki67 expression. Wright-Giemsa staining performed neutrophil counting and flow cytometry analysis measured neutrophil infiltration. ELISA analyzed serum and tissue myeloperoxidase (MPO) levels and serum MPO-DNA levels. Immunofluorescence, Western blotting and related kits detected NETs formation. Immunofluorescence and IHC staining evaluated macrophage polarization. In MNNG-treated GES-1 cells and phorbal myristate acetate (PMA)-treated neutrophils, TREM1 expression was also examined. CCK-8 method and Western blotting assayed cell proliferation. Western blotting and immunofluorescence detected NETs formation. Flow cytometry analysis detected the changes of macrophage typing. TREM1 was overexpressed in tumor tissues, MNNG-treated GES-1 cells and PMA-treated neutrophils. TREM1 deficiency hindered tumor growth, reduced neutrophil infiltration, NETs formation and stimulated M1 macrophage polarization in MNNG-induced GC models. Neutrophil extracellular traps (NETs) degrader DNase-1 countervailed the impacts of TREM1 on MNNG-induced GC models in vivo. Collectively, TREM1 knockdown obstructed NETs-mediated M2 macrophage polarization to hamper GC progression.

Identification of an m6A-related lncRNA prognostic signature in colorectal cancer.

Data sets of colorectal cancer (CRC) were obtained from The Cancer Genome Atlas (TCGA), three N6-methyladenosine (m6A) subtypes were identified using 21 m6A-related long noncoding RNAs (lncRNAs) and differential m6A subtypes of different CRC tumors were determined in this study to evaluate the m6A expression and the prognosis of patients with CRC. Subsequently, eight key lncRNAs were identified based on co-expression with 21 m6A-related genes in CRC tumors using the single-factor Cox and least absolute shrinkage and selection operator. Finally, an m6A-related lncRNA risk score model of CRC tumor was established using multifactor Cox regression based on the eight important lncRNAs and found to have a better performance in evaluating the prognosis of patients in the TCGA-CRC data set. TCGA-CRC tumor samples were divided based on the risk scores: high and low. Then, the clinical characteristics, tumor mutation load, and tumor immune cell infiltration difference between the high- and low-risk-score groups were explored, and the predictive ability of the risk score was assessed for immunotherapeutic benefits. We found that the risk score model can determine the overall survival, be a relatively independent prognostic indicator, and better evaluate the immunotherapeutic benefits for patients with CRC. This study provides data support for accurate immunotherapy in CRC.

Interleukin-8 Regulates the Autophagy and Apoptosis in Gastric Cancer Cells via Regulating PI3K/Akt Signaling Pathway.

Objective: To explore the role and mechanism of interleukin-8-mediated autophagy regulation of gastric cancer (GC) cells in GC. Methods: After cell culture, the SGC7901 cell line was separated into the control group and IL-8 (20 ng/mL) group, IL-8 (40 ng/mL) group, and IL-8 (60 ng/mL) group, to verify the effects of the PI3K/Akt signal path on the modulation of autophagy in GC cells. Western blot detected autophagy markers, ATG12-ATG5 complexes, autophagy-associated pathways, and apoptosis-associated factors in GC cells. Transwell was utilized to identify invasion capability. Results: Compared with the control group, the expression of LC3II, Atg5, ATG7, Beclin1, Bax, C-cas3, C-cas9, P-PI3K, P-Akt, and ATG12-ATG5 was remarkably elevated in the IL-8 (60 ng/mL) group, IL-8 (20 ng/mL) group, and the IL-8 (40 ng/mL) group. The expression of P62 and Bcl-2 in the IL-8 (60 ng/mL) group was also lower than that of the IL-8 (20 ng/mL) group and IL-8 (40 ng/mL) group, in contrast to the controls. The invasive quantity of GC SGC7901 cells in the IL-8 (60 ng/mL) group was also remarkably higher in contrast to the IL-8 (20 ng/mL) and IL-8 (40 ng/mL) groups. The relative expressions of LC3II, Atg5, ATG7, Beclin1, Bax, C-cas3, C-cas9, P-PI3K, P-Akt, and ATG12-ATG5 complex proteins in LY294002 group were considerably elevated. LC3II, Atg5, ATG7, Beclin1, Bax, C-cas3, C-cas9, P-PI3K, P-Akt, and ATG12-ATG5 were decreased in the IL-8 + LY294002 group. The relative expressions of P62 and Bcl-2 proteins in the IL-8 + LY294002 group were remarkably elevated, and the invasion of SGC7901 cells in the IL-8 group was elevated. In contrast to the IL-8 group, the invasion quantity of gastric cancer SGC7901 cells in the IL-8 + LY294002 group was considerably decreased. Conclusion: IL-8 promotes autophagy and aggression and suppresses apoptosis of GC SGC7901 cells by regulating PI3K/AKT pathway phosphorylation.

Identification of a Prognostic Colorectal Cancer Model Including LncRNA FOXP4-AS1 and LncRNA BBOX1-AS1 Based on Bioinformatics Analysis.

Background: Knowledge about the prognostic role of long noncoding RNA (lncRNA) in colorectal cancer (CRC) is limited. Therefore, we constructed a lncRNA-related prognostic model based on data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). Materials and Methods: CRC transcriptome and clinical data were downloaded from the GSE20916 dataset and the TCGA database, respectively. R software was used for data processing and analysis. The differential lncRNA expression within the two datasets was first screened, and then intersections were measured. Cox regression and the Kaplan-Meier method were used to evaluate the effects of various factors on prognosis. The area under the curve (AUC) of the receiver operating characteristic curve and a nomogram based on multivariate Cox analysis were used to estimate the prognostic value of the lncRNA-related model. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were applied to elucidate the significantly involved biological functions and pathways. Results: A total of 11 lncRNAs were crossed. The univariate Cox analysis screened out two lncRNAs, which were analyzed in the multivariate Cox analysis. A nomogram based on the two lncRNAs and other clinicopathological risk factors was constructed. The AUC of the nomogram was 0.56 at 3 years and 0.71 at 5 years. The 3-year nomogram model was compared with the ideal model, which showed that some indices of the 3-year model were consistent with the ideal model, suggesting that our model was highly accurate. The GO and KEGG enrichment analyses showed that positive regulation of secretion by cells, positive regulation of secretion, positive regulation of exocytosis, endocytosis, and the calcium signaling pathway were differentially enriched in the two-lncRNA-associated phenotype. Conclusions: A two-lncRNA prognostic model of CRC was constructed by bioinformatics analysis. The model had moderate prediction accuracy. LncRNA BBOX1-AS1 and lncRNA FOXP4-AS1 were identified as prognostic biomarkers.

TYMSOS drives the proliferation, migration, and invasion of gastric cancer cells by regulating ZNF703 via sponging miR-4739.

Gastric cancer (GC) is a kind of malignancy originating from the epithelium of gastric mucosa. Long noncoding RNAs (lncRNAs) are tightly related to the GC progression. Herein, our research was meant to investigate a novel lncRNA thymidylate synthetase opposite strand (TYMSOS) in GC. Quantitative real-time polymerase chain reaction was used to analyze TYMSOS expression in GC cells. 5-Ethynyl-2'-deoxyuridine, flow cytometry analysis, and transwell assay detected the influence of TYMSOS on GC cell proliferation, apoptosis, migration, and invasion. Subcellular fractionation and fluorescent in situ hybridization assays determined the cellular localization of TYMSOS in GC cells. Bioinformatics programs, RNA-binding protein immunoprecipitation, RNA pull-down, and luciferase reporter assays measured the molecular interplays of TYMSOS in GC cells. In brief, TYMSOS was highly expressed in GC cells, and TYMSOS silence inhibited GC cell proliferation, migration, and invasion while elevating cell apoptosis. Functionally, TYMSOS functioned as a competing endogenous RNA to posttranscriptionally modulate GC progression. TYMSOS interacted with miR-4739 to regulate its target gene zinc finger protein 703. Collectively, our study proved the tumor-promoting role of TYMSOS in GC cells, which might offer the utility value for GC treatment.

Long non-coding RNA LINC00997 silencing inhibits the progression and metastasis of colorectal cancer by sponging miR-512-3p.

We aimed to study the role of LINC00997 in the metastasis of colorectal cancer (CRC). LINC00997 and miR-512-3p expression in the primary colorectal cancer (NCRC) tissues and metastatic colorectal cancer (MCRC) tissues were detected using RT-qPCR. The Cancer Genome Atlas database was used to evaluate LINC00997 levels in the NCRC and MCRC tissues, and the correlations of LINC00997 expression with distant metastasis (M), regional lymph node metastasis (N), age and tumor stage were analyzed. Subsequently, RT-qPCR was performed to determine the expression of metastasis-related genes in MCRC tissues and analyze the correlation of LINC00997 or miR-512-3p level with the protein expression of metastasis-related genes. In vitro, LINC00997 expression in several CRC cell lines was examined. After LINC00997 silencing, cell invasion and migration were evaluated with Transwell and wound healing assays, respectively. The expression of metastasis- and EMT-related proteins was measured. Additionally, the potential interaction between LINC00997 and miR-512-3p was verified using a luciferase reporter assay. Rescue assays were conducted to clarify the regulatory effects of LINC00997 and miR-512-3p on CRC development. Results revealed that LINC00997 was frequently overexpressed in MCRC tissues, which was positively related to the tumor metastasis and stage. Additionally, LINC00997 was significantly elevated in CRC cells and LINC00997 silencing inhibited the invasion, migration and EMT of CRC cells, which was restored by miR-512-3p inhibitor. Luciferase reporter assay confirmed that LINC00997 could target miR-512-3p. In conclusion, LINC00997 regulated the metastasis of CRC by targeting miR-512-3p, providing some insights into the regulatory mechanism of CRC.

miR-133a-3p Targets SUMO-Specific Protease 1 to Inhibit Cell Proliferation and Cell Cycle Progress in Colorectal Cancer.

Dysregulation of SUMO-specific protease 1 (SENP1) expression has been reported in several kinds of cancer, including human colorectal and prostate cancers, proposing SENP1 as an oncogene with a critical role in cancer progression. miR-133a-3p has been reported as a tumor suppressor in several malignant neoplasias. However, the precise molecular mechanisms underlying its role in colorectal cancer remain largely unknown. The aim of this work was to investigate the relationship between miR-133a-3p and SENP1 in colorectal cancer cells. We found that miR-133a-3p expression was downregulated in colorectal cancer tissues. In silico analyses indicated that SENP1 is one of the target genes of miR-133a-3p. Overexpression of miR-133a-3p mimics was able to inhibit cell growth with G1 arrest of colorectal cancer cells. Overexpression of miR-133a-3p antisense promoted cell growth of colorectal cancer cells. The luciferase reporter experiments showed that miR-133a-3p regulated the expression of SENP1 by combining with its 3'-UTR and resulted in downregulation of SENP1 and upregulation of CDK inhibitors such as p16, p19, p21, and p27. These results suggest that the miR-133a-3p-SENP1 axis might play a role in cell proliferation and cell cycle regulation of colorectal cancer cells.