A new prognostic model based on gamma-delta T cells for predicting the risk and aiding in the treatment of clear cell renal cell carcinoma.

BACKGROUND: ccRCC is the prevailing form of RCC, accounting for the majority of cases. The formation of cancer and the body's ability to fight against tumors are strongly connected to Gamma delta (γδ) T cells. METHODS: We examined and analyzed the gene expression patterns of 535 individuals diagnosed with ccRCC and 72 individuals serving as controls, all sourced from the TCGA-KIRC dataset, which were subsequently validated through molecular biology experiments. RESULTS: In ccRCC, we discovered 304 module genes (DEGRGs) that were ex-pressed differentially and linked to γδ T cells. A risk model for ccRCC was constructed using 13 differentially DEGRGs identified through univariate Cox and LASSO regression analyses, which were found to be associated with prognosis. The risk model exhibited outstanding performance in both the training and validation datasets. The comparison of immune checkpoint inhibitors and the tumor immune microenvironment between the high- and low-risk groups indicates that immunotherapy could lead to positive results for low-risk patients. Moreover, the inhibition of ccRCC cell proliferation, migration, and invasion was observed in cell culture upon knocking down TMSB10, a gene associated with different types of cancers. CONCLUSIONS: In summary, we have created a precise predictive biomarker using a risk model centered on γδ T cells, which can anticipate clinical results and provide direction for the advancement of innovative targeted therapies.

Intracellular Protein Adsorption Behavior and Biological Effects of Polystyrene Nanoplastics in THP-1 Cells.

Micro(nano)plastics (MNPs) are emerging pollutants that can adsorb pollutants in the environment and biological molecules and ultimately affect human health. However, the aspects of adsorption of intracellular proteins onto MNPs and its biological effects in cells have not been investigated to date. The present study revealed that 100 nm polystyrene nanoplastics (NPs) could be internalized by THP-1 cells and specifically adsorbed intracellular proteins. In total, 773 proteins adsorbed onto NPs with high reliability were identified using the proteomics approach and analyzed via bioinformatics to predict the route and distribution of NPs following cellular internalization. The representative proteins identified via the Kyoto Encyclopedia of Genes and Genomes pathway analysis were further investigated to characterize protein adsorption onto NPs and its biological effects. The analysis revealed that NPs affect glycolysis through pyruvate kinase M (PKM) adsorption, trigger the unfolded protein response through the adsorption of ribophorin 1 (RPN1) and heat shock 70 protein 8 (HSPA8), and are chiefly internalized into cells through clathrin-mediated endocytosis with concomitant clathrin heavy chain (CLTC) adsorption. Therefore, this work provides new insights and research strategies for the study of the biological effects caused by NPs.

Transcriptomic Analysis of THP-1 Cells Exposed by Monosodium Urate Reveals Key Genes Involved in Gout.

BACKGROUND: Gout is a common inflammatory arthritis, which is mainly caused by the deposition of monosodium urate (MSU) in tissues. Transcriptomics was used to explore the pathogenesis and treatment of gout in our work. OBJECTIVE: The objective of the study was to analyze and validate potential therapeutic targets and biomarkers in THP-1 cells that were exposed to MSU. METHODS: THP-1 cells were exposed to MSU. The inflammatory effect was characterized, and RNA-Seq analysis was then carried out. The differential genes obtained by RNA-Seq were analyzed with gene expression omnibus (GEO) series 160170 (GSE160170) gout-related clinical samples in the GEO database and gout-related genes in the GeneCards database. From the three analysis approaches, the genes with significant differences were verified by the differential genes' transcription levels. The interaction relationship of long non-coding RNA (lncRNA) was proposed by ceRNA network analysis. RESULTS: MSU significantly promoted the release of IL-1ß and IL-18 in THP-1 cells, which aggravated their inflammatory effect. Through RNA-Seq, 698 differential genes were obtained, including 606 differential mRNA and 92 differential `LncRNA. Cross-analysis of the RNA-Seq differential genes, the GSE160170 differential genes, and the gout-related genes in GeneCards revealed a total of 17 genes coexisting in the tripartite data. Furthermore, seven differential genes-C-X-C motif chemokine ligand 8 (CXCL8), C-X-C motif chemokine ligand 2 (CXCL2), tumor necrosis factor (TNF), C-C motif chemokine ligand 3 (CCL3), suppressor of cytokine signaling 3 (SOCS3), oncostatin M (OSM), and MIR22 host gene (MIR22HG)-were verified as key genes that analyzed the weight of genes in pathways, the enrichment of inflammationrelated pathways, and protein-protein interaction (PPI)nodes combined with the expression of genes in RNA-Seq and GSE160170. It is suggested that MIR22HG may regulate OSM and SOCS3 through microRNA 4271 (miR-4271), OSM, and SOCS3m; CCL3 through microRNA 149-3p (miR-149-3p); and CXCL2 through microRNA 4652-3p (miR-4652-3p). CONCLUSION: The potential of CXCL8, CXCL2, TNF, CCL3, SOCS3, and OSM as gout biomarkers and MIR22HG as a therapeutic target for gout are proposed, which provide new insights into the mechanisms of gout biomarkers and therapeutic methods.

HPV18 E6 inhibits α-ketoglutarate-induced pyroptosis of esophageal squamous cell carcinoma cells via the P53/MDH1/ROS/GSDMC pathway.

Oncogene E6 plays a critical role in the development and progression of esophageal cancer caused by human papillomavirus (HPV) infection. Alpha-ketoglutarate (AKG) is a key metabolite in the tricarboxylic acid cycle and has been widely used as a dietary and anti-ageing supplement. In this study, we found that treating esophageal squamous carcinoma cells with a high dose of AKG can induce cell pyroptosis. Furthermore, our research confirms that HPV18 E6 inhibits AKG-induced pyroptosis of esophageal squamous carcinoma cells by lowering P53 expression. P53 downregulates malate dehydrogenase 1 (MDH1) expression; however, MDH1 downregulates L-2-hydroxyglutarate (L-2HG) expression, which inhibits a rise in reactive oxygen species (ROS) levels-as L-2HG is responsible for excessive ROS. This study reveals the actuating mechanism behind cell pyroptosis of esophageal squamous carcinoma cells induced by high concentrations of AKG, and we posit the molecular pathway via which the HPV E6 oncoprotein inhibits cell pyroptosis.

Bioinformatics Analysis and Verification of Metabolic Abnormalities in Esophageal Squamous Carcinoma.

BACKGROUND: Although esophageal carcinoma (EC) is one of the most common cancers in the world, details of its pathogenesis remain unclear. Metabolic reprogramming is a main feature of EC. Mitochondrial dysfunction, especially the decrease in mitochondrial complex I (MTCI), plays an important role in the occurrence and development of EC. OBJECTIVE: The objective of the study was to analyze and validate the metabolic abnormalities and the role of MTCI in esophageal squamous cell carcinoma. METHODS: In this work, we collected transcriptomic data from 160 esophageal squamous carcinoma samples and 11 normal tissue samples from The Cancer Genome Atlas (TCGA). The OmicsBean and GEPIA2 were used to conduct an analysis of differential gene expression and survival in clinical samples. Rotenone was used to inhibit the MTCI activity. Subsequently, we detected lactate production, glucose uptake, and ATP production. RESULTS: A total of 1710 genes were identified as being significantly differentially expressed. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analysis suggested that these differentially expressed genes (DEGs) were significantly enriched in various pathways related to carcinoma tumorigenesis and progression. Moreover, we further identified abnormalities in metabolic pathways, in particular, the significantly low expression of multiple subunits of MTCI genes (ND1, ND2, ND3, ND4, ND4L, ND5, and ND6). Rotenone was used to inhibit the MTCI activity of EC109 cells, and it was found that the decrease in MTCI activity promoted HIF1A expression, glucose consumption, lactate production, ATP production, and cell migration. CONCLUSION: Our results indicated the occurrence of abnormal metabolism involving decreased mitochondrial complex I activity and increased glycolysis in esophageal squamous cell carcinoma (ESCC), which might be related to its development and degree of malignancy.

Transcriptomic analysis of the effects of the HPV18 E6E7 gene on the cell death mode in esophageal squamous cell carcinoma.

Human papillomavirus (HPV) infection is one of the main causes of esophageal carcinoma (ESCA), and its carcinogenic mechanisms in ESCA require further investigation. E6 and E7 are HPV oncogenes, and their genomic integration is a crucial reason for the transformation of host cells into cancer cells. In order to reveal the role of oncogenes E6 and E7 in ESCA cells, the RNA-Seq raw data for HPV18-positive and -negative esophageal squamous cell carcinoma (ESCC) samples derived from the NCBI BioProject database were analyzed, and the differentially expressed genes were identified. Moreover, differentially expressed genes were enriched significantly in multiple cell death pathways, including apoptosis (cyclin-dependent kinase inhibitor 2A, plakophilin 1 and desmoglein 3), pyroptosis (gasdermin A, gasdermin C, NLR family pyrin domain containing 3, absent in melanoma 2, NLR family pyrin domain containing 1 and Toll like receptor 1) and autophagy (Unc-51 like autophagy activating kinase 1, adrenoceptor beta 2). Consequently, the effects of cisplatin-induced apoptosis and Hank's balanced salt solution-induced autophagy, and α-ketoglutarate-induced pyroptosis in the ESCC-expressing E6 and E7 cells were verified. Therefore, the expression of E6E7 may culminate in the inhibition of multiple cell death modes, which may also be one of the mechanisms of oncogene-induced carcinogenesis.

Dual signal magnification for ultrasensitive biosensing based on well-regulated SERS of AuNTs@AuHg and DSN-assisted amplification.

AuNTs@AuHg alloy with well-regulated SERS properties was proposed, which displayed wonderful SERS intensity and effective salt resistance. Using miRNA-21 as a model analyte and combining with DSN-assisted amplification, a dual signal amplification strategy for ultrasensitive miRNA biosensing with a low detection limit (0.53 fM) and satisfactory selectivity was designed.

Targeting HIC1/TGF-ß axis-shaped prostate cancer microenvironment restrains its progression.

Prostate cancer (PCa) is a malignant tumor that seriously threatens men's health worldwide. Recently, stromal cells in the tumor microenvironment (TME) have been reported to contribute to the progression of PCa. However, the role and mechanism of how PCa cells interact with stromal cells to reshape the TME remain largely unknown. Here, using a spontaneous prostate adenocarcinoma (PRAD) model driven by the loss of Pten and Hic1, we found that M2 macrophages markedly infiltrated the stroma of Pten and Hic1 double conditional knockout (dCKO) mice compared with those in control (Ctrl) mice due to higher TGF-ß levels secreted by HIC1-deleted PCa cells. Mechanistically, TGF-ß in TME promoted the polarization of macrophages into "M2" status by activating the STAT3 pathway and modulating c-Myc to upregulate CXCR4 expression. Meanwhile, TGF-ß activated the fibroblasts to form cancer-associated fibroblasts (CAFs) that secrete higher CXCL12 levels, which bound to its cognate receptor CXCR4 on M2 macrophages. Upon interaction with CAFs, M2 macrophages secreted more CXCL5, which promoted the epithelial-mesenchymal transition (EMT) of PCa via CXCR2. Moreover, using the TGF-ß receptor I antagonist, galunisertib, significantly inhibited the tumor growth and progression of the TRAMP-C1 cell line-derived subcutaneous tumor model. Finally, we confirmed that the stromal microenvironment was shaped by TGF-ß in HIC1-deficient PCa and was associated with the progression of PCa.

Inhibition of N-Acetyltransferase 10 Suppresses the Progression of Prostate Cancer through Regulation of DNA Replication.

Cancer suppression through the inhibition of N-acetyltransferase 10 (NAT10) by its specific inhibitor Remodelin has been demonstrated in a variety of human cancers. Here, we report the inhibitory effects of Remodelin on prostate cancer (PCa) cells and the possible associated mechanisms. The prostate cancer cell lines VCaP, LNCaP, PC3, and DU145 were used. The in vitro proliferation, migration, and invasion of cells were measured by a cell proliferation assay, colony formation, wound healing, and Transwell assays, respectively. In vivo tumor growth was analyzed by transplantation into nude mice. The inhibition of NAT10 by Remodelin not only suppressed growth, migration, and invasion in vitro, but also the in vivo cancer growth of prostate cancer cells. The involvement of NAT10 in DNA replication was assessed by EdU labeling, DNA spreading, iPOND, and ChIP-PCR assays. The inhibition of NAT10 by Remodelin slowed DNA replication. NAT10 was detected in the prereplication complex, and it could also bind to DNA replication origins. Furthermore, the interaction between NAT10 and CDC6 was analyzed by Co-IP. The altered expression of NAT10 was measured by immunofluorescence staining and Western blotting. Remodelin markedly reduced the levels of CDC6 and AR. The expression of NAT10 could be altered under either castration or noncastration conditions, and Remodelin still suppressed the growth of in vitro-induced castration-resistant prostate cancers. The analysis of a TCGA database revealed that the overexpression of NAT10, CDC6, and MCM7 in prostate cancers were correlated with the Gleason score and node metastasis. Our data demonstrated that Remodelin, an inhibitor of NAT10, effectively inhibits the growth of prostate cancer cells under either no castration or castration conditions, likely by impairing DNA replication.

LncRNA RP11-89 facilitates tumorigenesis and ferroptosis resistance through PROM2-activated iron export by sponging miR-129-5p in bladder cancer.

Long non-coding RNAs (lncRNAs) act as important regulators of tumorigenesis and development in bladder cancer. However, the underlying molecular mechanisms remain elusive. We previously identified a novel lncRNA signature related to immunity and progression in bladder cancer. Here we further explored the function of RP11-89, a lncRNA discovered in the previous signature. Loss- and gain-of function experiments were performed using CCK-8 assay, flow cytometry, Transwell assays, scratch tests and subcutaneous nude mouse models. High-throughput RNA sequencing was conducted to identify dysregulated genes in bladder cancer cells with RP11-89 knockdown or overexpression. Regulation of RP11-89 on miR-129-5p and PROM2 was explored through luciferase reporter assay, RIP assay and RNA pull-down assay. RP11-89 promoted cell proliferation, migration and tumorigenesis and inhibited cell cycle arrest via the miR-129-5p/PROM2 axis. We found that RP11-89 "sponges" miR-129-5p and upregulates PROM2. Elevated PROM2 in cells was associated with attenuated ferroptosis through iron export, formation of multivesicular bodies and less mitochondrial abnormalities. We demonstrated that RP11-89 is a novel tumorigenic regulator that inhibits ferroptosis via PROM2-activated iron export. RP11-89 may serve as a potential biomarker for targeted therapy in bladder cancer.

Comprehensive analysis of alternative splicing profiling reveals novel events associated with prognosis and the infiltration of immune cells in prostate cancer.

BACKGROUND: Alternative splicing (AS) is believed to play a vital role in tumor development. Therefore, comprehensive investigation of AS and its biological function in prostate cancer (PCa) is crucial. METHODS: The AS profiling of 489 patients with PCa was obtained from The Cancer Genome Atlas (TCGA) SpliceSeq database. Bioinformatics tools were used to describe splicing associations and build prognostic models. Unsupervised clustering of the determined prognostic AS events and the relationship with immune characteristics were also explored. RESULTS: In total, 20,723 AS events were detected and 2,805 were identified in PCa. In the regulatory networks, the data suggested a significant correlation between splicing factor (SF) expression and AS events. To stratify the progression risk of PCa patients, prognostic models were constructed using splicing patterns. Six AS events were screened out as independent prognostic factors for progression-free survival. Based on the gene features, we constructed the combined prognostic predictors model, and the receiver operating characteristic (ROC) curve for this model reached a high area under the ROC curve (AUC) of 0.729793, indicating a favorable ability to predict patient outcomes. Through unsupervised clustering analysis, the correlations between AS-based clusters and prognosis as well as immune characteristics were revealed. The correlation analysis on TIMER revealed the relationship between gene expression and immune cell infiltration. CONCLUSIONS: This in-depth genome-wide analysis of the AS profiling in PCa revealed unique AS events associated with cancer progression and the infiltration of immune cells, with potential for predicting outcomes and therapeutic responses.

Autophagy-Mediated Clearance of Free Genomic DNA in the Cytoplasm Protects the Growth and Survival of Cancer Cells.

The cGAS (GMP-AMP synthase)-mediated senescence-associated secretory phenotype (SASP) and DNA-induced autophagy (DNA autophagy) have been extensively investigated in recent years. However, cGAS-mediated autophagy has not been elucidated in cancer cells. The described investigation revealed that active DNA autophagy but not SASP activity could be detected in the BT-549 breast cancer cell line with high micronucleus (MN) formation. DNA autophagy was identified as selective autophagy of free genomic DNA in the cytoplasm but not nucleophagy. The process of DNA autophagy in the cytosol could be initiate by cGAS and usually cooperates with SQSTM1-mediated autophagy of ubiquitinated histones. Cytoplasmic DNA, together with nuclear proteins such as histones, could be derived from DNA replication-induced nuclear damage and MN collapse. The inhibition of autophagy through chemical inhibitors as well as the genomic silencing of cGAS or SQSTM1 could suppress the growth and survival of cancer cells, and induced DNA damage could increase the sensitivity to these inhibitors. Furthermore, expanded observations of several other kinds of human cancer cells indicated that high relative DNA autophagy or enhancement of DNA damage could also increase or sensitize these cells to inhibition of DNA autophagy.

Diethyldithiocarbamate-copper complex (CuET) inhibits colorectal cancer progression via miR-16-5p and 15b-5p/ALDH1A3/PKM2 axis-mediated aerobic glycolysis pathway.

Exploring novel anticancer drugs to optimize the efficacy may provide a benefit for the treatment of colorectal cancer (CRC). Disulfiram (DSF), as an antialcoholism drug, is metabolized into diethyldithiocarbamate-copper complex (CuET) in vivo, which has been reported to exert the anticancer effects on various tumors in preclinical studies. However, little is known about whether CuET plays an anti-cancer role in CRC. In this study, we found that CuET had a marked effect on suppressing CRC progression both in vitro and in vivo by reducing glucose metabolism. Mechanistically, using RNA-seq analysis, we identified ALDH1A3 as a target gene of CuET, which promoted cell viability and the capacity of clonal formation and inhibited apoptosis in CRC cells. MicroRNA (miR)-16-5p and 15b-5p were shown to synergistically regulate ALDH1A3, which was negatively correlated with both of them and inversely correlated with the survival of CRC patients. Notably, using co-immunoprecipitation followed with mass spectrometry assays, we identified PKM2 as a direct downstream effector of ALDH1A3 that stabilized PKM2 by reducing ubiquitination. Taken together, we disclose that CuET treatment plays an active role in inhibiting CRC progression via miR-16-5p and 15b-5p/ALDH1A3/PKM2 axis-mediated aerobic glycolysis pathway.

LINC00675 activates androgen receptor axis signaling pathway to promote castration-resistant prostate cancer progression.

The development of prostate cancer (PCa) from androgen-deprivation therapy (ADT) sensitive to castration resistant (CRPC) seriously impacts life quality and survival of PCa patients. Emerging evidence shows that long noncoding RNAs (lncRNAs) play vital roles in cancer initiation and progression. However, the inherited mechanisms of how lncRNAs participate in PCa progression and treatment resistance remain unclear. Here, we found that a long noncoding RNA LINC00675 was upregulated in androgen-insensitive PCa cell lines and CRPC patients, which promoted PCa progression both in vitro and in vivo. Knockdown of LINC00675 markedly suppressed tumor formation and attenuated enzalutamide resistance of PCa cells. Mechanistically, LINC00675 could directly modulate androgen receptor's (AR) interaction with mouse double minute-2 (MDM2) and block AR's ubiquitination by binding to it. Meanwhile, LINC00675 could bind to GATA2 mRNA and stabilize its expression level, in which GATA2 could act as a co-activator in the AR signaling pathway. Notably, we treated subcutaneous xenografts models with enzalutamide and antisense oligonucleotides (ASO) targeting LINC00675 in vivo and found that targeting LINC00675 would benefit androgen-deprivation-insensitive models. Our findings disclose that the LINC00675/MDM2/GATA2/AR signaling axis is a potential therapeutic target for CRPC patients.

Correction: LRP6 promotes invasion and metastasis of colorectal cancer through cytoskeleton dynamics.

[This corrects the article DOI: 10.18632/oncotarget.22759.].

Correction to: Remodelin, an inhibitor of NAT10, could suppress hypoxia-induced or constitutional expression of HIFs in cells.

The article "Remodelin, an inhibitor of NAT10, could suppress hypoxia-induced or constitutional expression of HIFs in cells", written by "Yaqian Wu, Yanan Cao, Haijing Liu, Mengfei Yao, Ningning Ma and Bo Zhang", was originally published electronically on the publisher's internet portal https://link.springer.com/article/10.1007/s11010-020-03776-w on 11 June 2020 with open access. With the author(s)' decision to step back from Open Choice, the copyright of the article changed on 6 July 2020 to © Springer Science+Business Media, LLC, part of Springer Nature 2020 and the article is forthwith distributed under the terms of copyright. The original article has been corrected.

Remodelin, an inhibitor of NAT10, could suppress hypoxia-induced or constitutional expression of HIFs in cells.

Hypoxia-inducible factors (HIFs) are key mediators expressed under hypoxic condition and involved in many kinds of disease such as cancer and abnormal angiogenesis. Thus, development of their inhibitor has been extensively explored. Here, we describe a finding that Remodelin, a specific inhibitor of NAT10, could also inhibit the expression of HIFs. The presence of Remodelin could suppress the elevated level of HIF-1α protein and its nuclear translocation induced by either treatment of cobalt chloride (CoCl2) or hypoxia in dose or time-dependent way. More importantly, Remodelin could also inhibit the constitutional expression of HIF-1α and HIF-2α in VHL mutant 786-0 cells. With using of cells with depletion of NAT10 by shRNA or Crispr-Cas9 edited, we further demonstrated that inhibition of HIFs by Remodelin should need NAT10 activity. In biological analysis, the treatment of cultured HUVECs with Remodelin could inhibit in vitro cell migration and invasion and tube-formation. Our investigation implied that Remodelin could be a new potential inhibitor of HIFs for using in angiogenesis targeting therapy in either cancers or inflammatory diseases.

N-Acetyltransferase 10 Promotes Micronuclei Formation to Activate the Senescence-Associated Secretory Phenotype Machinery in Colorectal Cancer Cells.

The formation of micronuclei (MN) is prevalent in human cancer cells and its role in activating the senescence-associated secretory phenotype (SASP) machinery has been identified recently. However, the role of MN in regulation of SASP signaling still needs to define in practical cancers. Here, we reported that in colorectal cancer cells the expression of NAT10 (N-acetyltransferase 10) could mediate MN formation through DNA replication and NAT10-positive MN could activate SASP by binding to cGAS. The chemical inhibition of NAT10 by Remodelin or genomic depletion could markedly reduce MN formation, SASP activation, and senescence in colorectal cancer cells. Cell stress such as oxidative or hypoxia could upregulate NAT10 and its associated MN formation senescence and expression of SASP factors. Statistical analysis of clinical specimens revealed correlations between NAT10 expression, MN formation, SASP signaling, and the clinicopathological features of colorectal cancer. Our data suggest that NAT10 increasing MN formation and SASP pathway activation, promoting colorectal cancer progression.

Dichloroacetate restores colorectal cancer chemosensitivity through the p53/miR-149-3p/PDK2-mediated glucose metabolic pathway.

The development of chemoresistance remains a major challenge that accounts for colorectal cancer (CRC) lethality. Dichloroacetate (DCA) was originally used as a metabolic regulator in the treatment of metabolic diseases; here, DCA was assayed to identify the mechanisms underlying the chemoresistance of CRC. We found that DCA markedly enhanced chemosensitivity of CRC cells to fluorouracil (5-FU), and reduced the colony formation due to high levels of apoptosis. Using the microarray assay, we noted that miR-149-3p was involved in the chemoresistance of CRC, which was modulated by wild-type p53 after DCA treatment. In addition, PDK2 was identified as a direct target of miR-149-3p. Mechanistic analyses showed that overexpression of miR-149-3p enhanced 5-FU-induced apoptosis and reduced glucose metabolism, similar to the effects of PDK2 knockdown. In addition, overexpression of PDK2 partially reversed the inhibitory effect of miR-149-3p on glucose metabolism. Finally, both DCA treatment and miR-149-3p overexpression in 5-FU-resistant CRC cells were found to markedly sensitize the chemotherapeutic effect of 5-FU in vivo, and this effect was also validated in a small retrospective cohort of CRC patients. Taken together, we determined that the p53/miR-149-3p/PDK2 signaling pathway can potentially be targeted with DCA treatment to overcome chemoresistant CRC.

Dichloroacetate Overcomes Oxaliplatin Chemoresistance in Colorectal Cancer through the miR-543/PTEN/Akt/mTOR Pathway.

Chemoresistance is responsible for most colorectal cancer (CRC) related deaths. In this study, we found that dichloroacetate (DCA), a pyruvate dehydrogenase kinase (PDK) inhibitor, can be used as a sensitizer for oxaliplatin (L-OHP) chemoresistant CRC cells. The aim of this study was to explore the ability of DCA to overcome L-OHP resistance in CRC cells and to identify the underlying molecular mechanisms. We found that DCA sensitizes chemoresistant CRC cells to L-OHP-induced cytotoxic effects by inhibiting clone formation capacity and promoting cell apoptosis. A microRNA (miRNA) array was used for screen, and miR-543 was identified and shown to be downregulated after DCA treatment. The expression of miR-543 was higher in chemoresistant CRC cells than in chemosensitive CRC cells. Overexpression of miR-543 increased chemoresistance in CRC cells. The validated target gene, PTEN, was negatively regulated by miR-543 both in vitro and in vivo, and PTEN was upregulated by DCA through miR-543. In addition, overexpression of miR-543 reversed the inhibition of colony formation after DCA treatment. Furthermore, the Akt/mTOR pathway is activated by miR-543 and is involved in the miR-543 induced chemoresistance. There was a significant inverse relationship between miR-543 expression and PTEN level in CRC patients, and high miR-543 expression was associated with worse prognosis. In conclusion, DCA restored chemosensitivity through miR-543/PTEN/Akt/mTOR pathway, and miR-543 may be a potential marker or therapeutic target for chemoresistance in CRC.