MTA1 localizes to the mitotic spindle apparatus and interacts with TPR in spindle assembly checkpoint regulation.

We previously identified a cell cycle-dependent periodic subcellular distribution of cancer metastasis-associated antigen 1 (MTA1) and unraveled a novel role of MTA1 in inhibiting spindle damage-induced spindle assembly checkpoint (SAC) activation in cancer cells. However, the more detailed subcellular localization of MTA1 in mitotic cells and its copartner in SAC regulation in cancer cells are still poorly understood. Here, through immunofluorescent colocalization analysis of MTA1 and alpha-tubulin in mitotic cancer cells, we reveal that MTA1 is dynamically localized to the spindle apparatus throughout the entire mitotic process. We also demonstrated a reversible upregulation of MTA1 expression upon spindle damage-induced SAC activation, and time-lapse imaging assays indicated that MTA1 silencing delayed the mitotic metaphase-anaphase transition in cancer cells. Further investigation revealed that MTA1 interacts and colocalizes with Translocated Promoter Region (TPR) on spindle microtubules in mitotic cells, and this interaction is attenuated on SAC activation. TPR is well-implicated in SAC regulation via binding the MAD1-MAD2 complex, however, no interactions between MTA1 and MAD1 or MAD2 were detected in our coimmunoprecipitation (co-IP) assays, suggesting that the MTA1-TPR may represent a distinct SAC-associated complex separate from the previously reported TPR-MAD1/MAD2 complex. Our data provide new insights into the subcellular localization and molecular function of MTA1 in SAC regulation in cancer, and indicate that intervention of the MTA1-TPR interaction may be effective to modulate SAC and hence chromosomal instability (CIN) in tumorigenesis.

MTA1, a Novel ATP Synthase Complex Modulator, Enhances Colon Cancer Liver Metastasis by Driving Mitochondrial Metabolism Reprogramming.

Liver metastasis is the most fatal event of colon cancer patients. Warburg effect has been long challenged by the fact of upregulated oxidative phosphorylation (OXPHOS), while its mechanism remains unclear. Here, metastasis-associated antigen 1 (MTA1) is identified as a newly identified adenosine triphosphate (ATP) synthase modulator by interacting with ATP synthase F1 subunit alpha (ATP5A), facilitates colon cancer liver metastasis by driving mitochondrial bioenergetic metabolism reprogramming, enhancing OXPHOS; therefore, modulating ATP synthase activity and downstream mTOR pathways. High-throughput screening of an anticancer drug shows MTA1 knockout increases the sensitivity of colon cancer to mitochondrial bioenergetic metabolism-targeted drugs and mTOR inhibitors. Inhibiting ATP5A enhances the sensitivity of liver-metastasized colon cancer to sirolimus in an MTA1-dependent manner. The therapeutic effects are verified in xenograft models and clinical cases. This research identifies a new modulator of mitochondrial bioenergetic reprogramming in cancer metastasis and reveals a new mechanism on upregulating mitochondrial OXPHOS as the reversal of Warburg effect in cancer metastasis is orchestrated.

The Biological Characteristics of Eutopic and Ectopic Endometrial Progenitor Cells in Endometriosis.

AIM: The aim of this study was to identify the biological characteristics and potential roles of endometrial progenitor cells in the pathogenesis of endometriosis. BACKGROUND: It is generally believed that progenitor cells in human endometrium are responsible for rapid endometrial regeneration. However, the biological characteristics and potential roles of the paired eutopic and ectopic endometrial progenitor cells in endometriosis remain unclear. OBJECTIVE: This study intends to isolate the epithelial progenitor (EP) cells and endometrial mesenchymal stem cells (eMSCs) from the eutopic and ectopic endometria from endometriosis patients, further to reveal their features and functions respectively. METHODS: The distributions of EP cells and eMSCs and the expression of steroid hormone receptors in the endometrium and endometriotic tissues were assessed by immunohistochemistry. EP cells and eMSCs were sorted from paired eutopic and ectopic endometria with epithelial cell adhesion molecule (EpCAM) magnetic beads. The clonogenicity, cell viability after being treated with estradiol and progesterone, and cell markers expression were evaluated with colony forming on Matrigel, CCK-8 and immunofluorescence staining, respectively. The differentially expressed genes (DEGs) were further identified with RNA sequencing. RESULTS: SSEA-1- and PDGFRß-positive cells were distributed in the epithelial and stromal layers. The ERß staining was much more intense in endometriotic tissues, but PR expression was almost absent. The ectopic EP cells exhibit strong clonogenicity and ERß expression but weak PR expression, leading to progesterone resistance. There are 12604 and 13242 DEGs revealed by RNA sequencing between eutopic and ectopic EP cells or eMSCs. GO and KEGG analyses revealed that the functions and pathways of DEGs enriched in cellular energy metabolism and regulation of the immune response, respectively. Additionally, ERß targets were mainly enriched in ectopic EP cells. CONCLUSION: Both EP cells and eMSCs may engage in ectopic lesion formation in endometriosis by modifying the metabolic mode and immune tolerance. These data not only help to understand the molecular mechanism of endometriosis but also could potentially contribute to the discovery of therapeutic targets for endometriosis.

Dachaihu decoction inhibits hypernutrition-induced liver metastasis from colorectal cancer by maintaining the gut vascular barrier.

Background: Colorectal cancer (CRC) is the third most common malignancy and the second deadliest cancer worldwide. Metastasis to the liver, the most common metastatic site in CRC, is the leading cause of death in patients with CRC. Hyperlipidemia, which is common in patients with CRC, promotes CRC progression and metastasis. Hyperlipidemia is commonly observed in obese patients and is often induced by hypernutrition. The underlying mechanism of hypernutrition-induced hyperlipidemia in promoting CRC liver metastasis remains unclear, and there is an unmet need for effective and low-cost treatments for patients with CRC. Methods: A mouse cecum orthotopic CRC model combined with high-fat diet (HFD) feeding, was established to mimic liver metastasis in CRC in obese patients. The effects of Dachaihu decoction (DCHD), a traditional herbal medicine used to treat inflammation and nonalcoholic fatty liver disease, and of the conventional prescription medicine obeticholic acid (OCA) were evaluated. HFD-induced obesity, hyperlipidemia, and CRC liver metastasis were assessed, along with the histology and pathology of the liver and intestine and the expression of metabolic genes in these tissues. The effects of DCHD and OCA on HFD-induced outcomes were evaluated, and human umbilical vein endothelial cells (HUVECs) treated with bile acids (BAs) and DCHD were used to study the underlying mechanisms in vitro. Results: HFD-mediated obesity and hyperlipidemia promoted CRC metastasis, accompanied by disruption of the gut vascular barrier (GVB) and altered bile acid (BA) metabolism. DCHD decreased HFD-induced hyperlipidemia and liver metastasis in CRC, improving overall survival. Those effects of DCHD were equivalent to or better than those of OCA. DCHD regulated the expression of genes of BA metabolism and tight junctions (TJ) to prevent HFD-induced disruption of the GVB. In HUVECs, DCHD prevented the increases in intracellular Ca2+ and accumulation of reactive oxygen species induced by primary conjugated BAs, assisting in the maintenance of redox homeostasis and preventing the downregulation of TJ proteins, thereby maintaining the integrity of the endothelial barrier. Conclusions: The data provide a link between hypernutrition and GVB disruption, which contributes to high liver metastasis in patients with CRC. DCHD may represent a novel therapy in CRC, and targeting abnormal lipid metabolism could be a promising therapeutic strategy for avoiding hypernutrition-associated CRC metastasis.

Expression dynamics of periodic transcripts during cancer cell cycle progression and their correlation with anticancer drug sensitivity.

BACKGROUND: The cell cycle is at the center of cellular activities and is orchestrated by complex regulatory mechanisms, among which transcriptional regulation is one of the most important components. Alternative splicing dramatically expands the regulatory network by producing transcript isoforms of genes to exquisitely control the cell cycle. However, the patterns of transcript isoform expression in the cell cycle are unclear. Therapies targeting cell cycle checkpoints are commonly used as anticancer therapies, but none of them have been designed or evaluated at the alternative splicing transcript level. The utility of these transcripts as markers of cell cycle-related drug sensitivity is still unknown, and studies on the expression patterns of cell cycle-targeting drug-related transcripts are also rare. METHODS: To explore alternative splicing patterns during cell cycle progression, we performed sequential transcriptomic assays following cell cycle synchronization in colon cancer HCT116 and breast cancer MDA-MB-231 cell lines, using flow cytometry and reference cell cycle transcripts to confirm the cell cycle phases of samples, and we developed a new algorithm to describe the periodic patterns of transcripts fluctuating during the cell cycle. Genomics of Drug Sensitivity in Cancer (GDSC) drug sensitivity datasets and Cancer Cell Line Encyclopedia (CCLE) transcript datasets were used to assess the correlation of genes and their transcript isoforms with drug sensitivity. We identified transcripts associated with typical drugs targeting cell cycle by determining correlation coefficients. Cytotoxicity assays were used to confirm the effect of ENST00000257904 against cyclin dependent kinase 4/6 (CDK4/6) inhibitors. Finally, alternative splicing transcripts associated with mitotic (M) phase arrest were analyzed using an RNA synthesis inhibition assay and transcriptome analysis. RESULTS: We established high-resolution transcriptome datasets of synchronized cell cycle samples from colon cancer HCT116 and breast cancer MDA-MB-231 cells. The results of the cell cycle assessment showed that 43,326, 41,578 and 29,244 transcripts were found to be periodically expressed in HeLa, HCT116 and MDA-MB-231 cells, respectively, among which 1280 transcripts showed this expression pattern in all three cancer cell lines. Drug sensitivity assessments showed that a large number of these transcripts displayed a higher correlation with drug sensitivity than their corresponding genes. Cell cycle-related drug screening showed that the level of the CDK4 transcript ENST00000547281 was more significantly associated with the resistance of cells to CDK4/6 inhibitors than the level of the CDK4 reference transcript ENST00000257904. The transcriptional inhibition assay following M phase arrest further confirmed the M-phase-specific expression of the splicing transcripts. Combined with the cell cycle-related drug screening, the results also showed that a set of periodic transcripts, for example, ENST00000314392 (a dolichyl-phosphate mannosyltransferase polypeptide 2 isoform transcript), was more associated with drug sensitivity than the levels of their corresponding gene transcripts. CONCLUSIONS: In summary, we identified a panel of cell cycle-related periodic transcripts and found that the levels of transcripts of drug target genes showed different values for predicting drug sensitivity, providing novel insights into alternative splicing-related drug development and evaluation.

Synergism between the metabolic syndrome components and cancer incidence: results from a prospective nested case-control study based on the China Health and Retirement Longitudinal Study (CHARLS).

OBJECTIVES: Synergism between the metabolic syndrome (MetSyn) components and cancer incidence still remains inconclusive. We aimed to investigate the unique or joint role of MetSyn components in cancer onset. DESIGN: We conducted a prospective nested case-control study based on the China Health and Retirement Longitudinal Study. SETTING: An ongoing national representative longitudinal study included follow-up survey of people aged 45 years and older and their partners living in private households in China. PARTICIPANTS: There were 17 708 individuals included at baseline. A total of 306 incident cancers was identified during the follow-up. For every case, we used incidence-density sampling to match three concurrent cancer-free controls by age, sex, and both duration and calendar time of follow-up. Exposure of interest was any MetSyn diagnosis at baseline. RESULTS: We observed elevation in cancer risk associated with MetSyn in a significant way when the number of MetSyn components was over three (OR: 1.88; 95% CI: 1.19 to 2.97), or when components contained any of elevated triglycerides (OR: 1.61; 95% CI: 1.05 to 2.48), reduced high-density lipoprotein (HDL) cholesterol (OR: 2.33; 95% CI: 1.40 to 3.86) or elevated blood pressure (OR: 1.65; 95% CI: 1.04 to 2.59) after consistent multiple adjustments in different models. The highest cancer risk was in the female reproductive system and breast cancer (OR: 4.22; 95% CI: 1.62 to 10.95) followed by digestive system (OR: 1.67; 95% CI: 1.11 to 2.53). Sensitivity analyses showed similar results after first follow-up was excluded. However, any unique MetSyn component was not associated with increased cancer risk. Interestingly, the reduced HDL was observed to be widely associated with over twofold increased risk of cancer, only when together with other MetSyn components. CONCLUSION: MetSyn components, in a collaborative manner rather than its unique component, were associated with elevated cancer risk. Not only obesity but even subtle metabolic disturbances may give rise to cancer.

Comparing Long-Term Survival Outcomes for Muscle-Invasive Bladder Cancer Patients Who Underwent with Radical Cystectomy and Bladder-Sparing Trimodality Therapy: A Multicentre Cohort Analysis.

Background: Although radical cystectomy (RC) is the clinical practice guideline-recommended treatment of muscle-invasive bladder cancer (MIBC), bladder-sparing trimodality therapy (TMT) has emerged as a valid treatment option. Findings comparing the survival outcomes for MIBC patients who underwent RC and TMT are inconclusive. Objective: We designed a large hospital-based multicohort study to compare the effectiveness of TMT with RC. Methods: Information on deaths was jointly retrieved from EMR (electronic medical record), cause of death registry, and chronic disease surveillance as well as study-specific questionnaire. To avoid the systematical difference between patients who received two modalities, RC-MIBC cohort was propensity score-matched to TMT-MIBC cohort, and the Cox proportional hazard regression was used to calculate the overall survival (OS) and disease-specific survival (DSS). Results: There were 891 MIBC patients treated with RC and another 891 MIBC patients who underwent with TMT in the propensity score matching. Comparable effectiveness between two modalities was observed for DSS (HR, 1.20; 95% confidence interval (CI), 0.94 to 1.49) and OS (HR, 1.17; 95% CI, 0.91 to 1.43) according to multiple adjustment after a median follow-up of approximately 9.3 years. However, a relatively higher mortality rate around 5 years after TMT treatment was found compared to RC (HR, 1.26; 95% CI, 1.01 to 1.53). The respective 5-year OS rates were 69% and 73% for TMT cohort and RC cohort, respectively. Conclusions: Our findings supported that MIBC patients with TMT yielded survival outcomes comparable to MIBC patients who underwent RC overall. Treatment options should be suggested considering patients' age and willingness.

Upregulation of MTA1 in Colon Cancer Drives A CD8+ T Cell-Rich But Classical Macrophage-Lacking Immunosuppressive Tumor Microenvironment.

Background: The MTA1 protein encoded by metastasis-associated protein 1 (MTA1) is a key component of the ATP-dependent nucleosome remodeling and deacetylase (NuRD) complex, which is widely upregulated in cancers. MTA1 extensively affects downstream gene expression by participating in chromatin remodeling. Although it was defined as a metastasis-associated gene in first reports and metastasis is a process prominently affected by the tumor microenvironment, whether it affects the microenvironment has not been investigated. In our study, we elucidated the regulatory effect of MTA1 on tumor-associated macrophages (TAMs) and how this regulation affects the antitumor effect of cytotoxic T lymphocytes (CTLs) in the tumor microenvironment of colorectal cancer. Methods: We detected the cytokines affected by MTA1 expression via a cytokine antibody array in control HCT116 cells and HCT116 cells overexpressing MTA1. Multiplex IHC staining was conducted on a colorectal cancer tissue array from our cancer cohort. Flow cytometry (FCM) was performed to explore the polarization of macrophages in the coculture system and the antitumor killing effect of CTLs in the coculture system. Bioinformatics analysis was conducted to analyze the Cancer Genome Atlas (TCGA) colorectal cancer cohort and single-cell RNA-seq data to assess the immune infiltration status of the TCGA colorectal cancer cohort and the functions of myeloid cells. Results: MTA1 upregulation in colorectal cancer was found to drive an immunosuppressive tumor microenvironment. In the tumor microenvironment of MTA1-upregulated colorectal cancer, although CD8+ T cells were significantly enriched, macrophages were significantly decreased, which impaired the CTL effect of the CD8+ T cells on tumor cells. Moreover, upregulated MTA1 in tumor cells significantly induced infiltrated macrophages into tumor-associated macrophage phenotypes and further weakened the cytotoxic effect of CD8+ T cells. Conclusion: Upregulation of MTA1 in colorectal cancer drives an immunosuppressive tumor microenvironment by decreasing the microphages from the tumor and inducing the residual macrophages into tumor-associated microphage phenotypes to block the activation of the killing CTL, which contributes to cancer progression.

Hormone replacement therapy in relation to the risk of colorectal cancer in women by BMI: a multicentre study with propensity score matching.

BACKGROUND: Epidemiological evidence about hormone replacement therapy and colorectal carcinogenesis by demographic and clinical traits remains unclear. We aimed to assess this postulated association in a large multicentre study and further explore the modification effect by BMI and others. METHODS: We retrospectively collected records of women diagnosed with colorectal cancer (CRC) at the age of 50 years and older during 2014-2017 and their HRT dispensing prior to CRC diagnosis in three tertiary hospitals in China. CRC cases were matched with controls at a ratio of 1:3 using nearest neighbour propensity scores matching to better control for the remaining imbalance between groups, which generated a total of 824 cases with 2472 controls. RESULTS: Our study confirmed the inversed association between colorectal cancer risk and hormone replacement therapy (OR, 0.62; 95% CI, 0.54-0.75), which was more prominent among women having multiple HRT dispenses (OR, 0.60; 95% CI, 0.52-0.76). Furthermore, significant associations were consistently observed for the short-term (OR, 0.69; 95% CI, 0.57-0.88), middle-term (OR, 0.51; 95% CI, 0.41-0.66), and long-term HRT users (OR, 0.70; 95% CI, 0.43-0.90). Estrogen-related regimen reduced CRC risk more than progestogen-only. We, for the first time, found that the modifying effect of BMI on HRT use and CRC risk was in different ways when BMI was categorized by a medium level of 27. CONCLUSION: Our findings mainly suggest that there might be a different mechanism for the reversed association between HRT and colorectal tumorigenesis by BMI level, providing thoughts on clinical treatment of CRC.

Inhibition of O-glycosylation aggravates GalN/LPS-induced liver injury through activation of ER stress.

OBJECTIVE: O-glycosylation is the most common post-translational modification of proteins, which is involved in many pathophysiological processes including inflammation. Acute liver injury is characterized by an excessive, uncontrolled inflammatory response, but the effects of aberrant O-glycosylation on acute liver injury are yet to explore. Here we aimed to investigate the role of defective O-glycosylation in D-galactosamine (GalN)/lipopolysaccharide (LPS)-induced acute liver damage in mice. MATERIAL AND METHODS: Experimental mice were administrated with an O-glycosylation inhibitor (benzyl-a-GalNac, 5 mg/kg) at 24 h before administration of GalN/LPS. At 12 h after GalN/LPS administration, mice were sacrificed to collect blood and liver samples for further analysis. RESULTS: We found that benzyl-a-GalNac treatment-induced abundant expression of Tn antigen, which is an immature O-glycan representing abnormal O-glycosylation. Benzyl-a-GalNac pretreatment exacerbated considerably GalN/LPS-induced liver damage in mice, evidenced by significantly reduced survival rates, more severe histological alterations, and notable elevation of multiple inflammatory cytokines and chemokines. Mechanistically, benzyl-a-GalNac could trigger endoplasmic reticulum (ER) stress in the liver of mice, demonstrated by the elevated expression of glucose-regulated protein 78 (GRP78) and C/EBP-homologous protein (CHOP), both of which are hallmarks for ER stress. Inhibition of ER stress by 4-phenylbutyric acid (4-PBA) markedly abrogated benzyl-a-GalNac-mediated enhanced hepatotoxicity and systemic inflammation in GalN/LPS-treated mice. CONCLUSIONS: This study demonstrated that inhibition of O-glycosylation caused by benzyl-a-GalNac aggravated GalN/LPS-induced liver damage and systemic inflammation, which may be due to activation of ER stress.

Gastric cancer with repeated metastasis in the colonic lumen: a case report and multi-surgical experience.

Poorly differentiated gastric adenocarcinoma is commonly associated with lymph node metastasis, peritoneal spread, and liver metastasis but rarely with intraintestinal metastasis. Most patients with metastatic gastric carcinoma are unable to undergo surgical treatment and have a poor prognosis. A 42-year-old man with hunger-related abdominal pain was diagnosed as having gastric cancer. After the first surgery (distal partial gastrectomy) and the second surgery (gastric stump carcinoma (GSC) resection), the patient suffered repeated multiple intracolonic metastases and underwent three additional resection operations. The patient survived for 154 months after the first operation. In patients with gastric carcinoma that metastasizes to the colonic lumen, radical resection, if possible, can extend survival. Once patients develop extensive extraintestinal metastasis, radical resection cannot be performed, and patients often exhibit a poor prognosis.

Circulating miR-449a predicts survival outcome for colorectal cancer following curative resection: An observational study.

ABSTRACT: Previous studies showed that microRNA (miR)-449a may function as a tumor suppressor. However, the expression pattern and value of circulating miR-449a in colorectal cancer (CRC) remain unclear. Therefore, the purpose of this study was to measure circulating miR-449a level of CRC patients and evaluate its value for predicting prognosis.Plasma samples of 343 consecutive CRC patients and 162 healthy controls were obtained. Circulating miR-449a levels were measured by using real-time quantitative reverse transcription polymerase chain reactions. All enrolled patients were followed up in a regular interval after surgery. The clinical data and survival outcome of all 343 patients were collected. The correlation between circulating miR-449a level and survival outcomes was analyzed by univariate and multivariate analysis.Circulating miR-449a level in CRC patients was significantly decreased (P < .05) comparing with healthy controls. Low miR-449a was significantly associated with CEA and CA19-9 level (both P < .05). Furthermore, patients with a decreased miR-449a level had a lower 5-years overall survival (OS) rate than those with a high miR-449a (67.4% vs 76.9%, P = .03). Low circulating miR-449a level also been demonstrated as an independent risk factor for CRC in multivariate COX analysis (HR, 2.56; 95%CI: 1.15-8.63; P < .05).Circulating miR-449a was significantly decreased in CRC patients and closely related to poor prognosis, suggesting that miR-449a might can be used as a useful diagnostic and prognostic marker for CRC.

CDC42EP3 promotes colorectal cancer through regulating cell proliferation, cell apoptosis and cell migration.

BACKGROUND: Nowadays, colorectal cancer (CRC) is one of the most commonly diagnosed malignant tumors worldwide, the incidence rate of which is still increasing year by year. Herein, the objective of this study is to investigate whether CDC42EP3 has regulatory effects in CRC. METHODS: First, CDC42EP3 knockdown cell model based on HCT116 and RKO cell lines was successfully constructed, which was further used for constructing mouse xenotransplantation models. Importantly, effects of CDC42EP3 knockdown on proliferation, colony formation, apoptosis, and migration of CRC were accessed by MTT assay, EdU staining assay, colony formation assay, Flow cytometry, and Transwell assay. RESULTS: As the results, we showed that CDC42EP3 was significantly upregulated in CRC, and its high expression was associated with tumor progression. Furthermore, knockdown of CDC42EP3 could inhibit proliferation, colony formation and migration, and promote apoptosis of CRC cells in vitro. In vivo results further confirmed knockdown of CDC42EP3 attenuated tumor growth in CRC. Interestingly, the regulation of CRC by CDC42EP3 involved not only the change of a variety of apoptosis-related proteins, but also the regulation of downstream signaling pathway. CONCLUSION: In conclusion, the role of CDC42EP3 in CRC was clarified and showed its potential as a target of innovative therapeutic approaches for CRC.

CDK12 inhibition enhances sensitivity of HER2+ breast cancers to HER2-tyrosine kinase inhibitor via suppressing PI3K/AKT.

BACKGROUND: Alhtough anti-HER2 tyrosine kinase inhibitors (TKIs) have radically prolonged survival and improved prognosis in HER2-positive breast cancer patients, resistance to these therapies is a constant obstacle leading to TKIs treatment failure and tumour progression. METHODS: To develop new strategies to enhance TKIs efficiency by combining synergistic gene targets, we performed panel library screening using the CRISPR/Cas9 knockout technique based on data mining across TCGA data sets and verified the candidate target in preclinical models and breast cancer high-throughput sequencing data sets. RESULTS: We identified that CDK12, co-amplified with HER2 in a high frequency, is powerful to sensitise or resensitise HER2-positive breast cancer to anti-HER2 TKIs lapatinib, evidenced by patient-derived organoids in vitro and cell-derived xenograft or patient-derived xenograft in vivo. Exploring mechanisms, we found that inhibition of CDK12 attenuated PI3K/AKT signal, which usually serves as an oncogenic driver and is reactivated when HER2-positive breast cancers develop resistance to lapatinib. Combining CDK12 inhibition exerted additional suppression on p-AKT activation induced by anti-HER2 TKIs lapatinib treatment. Clinically, via DNA sequencing data for tumour tissue and peripheral blood ctDNA, we found that HER2-positive breast cancer patients with CDK12 amplification responded more insensitively to anti-HER2 treatment than those without accompanying CDK12 amplification by harbouring a markedly shortened progression-free survival (PFS) (median PFS: 4.3 months versus 6.9 months; hazards ratio [HR] = 2.26 [95% confidence interval [CI] = 1.32-3.86]; P = 0.0028). CONCLUSIONS: Dual inhibition of HER2/CDK12 will prominently benefit the outcomes of patients with HER2-positive breast cancer by sensitising or resensitising the tumours to anti-HER2 TKIs treatment.

Chromatin modifier MTA1 regulates mitotic transition and tumorigenesis by orchestrating mitotic mRNA processing.

Dysregulated alternative splicing (AS) driving carcinogenetic mitosis remains poorly understood. Here, we demonstrate that cancer metastasis-associated antigen 1 (MTA1), a well-known oncogenic chromatin modifier, broadly interacts and co-expresses with RBPs across cancers, contributing to cancerous mitosis-related AS. Using developed fCLIP-seq technology, we show that MTA1 binds abundant transcripts, preferentially at splicing-responsible motifs, influencing the abundance and AS pattern of target transcripts. MTA1 regulates the mRNA level and guides the AS of a series of mitosis regulators. MTA1 deletion abrogated the dynamic AS switches of variants for ATRX and MYBL2 at mitotic stage, which are relevant to mitosis-related tumorigenesis. MTA1 dysfunction causes defective mitotic arrest, leads to aberrant chromosome segregation, and results in chromosomal instability (CIN), eventually contributing to tumorigenesis. Currently, little is known about the RNA splicing during mitosis; here, we uncover that MTA1 binds transcripts and orchestrates dynamic splicing of mitosis regulators in tumorigenesis.

MiR-362-3p is downregulated by promoter methylation and independently predicts shorter OS of cervical squamous cell carcinoma.

The current study was undertaken to investigate the potential influence of methylation on miR-362-5p/3p expression and further analyzed their independent prognostic value in cervical adenocarcinoma (ADC) and squamous cell carcinoma (SCC) respectively. SiHa and CaSki cells were used as the in vitro cell model. In silico bioinformatic analysis was conducted via the combined use of the Cancer Genome Atlas-Cervical Cancer (TCGA-CESC), Starbase 3.0 and String 10.5. Results revealed that the downregulation of miR-362-5p/3p was accompanied by the infection of high-risk human papillomavirus (HR-HPV) and their expression was further decreased in HR-HPV cancer tissues. Demethylation could restore their expression. By performing Methylation-specific PCR (MSP) based on methylated or unmethylated specific primers, we confirmed that the proximal promoter region was methylated in both cell lines. Higher miR-362-3p expression might independently predict favorable overall survival (OS) in SCC patients (HR: 0.561, 95%CI: 0.354-0.889, p = 0.014), after adjustment of clinical stages, lymphovascular invasion and miR-362-5p expression. However, no prognostic value of miR-362-5p or miR-362-3p expression was observed in terms of OS in patients with ADC. Via bioinformatic analysis, we found that miR-362-3p might have an entirely different regulatory network in cervical ADC and SCC, which might help to explain the distinct prognostic value of miR-362-3p in these two histological subtypes. In summary, we infer that the methylation level of the proximal promoter region of pre-miR-362 would influence the expression of miR-362-5p/3p in cervical cancer. MiR-362-3p expression might be a specific prognostic biomarker in cervical SCC, but not in ADC.

Preserved miR-361-3p Expression Is an Independent Prognostic Indicator of Favorable Survival in Cervical Cancer.

In this study, we aimed to assess the independent prognostic value of miR-361-3p in terms of overall survival (OS) and recurrence-free survival (RFS) in cervical cancer, as well as its possible regulative network. A retrospective analysis was performed by using data from the Cancer Genome Atlas-Cervical Cancer (TCGA-CESC). Results showed that decreased miR-361-3p expression was associated with lymphovascular invasion and poor responses to primary therapy. The patients with recurrence and the deceased cases had substantially lower miR-361-3p expression compared to their respective controls. By generating Kaplan-Meier curves of OS and RFS, we found that high miR-361-3p expression was associated with better survival outcome. More importantly, univariate and multivariate analysis confirmed that high miR-361-3p expression was an independent indicator of favorable OS (HR: 0.377, 95% CI: 0.233-0.608, p < 0.001) and RFS (HR: 0.398, 95% CI: 0.192-0.825, p = 0.013). By performing bioinformatic analysis, we identified 24 genes that were negatively correlated with miR-361-3p expression. Among the potential targeting genes, SOST, MTA1, TFRC, and YAP1 are involved in some important signaling pathways modulating cervical cancer cell invasion, migration, and drug sensitivity. Therefore, it is meaningful to verify the potential regulative effect of miR-361-3p on the expression of these genes in the future.

MiR-211 inhibits invasion and epithelial-to-mesenchymal transition (EMT) of cervical cancer cells via targeting MUC4.

The dysregulated molecules and their involvement in lymph node metastases of cervical cancer are far from been fully revealed. In this study, by reviewing MUC4 expression in The Human Protein Atlas and retrieving gene microarray data in GEO dataset (No. GDS4664), we found that MUC4 upregulation is associated with lymph node metastasis in cervical cancer. Knockdown of MUC4 in Hela and SiHa cells significantly reduced their invasion and also reduced the mesenchymal properties. By performing bioinformatics analysis, we observed that miR-211 is a potential suppressor of MUC4, which has a predicted highly conserved binding site in the 3'UTR of MUC among mammals. The following assays confirmed that miR-211 can directly target the 3'UTR of MUC4 and inhibit its expression at both mRNA and protein levels. In addition, enforced miR-211 expression phenocopies the effects of MUC4 siRNA in inhibiting cervical cancer cell invasion and reversing EMT properties. Therefore, we infer that miR-211 is a novel miRNA with suppressive effect on MUC4 expression and can inhibit cervical cancer cell invasion and EMT.

MiR-375 Is Epigenetically Downregulated by HPV-16 E6 Mediated DNMT1 Upregulation and Modulates EMT of Cervical Cancer Cells by Suppressing lncRNA MALAT1.

Epigenetic modulation is an important mechanism of miRNA dysregulation in cervical cancer. In this study, we firstly studied how this mechanism contributes to miR-375 downregulation in cervical cancer cells. Then, we further studied the association between miR-375 and MALAT1 (metastasis associated lung adenocarcinoma transcript 1) in epithelial mesenchymal transition (EMT) of the cancer cells. HPV-16 positive SiHa and CaSki cells were used as in vitro model. Our data showed that HPV-16 E6 positively modulated DNMT1 expression in both SiHa and CaSki cells. Knockdown of DNMT1 partly restored miR-375 levels in the cells. The following methylation-specific PCR (MSP) assay and qRT-PCR analysis showed that methylation was common in the promoter region of miR-375 in both SiHa and CaSki cells and demethylation partly restored miR-375 levels in the cells. Therefore, we infer that miR-375 is downregulated partly due to promoter hypermethylation mediated by DNMT1 in HPV-16 positive cervical cancer cells. Our bioinformatics analysis showed that MALAT1 has three putative binding sites with miR-375 and the following dual luciferase assay confirmed two of them. QRT-PCR analysis showed that miR-375 overexpression significantly reduced MALAT1 expression, while MALAT1 overexpression reversely suppressed miR-375 levels. Therefore, we infer that there is a reciprocal regulation between miR-375 and MALAT1 in the cells. In SiHa cells, miR-375 overexpression or MALAT1 siRNA partly restored E-cadherin expression, significantly reduced N-cadherin and also reduced invasion capacity of SiHa cells. Therefore, these results suggest that miR-375 and MALAT1 form a functional axis modulating EMT in cervical cancer.

MiR-21 modulates radiosensitivity of cervical cancer through inhibiting autophagy via the PTEN/Akt/HIF-1α feedback loop and the Akt-mTOR signaling pathway.

MiR-21 is an important microRNA (miRNA) modulating radiosensitivity of cervical cancer cells. However, the underlying mechanism of miR-21 upregulation in radioresistant cervical cancer has not been fully understood. In addition, autophagy may either promote or alleviate radioresistance, depending on the types of cancer and tumor microenvironment. How autophagy affects radiosensitivity in cervical cancer and how miR-21 is involved in this process has not been reported. This study showed that miR-21 upregulation in radioresistant cervical cancer is related to HIF-1α overexpression. MiR-21 overexpression decreases PTEN, increases p-Akt, and subsequently increases HIF-1α expression, while miR-21 inhibition results in increased PTEN, decreased p-Akt, and then decreased HIF-1α. Therefore, we inferred that there is a HIF-1α-miR-21 positive feedback loop through the PTEN/Akt/HIF-1α pathway in cervical cancer cells. In addition, we also demonstrated that miR-21 confers decreased autophagy in cervical cancer cells after IR via the Akt-mTOR signaling pathway. Decreased autophagy is one of the potential mechanisms of increased radioresistance in cervical cancer cells. These findings expand our understanding of radioresistance development in cervical cancer.