MTUS1 and its targeting miRNAs in colorectal carcinoma: significant associations

miR-135b: A key role in cancer biology and therapeutic targets

miR-135b, a microRNA, is consistently up-regulated in various cancer tissues and cells, promoting cancer progression. By inhibiting one or more target genes, miR-135b regulates phenotypes such as cancer growth, apoptosis, migration, invasion, drug resistance, and angiogenesis, establishing it as a critical driver of cancer progression. Additionally, miR-135b is regulated by various oncogenes and therapeutic drugs, highlighting its complexity and therapeutic potential. Significant progress has been made in understanding miR-135b's impact on cancer cell behavior, establishing it as a promising biomarker for cancer diagnosis and prognosis, as well as a potential target for future cancer therapies. However, despite the extensive research on this topic, there has been no comprehensive review summarizing its role and mechanisms across different cancer types. This review aims to provide a detailed overview of the biological characteristics of miR-135b, its regulatory targets, upstream signaling pathways, and its therapeutic potential, including its influence on cancer chemoresistance. The review also addresses key controversies surrounding miR-135b in cancer research, aiming to deepen the understanding of its role, promote the transformation of its clinical application, and provide a theoretical foundation for developing more effective cancer treatment strategies.

Four centrosome-related genes to predict the prognosis and drug sensitivity of patients with colon cancer

BACKGROUND

As the primary microtubule organizing center in animal cells, centrosome abnormalities are involved in human colon cancer.

AIM

To explore the role of centrosome-related genes (CRGs) in colon cancer.

METHODS

CRGs were collected from public databases. Consensus clustering analysis was performed to separate the Cancer Genome Atlas cohort. Univariate Cox and least absolute shrinkage selection operator regression analyses were performed to identify candidate prognostic CRGs and construct a centrosome-related signature (CRS) to score colon cancer patients. A nomogram was developed to evaluate the CRS risk in colon cancer patients. An integrated bioinformatics analysis was conducted to explore the correlation between the CRS and tumor immune microenvironment and response to immunotherapy, chemotherapy, and targeted therapy. Single-cell transcriptome analysis was conducted to examine the immune cell landscape of core prognostic genes.

RESULTS

A total of 726 CRGs were collected from public databases. A CRS was constructed, which consisted of the following four genes: TSC1, AXIN2, COPS7A, and MTUS1. Colon cancer patients with a high-risk signature had poor survival. Patients with a high-risk signature exhibited decreased levels of plasma cells and activated memory CD4+ T cells. Regarding treatment response, patients with a high-risk signature were resistant to immunotherapy, chemotherapy, and targeted therapy. COPS7A expression was relatively high in endothelial cells and fibroblasts. MTUS1 expression was high in endothelial cells, fibroblasts, and malignant cells.

CONCLUSION

We constructed a centrosome-related prognostic signature that can accurately predict the prognosis of colon cancer patients, contributing to the development of individualized treatment for colon cancer.

Cerebrospinal fluid exosomal microRNAs as biomarkers for diagnosing or monitoring the progression of non-small cell lung cancer with leptomeningeal metastases

Non-small-cell lung cancer (NSCLC) has a terrible consequence called leptomeningeal metastases (LM). It is crucial to look for novel biomarkers because none of the known biomarkers could effectively reflect the oncogenesis, progression and therapeutic responses of LM. Exosomal miRNAs from plasma have a critical function in lung cancer, according to growing data. However, unique biomarkers of cerebrospinal fluid (CSF) are more representative for patients with LM, which have not been reported. Here, we explore the possibility of using CSF-derived exosomal microRNAs as potential biomarkers for NSCLC-LM. Nine NSCLC-LM patients who received regular intrathecal chemotherapy with permetexed were divided into a partial response (PR) group and a progressive disease (PD) group. CSF samples were taken from all patients before and after intrathecal treatment and five non-cancerous controls. Using the size exclusion chromatography (SEC) method, the exosome microRNAs were isolated and profiled. Between LM patients and controls, 56 differentially expressed genes (DEGs) were found, of which three highly elevated diagnostic biomarkers (hsa-miR-183-5p, hsa-miR-96-5p and hsa-miR-182-5p) were ruled out. The two most significant DEGs between the untreated PR group and the PD group were determined to be upregulated hsa-miR-509-3p and downregulated hsa-miR-449a, and they may serve as potential indicators of intrathecal anti-pemetrexed treatment. Hsa-miR-1-3p increased gradually with the intrathecal chemotherapy in the PR group, which might offer a new approach to screen optimal patients and estimate the efficacy. This study revealed specific CSF exosomal miRNAs profile and dynamic changes of patients with NSCLC-LM for the first time and identified several potential exosomal miRNA biomarkers in diagnosis, drug resistance and prognosis.

Low MTUS1 Protein Expression Is Associated with Poor Survival in Patients with Colorectal Adenocarcinoma

Introduction: Microtubule-associated tumor suppressor 1 (MTUS1) is a novel tumor suppressor protein involved in cell proliferation, migration, and tumor growth. MTUS1 is thought to be downregulated in various human cancers and associated with poor prognosis. We evaluated the clinicopathologic significance and prognostic value of MTUS1 in colorectal adenocarcinoma. Methods: Immunohistochemical staining for MTUS1 was performed on tissue microarrays of 393 colorectal adenocarcinoma cases, and MTUS1 staining was classified into high- and low-expression groups. Then, we investigated the correlations between MTUS1 protein expression and various clinicopathological parameters and patient survival. Results: MTUS1 protein was expressed at various grade levels in the cytoplasm of tumor cells, which showed loss or decreased expression of MTUS1. A total of 253 cases (64.4%) were classified into the low MTUS1 protein expression group and 140 cases (35.6%) into the high MTUS1 expression group. A low level of MTUS1 protein significantly correlated with tumor size (p = 0.047), histological grade (p < 0.001), lymphovascular invasion (p < 0.001), perineural invasion (p = 0.047), and lymph node metastasis (p < 0.001). Survival analyses showed that patients with low MTUS1 protein expression had worse overall survival (p = 0.007, log-rank test) and worse recurrence-free survival (p = 0.019, log-rank test) than those with high MTUS1 expression. Conclusions: Low MTUS1 protein expression is associated with adverse clinicopathological characteristics and poor survival outcomes in patients with colorectal adenocarcinoma. These results suggest that MTUS1 functions as a tumor suppressor in colorectal adenocarcinoma and could be a potential prognostic biomarker.

Long Noncoding RNA MIR600HG Binds to MicroRNA-125a-5p to Prevent Pancreatic Cancer Progression Via Mitochondrial Tumor Suppressor 1-Dependent Suppression of Extracellular Regulated Protein Kinases Signaling Pathway

OBJECTIVES

Significance of long noncoding RNAs in pancreatic cancer (PC) progression has been documented. Here, we identified a novel long noncoding RNA MIR600HG in PC and its underlying mechanism during PC progression.

METHODS

Through bioinformatics analysis, we selected MIR600HG, microRNA-125a-5p (miR-125a-5p), and mitochondrial tumor suppressor 1 (MTUS1) as objects with their expression patterns assayed in the collected PC tissues and PC cells. Pancreatic cancer cells were manipulated with ectopic expression and deficiency of MIR600HG, miR-125a-5p, and/or MTUS1 for assaying cell biological processes in vitro and tumorigenesis in vivo.

RESULTS

MIR600HG and MTUS1 levels were downregulated and miR-125a-5p was upregulated in PC tissues and cells. MIR600HG could bind to miR-125a-5p, while miR-125a-5p negatively targeted MTUS1. MIR600HG resulted in suppression in malignant properties of PCs. All these changes could be reversed by miR-125a-5p elevation. In addition, miR-125a-5p targeted MTUS1 to activate the extracellular regulated protein kinases signaling pathway. In vivo experiment also verified the inhibitory role of MIR600HG in PC.

CONCLUSIONS

Taken together, MIR600HG acts as an inhibitor for PC progression by upregulating miR-125a-5p-mediated MTUS1 through extracellular regulated protein kinases pathway.

MTUS1 is a promising diagnostic and prognostic biomarker for colorectal cancer

BACKGROUND

The morbidity and mortality of colorectal cancer (CRC) remain high, posing a serious threat to human life and health. The early diagnosis and prognostic evaluation of CRC are two major challenges in clinical practice. MTUS1 is considered a tumour suppressor and can play an important role in inhibiting cell proliferation, migration, and tumour growth. Moreover, the expression of MTUS1 is decreased in different human cancers, including CRC. However, the biological functions and molecular mechanisms of MTUS1 in CRC remain unclear.

METHODS

In the present study, data from The Cancer Genome Atlas (TCGA) database were analysed using R statistical software (version 3.6.3.) to evaluate the expression of MTUS1 in tumour tissues and adjacent normal tissues using public databases such as the TIMER and Oncomine databases. Then, 38 clinical samples were collected, and qPCR was performed to verify MTUS1 expression. We also investigated the relationship between MTUS1 expression and clinicopathological characteristics and elucidated the diagnostic and prognostic value of MTUS1 in CRC. In addition, the correlation between MTUS1 expression and immune infiltration levels was identified using the TIMER and GEPIA databases. Furthermore, we constructed and analysed a PPI network and coexpression modules of MTUS1 to explore its molecular functions and mechanisms.

RESULTS

CRC tissues exhibited lower levels of MTUS1 than normal tissues. The logistic regression analysis indicated that the expression of MTUS1 was associated with N stage, TNM stage, and neoplasm type. Moreover, CRC patients with low MTUS1 expression had poor overall survival (OS). Multivariate analysis revealed that the downregulation of MTUS1 was an independent prognostic factor and was correlated with poor OS in CRC patients. MTUS1 expression had good diagnostic value based on ROC analysis. Furthermore, we identified a group of potential MTUS1-interacting proteins and coexpressed genes. GO and KEGG enrichment analyses showed that MTUS1 was involved in multiple cancer-related signalling pathways. Moreover, the expression of MTUS1 was significantly related to the infiltration levels of multiple cells. Finally, MTUS1 expression was strongly correlated with various immune marker sets.

CONCLUSIONS

Our results indicated that MTUS1 is a promising biomarker for predicting the diagnosis and prognosis of CRC patients. MTUS1 can also become a new molecular target for tumour immunotherapy.

Modular and mechanistic changes across stages of colorectal cancer

BACKGROUND

While mechanisms contributing to the progression and metastasis of colorectal cancer (CRC) are well studied, cancer stage-specific mechanisms have been less comprehensively explored. This is the focus of this manuscript.

METHODS

Using previously published data for CRC (Gene Expression Omnibus ID GSE21510), we identified differentially expressed genes (DEGs) across four stages of the disease. We then generated unweighted and weighted correlation networks for each of the stages. Communities within these networks were detected using the Louvain algorithm and topologically and functionally compared across stages using the normalized mutual information (NMI) metric and pathway enrichment analysis, respectively. We also used Short Time-series Expression Miner (STEM) algorithm to detect potential biomarkers having a role in CRC.

RESULTS

Sixteen Thousand Sixty Two DEGs were identified between various stages (p-value ≤ 0.05). Comparing communities of different stages revealed that neighboring stages were more similar to each other than non-neighboring stages, at both topological and functional levels. A functional analysis of 24 cancer-related pathways indicated that several signaling pathways were enriched across all stages. However, the stage-unique networks were distinctly enriched only for a subset of these 24 pathways (e.g., MAPK signaling pathway in stages I-III and Notch signaling pathway in stages III and IV). We identified potential biomarkers, including HOXB8 and WNT2 with increasing, and MTUS1 and SFRP2 with decreasing trends from stages I to IV. Extracting subnetworks of 10 cancer-relevant genes and their interacting first neighbors (162 genes in total) revealed that the connectivity patterns for these genes were different across stages. For example, BRAF and CDK4, members of the Ser/Thr kinase, up-regulated in cancer, displayed changing connectivity patterns from stages I to IV.

CONCLUSIONS

Here, we report molecular and modular networks for various stages of CRC, providing a pseudo-temporal view of the mechanistic changes associated with the disease. Our analysis highlighted similarities at both functional and topological levels, across stages. We further identified stage-specific mechanisms and biomarkers potentially contributing to the progression of CRC.

Mitochondrial Tumor Suppressors-The Energetic Enemies of Tumor Progression

Tumor suppressors represent a critical line of defense against tumorigenesis. Their mechanisms of action and the pathways they are involved in provide important insights into cancer progression, vulnerabilities, and treatment options. Although nuclear and cytosolic tumor suppressors have been extensively investigated, relatively little is known about tumor suppressors localized within the mitochondria. However, recent research has begun to uncover the roles of these important proteins in suppressing tumorigenesis. Here, we review this newly developing field and summarize available information on mitochondrial tumor suppressors.

Low-Level Expression of MTUS1 Is Associated with Poor Survival in Patients with Lung Adenocarcinoma

Microtubule-associated tumor suppressor 1 (MTUS1) is thought to be downregulated in arious human cancers, which suggests its role as a tumor suppressor. This study investigated the clinicopathological significance of MTUS1 expression in lung adenocarcinoma. Tissue microarray blocks consisting of 161 cases were constructed, and immunohistochemical staining was used to assess MTUS1 expression. Correlations of MTUS1 expression and clinicopathological parameters were analyzed. In addition, we used public databases and performed bioinformatics analysis. Low level of MTUS1 was significantly associated with higher clinical stage (p = 0.006), higher tumor stage (p = 0.044), lymph node metastasis (p = 0.01), worse histologic grade (p = 0.007), lymphovascular invasion (p = 0.014), and higher Ki-67 proliferation index (p < 0.001). Patients with low MTUS1 expression also showed shorter disease-free survival (p = 0.002) and cancer-specific survival (p = 0.006). Analysis of data from the Cancer Genome Atlas confirmed that the mRNA expression of MTUS1 in lung adenocarcinoma was significantly lower than that of normal lung tissue (p = 0.02), and patients with decreased MTUS1 expression showed significantly shorter overall survival (p = 0.008). These results suggest that MTUS1 may be a potential biomarker for predicting clinical outcomes in lung adenocarcinoma patients.

Biological differentiation of traditional Chinese medicine from excessive to deficient syndromes in AIDS: Comparative microRNA microarray profiling and syndrome-specific biomarker identification

Traditional Chinese medicine (TCM) has been widely applied as a supplementary therapy of human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) in China. TCM has a positive effect on improving the quality of life, prolonging life, and ameliorating the symptoms of HIV/AIDS patients. Yang deficiency of spleen and kidney (YDSK) syndrome is a typical deficient TCM syndrome in AIDS patients, and accumulation of heat-toxicity (AHT) syndrome is a common excessive syndrome in the earlier stage of AIDS. Thus, accurate diagnosis of these two syndromes can improve the targeted treatment effect, and predict the prognosis of the disease. However, the scientific basis of TCM syndromes remains lacking, greatly hindering the accuracy of diagnosis and effectiveness of treatment. In this research, microRNA (miRNA) microarray and quantitative real-time polymerase chain reaction combined with bioinformatics were used for comparative analysis between YDSK and AHT patients. Significantly differential expressed miRNAs (SDE-miRNAs) of each TCM syndrome were identified, including hsa-miR-766-3p and hsa-miR-1260a and so on, as well hsa-miR-6124, hsa-let-7g-5p and so on, for YDSK and AHT, respectively. Biological differences were found between their SDE-miRNAs based on bioinformatics analyses, for example, ErbB signaling pathway mainly linked to AHT, while focal adhesion dominated in YDSK. Syndrome-specific SDE-miRNAs were further identified as potential biomarkers, including hsa-miR-30e-5p, hsa-miR-144-5p for YDSK and hsa-let-7g-5p, hsa-miR-126-3p for AHT, respectively. All of them have laid biological and clinical bases for TCM diagnosis and treatment of AIDS syndrome at the miRNA level, offering potential diagnostic indicators of immune reconstitution.

Microtubule-Associated Protein ATIP3, an Emerging Target for Personalized Medicine in Breast Cancer

Breast cancer is the leading cause of death by malignancy among women worldwide. Clinical data and molecular characteristics of breast tumors are essential to guide clinician’s therapeutic decisions. In the new era of precision medicine, that aims at personalizing the treatment for each patient, there is urgent need to identify robust companion biomarkers for new targeted therapies. This review focuses on ATIP3, a potent anti-cancer protein encoded by candidate tumor suppressor gene MTUS1, whose expression levels are markedly down-regulated in breast cancer. ATIP3 is a microtubule-associated protein identified both as a prognostic biomarker of patient survival and a predictive biomarker of breast tumors response to taxane-based chemotherapy. We present here recent studies pointing out ATIP3 as an emerging anti-cancer protein and a potential companion biomarker to be combined with future personalized therapy against ATIP3-deficient breast cancer.

Anesthetics may modulate cancer surgical outcome: a possible role of miRNAs regulation

Background

microRNAs (miRNAs) are single-stranded and noncoding RNA molecules that control post-transcriptional gene regulation. miRNAs can be tumor suppressors or oncogenes through various mechanism including cancer cell biology, cell-to-cell communication, and anti-cancer immunity.

Main Body

Anesthetics can affect cell biology through miRNA-mediated regulation of messenger RNA (mRNA). Indeed, sevoflurane was reported to upregulate miR-203 and suppresses breast cancer cell proliferation. Propofol reduces matrix metalloproteinase expression through its impact on miRNAs, leading to anti-cancer microenvironmental changes. Propofol also modifies miRNA expression profile in circulating extracellular vesicles with their subsequent anti-cancer effects via modulating cell-to-cell communication.

Conclusion

Inhalational and intravenous anesthetics can alter cancer cell biology through various cellular signaling pathways induced by miRNAs’ modification. However, this area of research is insufficient and further study is needed to figure out optimal anesthesia regimens for cancer patients.

lncRNA LIFR‑AS1 inhibits gastric carcinoma cell proliferation, migration and invasion by sponging miR‑4698

The vital functions of long non‑coding (lnc)RNAs have been verified in gastric carcinoma (GC). However, as a novel cancer‑related lncRNA, the influence of leukemia inhibitory factor receptor antisense RNA 1 (LIFR‑AS1) in GC cell biological behaviors remains unreported. The present study explored the biological effects of lncRNA LIFR‑AS1 on GC progression. Reverse transcription‑quantitative PCR was performed to examine lncRNA LIFR‑AS1 expression in GC tissues and cells. Cell Counting Kit‑8, 5‑ethynyl‑2'‑deoxyuridine incorporation, cell wound healing and Transwell invasion assays were used to assess the functions of lncRNA LIFR‑AS1 in GC cell proliferation, migration and invasion. Additionally, associations among lncRNA LIFR‑AS1, microRNA (miR)‑4698 and microtubule‑associated tumor suppressor 1 (MTUS1) were investigated via bioinformatics software and a luciferase reporter system. In addition, western blotting was used to examine the expression of MEK and ERK. Decreased lncRNA LIFR‑AS1 expression was observed in GC tissues and cells. Upregulated lncRNA LIFR‑AS1 inhibited GC cell proliferation, migration and invasion. Upregulated miR‑4698 and downregulated MTUS1 were identified in GC tissues and cells. The inhibitory interaction between lncRNA LIFR‑AS1 and miR‑4698 was confirmed. Additionally, MTUS1 was predicted as a target gene of miR‑4698 positively regulated by lncRNA LIFR‑AS1. The MEK/ERK pathway was inhibited by lncRNA LIFR‑AS1 via regulating MTUS1. These findings revealed the inhibitory functions of lncRNA LIFR‑AS1 in GC cell proliferation, migration and invasion. The process was mediated via miR‑4698, MTUS1 and the MEK/ERK pathway.

Role of miRNAs in Sigmoid Colon Cancer: A Search for Potential Biomarkers

The aberrant expression of microRNAs in known to play a crucial role in carcinogenesis. Here, we evaluated the miRNA expression profile of sigmoid colon cancer (SCC) compared to adjacent-to-tumor (ADJ) and sigmoid colon healthy (SCH) tissues obtained from colon biopsy extracted from Brazilian patients. Comparisons were performed between each group separately, considering as significant p-values < 0.05 and |Log2(Fold-Change)| > 2. We found 20 differentially expressed miRNAs (DEmiRNAs) in all comparisons, two of which were shared between SCC vs. ADJ and SCC vs. SCH. We used miRTarBase, and miRTargetLink to identify target-genes of the differentially expressed miRNAs, and DAVID and REACTOME databases for gene enrichment analysis. We also used TCGA and GTEx databases to build miRNA-gene regulatory networks and check for the reproducibility in our results. As findings, in addition to previously known miRNAs associated with colorectal cancer, we identified three potential novel biomarkers. We showed that the three types of colon tissue could be clearly distinguished using a panel composed by the 20 DEmiRNAs. Additionally, we found enriched pathways related to the carcinogenic process in which miRNA could be involved, indicating that adjacent-to-tumor tissues may be already altered and cannot be considered as healthy tissues. Overall, we expect that these findings may help in the search for biomarkers to prevent cancer progression or, at least, allow its early detection, however, more studies are needed to confirm our results.

The Construction and Analysis of ceRNA Network and Patterns of Immune Infiltration in Colon Adenocarcinoma Metastasis

BACKGROUND

Colon adenocarcinoma (COAD) is a malignant and lethal tumor in digestive system and distance metastasis lead to poor prognosis. The metastasis-specific ceRNAs (competitive endogenous RNAs) and tumor-infiltrating immune cells might associate with tumor prognosis and distance metastasis. Nonetheless, few studies have concentrated on ceRNAs and Immune cells in COAD.

METHODS

The gene expression profile and clinical information of COAD were downloaded from TCGA and divided into two groups: primary tumors with or without distance metastasis. We applied comprehensive bioinformatics methods to analyze differential expression genes (DEGs) related to metastasis and establish the ceRNA networks. The Cox analysis and Lasso regression were utilized to screen the pivotal genes and prevent overfitting. Based on them, the prognosis prediction nomograms were established. The cell type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm was then applied to screen significant tumor immune-infiltrating cells associated with COAD metastasis and established another prognosis prediction model. Ultimately, co-expression analysis was applied to explore the relationship between key genes in ceRNA networks and significant immune cells. Multiple databases and preliminary clinical specimen validation were used to test the expressions of key biomarkers at the cellular and tissue levels.

RESULTS

We explored 1 significantly differentially expressed lncRNA, 1 significantly differentially expressed miRNA, 8 survival-related immune-infiltrating cells, 5 immune cells associated with distance metastasis. Besides, 3 pairs of important biomarkers associated with COAD metastasis were also identified: T cells follicular helper and hsa-miR-125b-5p (R = -0.200, P < 0.001), Macrophages M0 and hsa-miR-125b-5p (R = 0.170, P < 0.001) and Macrophages M0 and FAS (R = -0.370, P < 0.001). Multidimensional validation and preliminary clinical specimen validation also supported the results.

CONCLUSION

In this research, we found some significant ceRNAs (FAS and hsa-miR-125b-5p) and tumor-infiltrating immune cells (T cells follicular helper and Macrophages M0) might related to distance metastasis and prognosis of COAD. The nomograms could assist scientific and medical researchers in clinical management.

miRNAs-Based Molecular Signature for KRAS Mutated and Wild Type Colorectal Cancer: An Explorative Study

microRNAs (miRNAs) have been proposed as promising molecular biomarkers for diagnosis, prognosis, and responsive therapeutic targets in different types of cancer, including colorectal cancer (CRC). In this study, we evaluated the expression levels of 84 cancer-associated miRNAs in a cohort of 39 human samples comprising 13 peritumoral and 26 tumoral tissues from surgical specimens of CRC patients. KRAS mutations were detected in 11 tumoral samples. In a first analysis, we found 5 miRNAs (miR-215-5p, miR-9-5p, miR-138-5p, miR378a-3p, and miR-150-5p) that were significantly downregulated and one upregulated (miR-135b-5p) in tumoral tissues compared with the peritumoral tissues. Furthermore, by comparing miRNA profile between KRAS mutated CRC tissues respect to wild type CRC tissues, we found 7 miRNA (miR-27b-3p, miR-191-5p, miR-let7d-5p, miR-15b-5p, miR-98-5p, miR-10a-5p, and miR-149-5p) downregulated in KRAS mutated condition. In conclusion, we have identified a panel of miRNAs that specifically distinguish CRC tissues from peritumoral tissue and a different set of miRNAs specific for CRC with KRAS mutations. These findings may contribute to the discovering of new molecular biomarkers with clinic relevance and might shed light on novel molecular aspects of CRC.

Loss of MTUS1 Expression Is Associated With Poor Prognosis in Patients With Gallbladder Carcinoma

BACKGROUND/AIM

Microtubule-associated scaffold protein 1 (MTUS1) acts as tumor suppressor in several cancer types. This study assessed the relationship between clinicopathological characteristics and expression of microRNA candidates based on MTUS1 expression in gallbladder cancer (GBC).

MATERIALS AND METHODS

MTUS1 expression was evaluated by immunohistochemical staining of tissue microarrays from 109 cases of GBC. The association of MTUS1 expression with clinicopathological factors was explored. Two microRNA candidates (miR-19a-3p, and miR-19b-3p), which were identified by a literature review and computational analysis, were assessed in GBC tissue samples by quantitative real-time polymerase chain reaction.

RESULTS

Low MTUS1 expression in GBC was associated with high histological grade, perineural invasion, lymphovascular invasion, high T-stage, advanced TNM stage, poorer disease-free survival, and poorer cancer-specific survival. No statistical association between MTUS1 expression and expression of microRNA candidates was observed.

CONCLUSION

MTUS1 may act as tumor suppressor and might be a potential biomarker for predicting prognosis in GBC.

Silencing of microRNA-135b inhibits invasion, migration, and stemness of CD24+CD44+ pancreatic cancer stem cells through JADE-1-dependent AKT/mTOR pathway

Background

Recent studies have emphasized determining the ability of microRNAs (miRNAs) as crucial regulators in the occurrence and development of pancreatic cancer (PC), which continues to be one of the deadliest malignancies with few effective therapies. The study aimed to investigate the functional role of miR-135b and its associated mechanism to unravel the biological characteristics of tumor growth in pancreatic cancer stem cells (PCSCs).

Methods

Microarray analyses were initially performed to identify the PC-related miRNAs and genes. The expression of miR-135b and PCSC markers in PC tissues and cells was determined by RT-qPCR and western blot analysis, respectively. The potential gene (JADE-1) that could bind to miR-135b was confirmed by the dual-luciferase reporter assay. To investigate the tumorigenicity, migration, invasion, and stemness of PC cells, several gain-of-function and loss-of-function genetic experiments were conducted. Finally, tumor formation in nude mice was conducted to confirm the results in vivo.

Results

miR-135b was highly-expressed in PC tissues and PCSCs, which was identified to specifically target JADE-1. The overexpression of miR-135b promoted proliferation, migration, and invasion of PCSC, inhibited cell apoptosis and increased the expression of stemness-related factors (Sox-2, Oct-4, Nanog, Aldh1, and Slug). Moreover, miR-135b could promote the expression of phosphorylated AKT and phosphorylated mTOR in the AKT/mTOR pathway. Additionally, miR-135b overexpression accelerated tumor growth in nude mice.

Conclusions

Taken together, the silencing of miR-135b promotes the JADE-1 expression, which inactivates the AKT/mTOR pathway and ultimately results in inhibition of self-renewal and tumor growth of PCSCs. Hence, this study contributes to understanding the role of miR-135 in PCSCs and its underlying molecular mechanisms to aid in the development of effective PC therapeutics.

Focused screening reveals functional effects of microRNAs differentially expressed in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is still a leading cause of death worldwide. Recent studies have pointed to an important role of microRNAs in carcinogenesis. Several microRNAs are described as aberrantly expressed in CRC tissues and in the serum of patients. However, functional outcomes of microRNA aberrant expression still need to be explored at the cellular level. Here, we aimed to investigate the effects of microRNAs aberrantly expressed in CRC samples in the proliferation and cell death of a CRC cell line.

METHODS

We transfected 31 microRNA mimics into HCT116 cells. Total number of live propidium iodide negative (PI-) and dead (PI+) cells were measured 4 days post-transfection by using a high content screening (HCS) approach. HCS was further used to evaluate apoptosis (via Annexin V and PI staining), and to discern between intrinsic and extrinsic apoptotic pathways, by detecting cleaved Caspase 9 and 8, respectively. To reveal mRNA targets and potentially involved mechanisms, we performed microarray gene expression and functional pathway enrichment analysis. Quantitative PCR and western blot were used to validate potential mRNA targets.

RESULTS

Twenty microRNAs altered the proliferation of HCT116 cells in comparison to control. miR-22-3p, miR-24-3p, and miR-101-3p significantly repressed cell proliferation and induced cell death. Interestingly, all anti-proliferative microRNAs in our study had been previously described as poorly expressed in the CRC samples. Predicted miR-101-3p targets that were also downregulated by in our microarray were enriched for genes associated with Wnt and cancer pathways, including MCL-1, a member of the BCL-2 family, involved in apoptosis. Interestingly, miR-101-3p preferentially downregulated the long anti-apoptotic MCL-1 L isoform, and reduced cell survival specifically by activating the intrinsic apoptosis pathway. Moreover, miR-101-3p also downregulated IL6ST, STAT3A/B, and MYC mRNA levels, genes associated with stemness properties of CRC cells.

CONCLUSIONS

microRNAs upregulated in CRC tend to induce proliferation in vitro, whereas microRNAs poorly expressed in CRC halt proliferation and induce cell death. We provide novel evidence linking preferential inhibition of the anti-apoptotic MCL-1 L isoform by miR-101-3p and consequent activation of the intrinsic apoptotic pathway as potential mechanisms for its antitumoral activity, likely due to the inhibition of the IL-6/JAK/STAT signaling pathway.

The Efficacy of miR-20a as a Diagnostic and Prognostic Biomarker for Colorectal Cancer: A Systematic Review and Meta-Analysis

Background: MicroRNAs have altered expression levels in various diseases and may play an important role in the diagnosis and prognosis of colorectal cancer (CRC). Methods: We systemically reviewed and quantitatively synthesized the scientific evidence pertaining to microRNA-20a (miR-20a) as a CRC biomarker. A keyword and reference search in PubMed yielded 32 studies, in which miR-20a was measured in feces, serum, or tumor tissue. Data were extracted from a total of 5014 cancer cases and 2863 controls. Results: Twenty out of 21 relevant studies found that miR-20a was upregulated in CRC patients compared to controls. Meta-analysis revealed a pooled miR-20a fold change of 2.45 (95% CI: 2.24-2.66) in CRC patients versus controls. To estimate sensitivity and specificity of miR-20a as a diagnostic biomarker of CRC, a pooled area under the receiver operating characteristic curve (AUROC) was calculated (0.70, 95% CI: 0.63-0.78). The prognostic capacity of miR-20a was assessed using hazard ratios (HRs) for the overall survival (OS). The meta-analysis estimated the pooled HR for OS to be 2.02 (95% CI: 0.90-3.14) in CRC patients with high miR-20a expression. Conclusions: miR-20a may be a valid biomarker for CRC detection but may not be a strong predictor of poor prognosis in CRC.

Induction of microRNA‑let‑7a inhibits lung adenocarcinoma cell growth by regulating cyclin D1

Lung cancer is the most common cause of cancer‑associated mortality. MicroRNAs (miRNAs), as oncogenes or tumor suppressor genes, serve crucial roles not only in tumorigenesis, but also in tumor invasion and metastasis. Although miRNA‑let‑7a (let‑7a) has been reported to suppress cell growth in multiple cancer types, the biological mechanisms of let‑7a in lung adenocarcinoma are yet to be fully elucidated. In the present study, the molecular roles of let‑7a in lung adenocarcinoma were investigated by detecting its expression in lung adenocarcinoma tissues and exploring its roles in the regulation of lung cancer cell proliferation. Let‑7a expression was identified to be downregulated in lung adenocarcinoma tissues compared with normal tissues. Overexpression of let‑7a effectively suppressed cancer cell proliferation, migration and invasion in H1299 and A549 cells. Let‑7a also induced cell apoptosis and cell cycle arrest. Furthermore, let‑7a significantly inhibited cell growth by directly regulating cyclin D1 signals. This novel regulatory mechanism of let‑7a in lung adenocarcinoma provides possible avenues for future targeted therapies of lung cancer.

Let-7c inhibits cholangiocarcinoma growth but promotes tumor cell invasion and growth at extrahepatic sites

Cholangiocarcinoma (CCA) is a cancer type with high postoperative relapse rates and poor long-term survival largely due to tumor invasion, distant metastasis, and multidrug resistance. Deregulated microRNAs (miRNAs) are implicated in several cancer types including CCA. The specific roles of the miRNA let-7c in cholangiocarcinoma are not known and need to be further elucidated. In our translational study we show that microRNA let-7c expression was significantly downregulated in human cholangiocarcinoma tissues when compared to adjacent tissues of the same patient. Let-7c inhibited the tumorigenic properties of cholangiocarcinoma cells including their self-renewal capacity and sphere formation in vitro and subcutaneous cancer cell growth in vivo. Ectopic let-7c overexpression suppressed migration and invasion capacities of cholangiocarcinoma cell lines in vitro, however, promoted distant invasiveness in vivo. Furthermore, we found that let-7c regulated the aforementioned malignant biological properties, at least in part, through regulation of EZH2 protein expression and through the DVL3/β-catenin axis. The miRNA let-7c thus plays an important dual role in regulating tumorigenic and metastatic abilities of human cholangiocarcinoma through mechanisms involving EZH2 protein and the DVL3/β-catenin axis.

Changes in Blood microRNA Expression and Early Metabolic Responsiveness 21 Days Following Bariatric Surgery

Background: Early metabolic responses following bariatric surgery appear greater than expected given the initial weight loss and coincide with improvement in diabetes. We hypothesized that small non-coding microRNA changes might contribute to regulating mechanisms for metabolic changes and weight loss in patients with severe obesity and diabetes. Methods: Twenty-nine type 2 patients with severe obesity (mean BMI 46.2 kg/m²) and diabetes underwent Roux-en-Y gastric bypass (RYGB) surgery. Clinical measurements and fasting blood samples were taken preoperatively and at day 21 postoperatively. Normalization of fasting glucose and HbA1c following bariatric surgery (short-term diabetes remission) was defined as withdrawal of anti-diabetic medication and fasting glucose < 100 mg/dL (5.6 mmol/L) or HbA1c < 6.0%. MicroRNA expression was determined by quantitative polymerase chain reaction and tested for significant changes after surgery. Results: BMI decreased by 3.8 kg/m² 21 days postoperatively. Eighteen of 29 RYGB (62%) had short-term diabetes remission. Changes from pre- to post-surgery in 32 of 175 microRNAs were nominally significant (p < 0.05). Following multiple comparison adjustment, changes in seven microRNAs remained significant: miR-7-5p, let-7f-5p, miR-15b-5p, let-7i-5p, miR-320c, miR-205-5p, and miR-335-5p. Four pathways were over-represented by these seven microRNAs, including diabetes and insulin resistance pathways. Conclusion: Seven microRNAs showed significant changes 21 days after bariatric surgery. Functional pathways of the altered microRNAs were associated with diabetes-, pituitary-, and liver-related disease, with expression in natural killer cells, and pivotal intestinal pathology suggesting possible mechanistic roles in early diabetes responses following bariatric surgery.

MicroRNA-33a and let-7e inhibit human colorectal cancer progression by targeting ST8SIA1

Colorectal cancer (CRC) is one of the leading causes of cancer mortality worldwide. Aberrant sialylation is crucially involved in the progression of various types of cancer. MicroRNAs (miRNAs) have been broadly studied in cancer. MicroRNA-33a (miR-33a) and Has-let-7e (let-7e) are non-coding RNA that can reduce cell motility and viability in cancer. In this study, miR-33a and let-7e levels were confirmed to be significantly down-regulated in CRC samples (n=32) and drug resistant cell line (HCT-8/5-FU) compared with those in the matched adjacent tissues and drug sensitivity cell line (HCT-8). ST8SIA1 was highly expressed in CRC tissues and HCT-8/5-FU cells, which was negatively correlated with miR-33a/let-7e expression. Luciferase reporter assays confirmed that both miR-33a and let-7e bound to the 3'-untranslated (3'-UTR) region of ST8SIA1. Inhibiting miR-33a/let-7e expression in CRC cells increased endogenous ST8SIA1 mRNA and protein levels. MiR-33a/let-7e knockdown promoted chemoresistance, proliferation, invasion, angiogenesis in vitro, and tumor growth in vivo. Whereas, ectopic expression of miR-33a/let-7e suppressed chemoresistance, proliferation, invasion and angiogenesis in CRC cell lines. ST8SIA1 knockdown mimicked the tumor suppressive effect of miR-33a/let-7e on CRC cells, while restoration of ST8SIA1 abolished the tumor suppressive effect of miR-33a/let-7e on CRC cells. Taken together, altered expression of miR-33a/let-7e was correlated with ST8SIA1 level, which might contribute to CRC progression. The miR-33a/let-7e-ST8SIA1 axis could be a therapeutic target for CRC patients.

Overexpression of miR-135b-5p promotes unfavorable clinical characteristics and poor prognosis via the repression of SFRP4 in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and malignant neoplasm. The aberrant expression of miR-135b-5p and secreted frizzled-related protein 4 (SFRP4) has been revealed to be involved in various cancers. However, the clinical significance of miR-135b-5p and that of its potential target SFRP4 in PDAC remain to be elucidated. Here, we found that miR-135b-5p was markedly upregulated in pancreatic cancer tissue compared with corresponding adjacent normal tissue, whereas SFRP4 was significantly downregulated. The expression of miR-135b-5p was negatively correlated with the expression of SFRP4. PDAC patients with regional lymph node metastases, vascular invasion, tumor microthrombus and higher PET-CT SUVmax values had significantly higher expression of miR-135b-5p. Immunoblotting revealed that regional lymph node metastases were correlated with expressive states of SFRP4. Negative SFRP4 expression was significantly associated with old age, larger tumor size, regional lymph node metastasis and poor differentiation. Survival analyses demonstrated that miR-135b-5p and SFRP4 could predict outcomes and that miR-135b-5p was an independent predictor. In vitro, the overexpression of miR-135b-5p promoted the migration and proliferation of PANC-1 and MiaPaCa-2 cells, while immunoblotting demonstrated the downregulation of SFRP4 and the upregulation of beta-catenin. Inhibition of miR-135b-5p suppressed migration, induced apoptosis of PANC-1 and AsPC-1 cells, and reduced the expression of beta-catenin. A luciferase reporter assay confirmed that miR-135b-5p repressed the expression of SFRP4 via the direct targeting of its 3’-untranslated regions. In conclusion, the overexpression of miR-135b-5p and the downregulation of SFRP4 were associated with unfavorable clinical characteristics and poor prognosis, and SFRP4 was shown to be a direct downstream target of miR-135b-5p. Thus, the mechanism that underlies the miR-135b-5p-SFRP4-Wnt/beta-catenin axis represents a potential target for PDAC diagnosis and therapy.

MicroRNAs as outcome predictors in patients with metastatic colorectal cancer treated with bevacizumab in combination with FOLFOX

Bevacizumab is a humanized anti-vascular endothelial growth factor monoclonal antibody, used in combination with a oxaliplatin-based chemotherapy in the treatment of metastatic colorectal cancer (mCRC). The aim of the present study was to identify microRNA (miRNA)-based predictive biomarkers of therapy response in order to avoid unnecessary and costly therapy to non-responding patients. High-throughput miRNA microarray profiling (Affymetrix miRNA array) was performed on a discovery cohort of patients with mCRC. The discovery cohort was (n=20) divided into either responding (n=10) or non-responding (n=10) groups of bevacizumab/5-flourouracil, leucovorin, oxaliplatin (FOLFOX) treatment according to Response Evaluation Criteria in Solid Tumors criteria. Validation of candidate miRNAs was performed on an independent cohort of 41 patients with mCRC using quantitative reverse transcription polymerase chain reaction. Normalized data were subjected to receiver operating characteristic and Kaplan-Meier analyses. In total, 67 miRNAs were identified to be differentially expressed when miRNA expression was compared between responding and non-responding patients to bevacizumab/FOLFOX treatment (P<0.05). A total of 7 miRNAs were chosen for independent validation, which confirmed significantly higher expression of miR-92b-3p, miR-3156-5p, miR-10a-5p and miR-125a-5p (P<0.005) in tumor tissue of responding patients compared with non-reponding patients. Using the combination of miRNAs, the present study identified responders to the therapy with sensitivity 82% and specificity 64% (area under the curve = 0.8015). In conclusion, 4 predictive miRNAs associated with progression-free survival (PFS) were identified in patients with mCRC treated with bevacizumab/FOLFOX. Following further independent validations, detection of these miRNA may enable identification of patients with mCRC who may potentially benefit from the therapy.

MTUS1, a gene encoding angiotensin-II type 2 (AT2) receptor-interacting proteins, in health and disease, with special emphasis on its role in carcinogenesis

Loss of tumor suppressor activity is a frequent event in the formation and progression of tumors and has been listed as an important hallmark of cancers. Microtubule-Associated Scaffold Protein 1 (MTUS1) is a candidate tumor suppressor gene which is reported to be frequently down-regulated in a variety of human cancers including pancreas, colon, bladder, head-and-neck, ovarian, breast cancers, gastric, lung cancers. It is also reported to be implicated in several types of pathologies such as cardiac hypertrophy, atherosclerosis, and SLE-like lymphoproliferative diseases. Moreover, MTUS1-encoded proteins are shown to be involved in the regulation of vital cellular processes such as proliferation, differentiation, DNA repair, inflammation, vascular remodeling and senescence. However, the current knowledge is very limited about the role of this gene in human cancers as well as other type diseases. Besides, there is no literature report which summarizes and criticizes the importance of MTUS1 in the cellular processes, especially in the processes of carcinogenesis. Accordingly, in this comprehensive review, we tried to shed light on the role of tumor suppressor MTUS1/ATIP in health and disease, putting special emphasis on its role in the development and progression of human cancers as well as associated molecular mechanisms and the reasons behind MTUS1/ATIP deficiency, which have been not well documented previously.

Peripheral leukocyte microRNAs as novel biomarkers for COPD

COPD is a multifactorial disease caused by environmental determinants as well as genetic risk factors. The prevalence and mortality of COPD continue to increase, and underdiagnosis of COPD remains a critical issue. Previous reports investigated promising microRNAs (miRNAs) to reveal the molecular mechanism for the development of COPD; however, diagnostic and therapeutic markers for COPD have not yet been found. For this study, 20 representative COPD patients were separated into four groups based on increasing severity (A, B, C, and D) and compared to six healthy controls. Small RNA profiles of peripheral leukocytes were differentially expressed miRNAs (analyzed via next-generation sequencing) were validated via quantitative reverse transcriptase-polymerase chain reaction. Compared to healthy controls, 19 differentially expressed miRNAs were found in COPD patients. For all COPD groups, miR-3177-3p was downregulated, while 17 miRNAs were upregulated. Furthermore, the results revealed 21 differentially expressed miRNAs, of which miR-183-5p was continually downregulated from A to B to D. Between respective bronchodilator reversibility positive and negative groups of COPD different groups (A, B, C, and D), 10 miRNAs were differentially expressed, while miR-100-5p was upregulated in the negative groups. In conclusion, miR-106b-5p, miR-125a-5p, miR-183-5p, and miR-100-5p are central for the development of COPD. The severity of COPD was attenuated by miR-106b-5p, thus suggesting this miRNA as potential target for disease treatment.

[Specific microRNA expression profiles of lung adenocarcinoma in Xuanwei region and bioinformatic analysis for predicting their target genes and related signaling pathways]

OBJECTIVE

To identify differentially expressed microRNAs (miRNAs) related to lung adenocarcinoma in Xuanwei region and predict their target genes and related signaling pathways based on bioinformatic analysis.

METHODS

High-throughput microarray assay was performed to detect miRNA expression profiles in 34 paired human lung adenocarcinoma and adjacent normal tissues (including 24 cases in Xuanwei region and 10 in other regions). Gene ontology and KEGG pathway analyses were used to predict the target genes and the regulatory signaling pathways.

RESULTS

Thirty-four miRNAs were differentially expressed in lung adenocarcinoma tissues in cases in Xuanwei region as compared with cases in other regions, including 23 upregulated and 11 downregulated miRNAs. The predicted target genes included GF, RTK, SOS, IRS1, BCAP, CYTOKINSR, ECM, ITGB, FAK and Gbeta;Y involving the PI3K/Alt, WNT and MAPK pathways.

CONCLUSION

The specific microRNA expression profiles of lung adenocarcinoma in cases found in Xuanwei region allow for a better understanding of the pathogenesis of lung adenocarcinoma in Xuanwei. The predicted target genes may involve the PI3K/Alt, WNT and MAPK pathways.