Overexpression of myosin VI regulates gastric cancer cell progression

The Suppression of the Epithelial to Mesenchymal Transition in Prostate Cancer through the Targeting of MYO6 Using MiR-145-5p

Aberrant expression of miR-145-5p has been observed in prostate cancer where is has been suggested to play a tumor suppressor role. In other cancers, miR-145-5p acts as an inhibitor of epithelial-to-mesenchymal transition (EMT), a key molecular process for tumor progression. However, the interaction between miR-145-5p and EMT remains to be elucidated in prostate cancer. In this paper the link between miR-145-5p and EMT in prostate cancer was investigated using a combination of in silico and in vitro analyses. miR-145-5p expression was significantly lower in prostate cancer cell lines compared to normal prostate cells. Bioinformatic analysis of The Cancer Genome Atlas prostate adenocarcinoma (TCGA PRAD) data showed significant downregulation of miR-145-5p in prostate cancer, correlating with disease progression. Functional enrichment analysis significantly associated miR-145-5p and its target genes with EMT. MYO6, an EMT-associated gene, was identified and validated as a novel target of miR-145-5p in prostate cancer cells. In vitro manipulation of miR-145-5p levels significantly altered cell proliferation, clonogenicity, migration and expression of EMT-associated markers. Additional TCGA PRAD analysis suggested miR-145-5p tumor expression may be useful predictor of disease recurrence. In summary, this is the first study to report that miR-145-5p may inhibit EMT by targeting MYO6 in prostate cancer cells. The findings suggest miR-145-5p could be a useful diagnostic and prognostic biomarker for prostate cancer.

Elevated expression of myosin VI contributes to breast cancer progression via MAPK/ERK signaling pathway

Breast cancer (BC) is one of the most common malignancies occurring in women worldwide, and its incidence is increasing each year. Accumulating evidence indicated that Myosin VI (MYO6) functions as a gene associated with tumor progression in several cancers. However, the potential role of MYO6 and its underlying mechanisms in the development and progression of BC remains unknown. Herein, we examined the expression levels of MYO6 in BC cells and tissues by western blot and immunohistochemistry. Loss- and gain-of-function investigations in vitro were performed to determine the biological functions of MYO6. And in vivo effects of MYO6 on tumorigenesis were investigated in nude mice. Our findings showed that the expression of MYO6 was up-regulated in breast cancer, and its high expression was correlated with poor prognosis. Further investigation exhibited that silencing the expression of MYO6 significantly inhibited cell proliferation, migration and invasion, whereas overexpression of MYO6 enhanced these abilities in vitro. Also, reduced expression of MYO6 significantly retarded the tumor growth in vivo. Mechanistically, Gene Set Enrichment Analysis (GSEA) revealed that MYO6 was involved in mitogen-activated protein kinase (MAPK) pathway. Moreover, we proved that MYO6 enhanced BC proliferation, migration and invasion via increasing the expression of phosphorylated ERK1/2. Taken together, our findings highlight the role of MYO6 in promoting BC cell progression through MAPK/ERK pathway, suggesting it may be a new potential therapeutic and prognostic target for BC patients.

LINC01224 promotes colorectal cancer progression through targeting miR-485-5p/MYO6 axis

Background

Long noncoding RNAs (lncRNAs) are related to colorectal cancer (CRC) development. However, the role and mechanism of lncRNA LINC01224 in CRC development are largely unknown.

Methods

LINC01224, Yin Yang 1 (YY1), microRNA (miR)-485-5p, and myosins of class VI (MYO6) levels were examined using quantitative reverse transcription polymerase chain reaction and western blotting. Functional analyses were processed through CCK-8, colony formation, flow cytometry, transwell, and xenograft analyses. Dual-luciferase reporter, chromatin immunoprecipitation (ChIP), RNA immunoprecipitation, and pull-down assays were conducted to analyze the binding interaction.

Results

LINC01224 abundance was elevated in CRC tissue samples and cell lines. Elevated LINC01224 might indicate the lower 5-year overall survival in 52 CRC patients. LINC01224 was upregulated via the transcription factor YY1. LINC01224 knockdown restrained CRC cell proliferation, migration, and invasion and increased apoptosis. MiR-485-5p was sponged by LINC01224, and miR-485-5p downregulation relieved the influence of LINC01224 interference on CRC progression. MYO6 was targeted via miR-485-5p and regulated via LINC01224/miR-485-5p axis. MiR-485-5p overexpression suppressed CRC cell proliferation, migration, and invasion and facilitated apoptosis. MYO6 upregulation mitigated the role of miR-485-5p. LINC01224 knockdown decreased xenograft tumor growth.

Conclusion

YY1-induced LINC01224 regulates CRC development via modulating miR-485-5p/MYO6 axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02389-x.

MiRNA-145 and Its Direct Downstream Targets in Digestive System Cancers: A Promising Therapeutic Target

MicroRNAs (miRNAs) play a vital role in the onset and development of many diseases, including cancers. Emerging evidence shows that numerous miRNAs have the potential to be used as diagnostic biomarkers for cancers, and miRNA-based therapy may be a promising therapy for the treatment of malignant neoplasm. MicroRNA-145 (miR-145) has been considered to play certain roles in various cellular processes, such as proliferation, differentiation and apoptosis, via modulating the expression of direct target genes. Recent reports show that miR-145 participates in the progression of digestive system cancers, and plays crucial and novel roles in cancer treatment. In this review, we summarize the recent knowledge concerning the function of miR-145 and its direct targets in digestive system cancers. We discuss the potential role of miR-145 as a valuable biomarker for digestive system cancers and how miR-145 regulates these digestive system cancers via different targets to explore the potential strategy of targeting miR-145.

Insights into the Role of microRNAs in Colorectal Cancer (CRC) Metabolism

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers, with a high mortality rate globally. The pathophysiology of CRC is mainly initiated by alteration in gene expression, leading to dysregulation in multiple signalling pathways and cellular processes. Metabolic reprogramming is one of the important cancer hallmarks in CRC, which involves the adaptive changes in tumour cell metabolism to sustain the high energy requirements for rapid cell proliferation. There are several mechanisms in the metabolic reprogramming of cancer cells, such as aerobic glycolysis, oxidative phosphorylation, lactate and fatty acids metabolism. MicroRNAs (miRNAs) are a class of non-coding RNAs that are responsible for post-transcriptional regulation of gene expression. Differential expression of miRNAs has been shown to play an important role in different aspects of tumorigenesis, such as proliferation, apoptosis, and drug resistance, as well as metabolic reprogramming. Increasing evidence also reports that miRNAs could function as potential regulators of metabolic reprogramming in CRC cells. This review provides an insight into the role of different miRNAs in regulating the metabolism of CRC cells as well as to discuss the potential role of miRNAs as biomarkers or therapeutic targets in CRC tumour metabolism.

Long noncoding RNA UCA1 promotes cell growth, migration, and invasion by targeting miR-143-3p in oral squamous cell carcinoma

BACKGROUND

The long noncoding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) is dysregulated in many types of tumors; however, its role in oral squamous cell carcinoma (OSCC) remains unclear. This study aims to determine the effect of lncRNA UCA1 on OSCC.

METHODS

Fifty-six paired OSCC and adjacent nontumorous tissues were collected and the levels of UCA1, miR-143-3p, and MYO6 in the tissues were evaluated by qRT-PCR. In in vitro experiments, cell viability, migration, and invasion were measured by, respectively, performing CCK-8, wound healing, and transwell assays. The target relationships among UCA1, miR-143-3p, and MYO6 were verified by dual-luciferase assay. Western blot and immunohistochemistry were carried out to determine the protein levels. Xenograft mouse model was established to explore the effects of UCA1 in vivo.

RESULTS

Levels of UCA1 and MYO6 were increased significantly in OSCC, while the level of miR-143-3p was decreased compared with the adjacent nontumorous tissues. UCA1 promoted OSCC cell growth, migration, and invasion both in vitro and in vivo, while miR-143-3p reversed the progression. MYO6 was validated as a target for miR-143-3p, and MYO6 overexpression reversed the effects of miR-143-3p mimic on OSCC cells.

CONCLUSION

LncRNA UCA1 contributes to the proliferation and metastasis of OSCC cells by targeting miR-143-3p and upregulating its downstream gene MYO6. UCA1 could serve as a promising novel target therapy for treatment of OSCC.

HNF1A-AS1 Regulates Cell Migration, Invasion and Glycolysis via Modulating miR-124/MYO6 in Colorectal Cancer Cells

Background

Accumulating evidence determined that lncRNAs play multiple roles in cell progression in colorectal cancer (CRC). Long noncoding RNA (lncRNA) hepatocyte nuclear factor 1 homeobox A (HNF1A)-antisense RNA 1 (AS1) has been identified to affect cell growth and disease diagnosis in various cancers, including CRC. However, the underlying regulatory mechanism of HNF1A-AS1 in cell progression and glycolysis has not been fully explored in CRC.

Materials and Methods

The expression of HNF1A-AS1, microRNA-124 (miR-124) and Myosins of class VI (MYO6) was detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The analysis of glucose consumption, lactate production and hexokinase 2 (HK2) protein level was used to assess glycolysis in cells. The protein level of HK2 and MYO6 was measured with Western blot. Cell migration and invasion were evaluated using the transwell assay. The relationship among HNF1A-AS1, miR-124 and MYO6 was determined via luciferase reporter and RNA immunoprecipitation (RIP) assay.

Results

In this study, we found that HNF1A-AS1 was upregulated in CRC tissues and cell lines. Functional experiments determined that reduction of HNF1A-AS1 or promotion of miR-124 inhibited cell migration and invasion as well as glycolysis in CRC cells. What’ more, luciferase reporter assay manifested that miR-124 was a target of HNF1A-AS1 and MYO6 was a target mRNA of miR-124 in CRC cells. Additionally, reverse experiments showed that the effects of si-HNF1A-AS1 on colorectal cancer cells were impaired by anti-miR-124 and the effects of high miR-124 expression on CRC cells were rescued by upregulating MYO6. HNF1A-AS1 regulated MYO6 expression via targeting miR-124 in CRC cells.

Conclusion

In this study, we first found that HNF1A-AS1 regulated cell migration, invasion and glycolysis via modulating miR-124/MYO6 in CRC cells.

The Emerging Role of Cytoskeletal Proteins as Reliable Biomarkers

Cytoskeletal proteins are essential building blocks of cells. More than 100 cytoskeletal and cytoskeleton-associated proteins are known and for some, their function and regulation are understood in great detail. Apart from cell shape and support, they facilitate many processes such as intracellular signaling and transport, and cancer related processes such as proliferation, migration, and invasion. During the last decade, comparative proteomic studies have identified cytoskeletal proteins as in vitro markers for tumor progression and metastasis. Here, these results are summarized and a number of unrelated studies are highlighted, identifying the same cytoskeletal proteins as potential biomarkers. These findings might indicate that the abundance of these potential markers of tumor progression is associated with the biological outcome and are independent of the cancer origin. This correlates well with recently published results from the Cancer Genome Atlas, indicating that cancers show remarkable similarities in their analyzed molecular information, independent of their organ of origin. It is postulated that the quantification of cytoskeletal proteins in healthy tissues, tumors, in adjacent tissues, and in stroma, is a great source of molecular information, which might not only be used to classify tumors, but more importantly to predict patients' outcome or even best treatment choices.

Cryo-EM structures reveal specialization at the myosin VI-actin interface and a mechanism of force sensitivity

Despite extensive scrutiny of the myosin superfamily, the lack of high-resolution structures of actin-bound states has prevented a complete description of its mechanochemical cycle and limited insight into how sequence and structural diversification of the motor domain gives rise to specialized functional properties. Here we present cryo-EM structures of the unique minus-end directed myosin VI motor domain in rigor (4.6 Å) and Mg-ADP (5.5 Å) states bound to F-actin. Comparison to the myosin IIC-F-actin rigor complex reveals an almost complete lack of conservation of residues at the actin-myosin interface despite preservation of the primary sequence regions composing it, suggesting an evolutionary path for motor specialization. Additionally, analysis of the transition from ADP to rigor provides a structural rationale for force sensitivity in this step of the mechanochemical cycle. Finally, we observe reciprocal rearrangements in actin and myosin accompanying the transition between these states, supporting a role for actin structural plasticity during force generation by myosin VI.

PHGDH is an independent prognosis marker and contributes cell proliferation, migration and invasion in human pancreatic cancer

PURPOSE

To investigate the expression, clinical significance, biological function, and the potential mechanism of PHGDH in pancreatic cancer.

METHODS

The expression of PHGDH in human pancreatic cancer tissues and corresponding adjacent normal tissues were analyzed through immunohistochemistry staining. Simultaneously, the association between the PHGDH expression and the clinicopathological parameters and OS and DFS was evaluated. Human pancreatic cancer cell line BxPC-3 and SW1990 were selected to investigate the effect of PHGDH knockdown on cell proliferation, migration, and invasion. In addition, we performed western blot to assess the expression of cyclin B1, and cyclin D1, MMP-2, and MMP-9 protein.

RESULTS

Our results suggested that the expression of PHGDH is increased in pancreatic cancer compared with adjacent normal tissues and the increased expression of PHGDH is associated with tumor size, lymph node metastasis, and TNM state of pancreatic cancer patients. Moreover, the expression of PHGDH is an independent prognostic indicator for pancreatic cancer patients. In addition, we found that knockdown of PHGDH in pancreatic cancer cells inhibits the cell proliferation, migration, and invasion abilities by down-regulating the expression of cyclin B1, and cyclin D1, MMP-2, and MMP-9.

CONCLUSIONS

Our data indicated that the expression of PHGDH is increased in pancreatic cancer and is an independent molecular prognostic factor for pancreatic cancer patients. In addition, PHGDH controls cell proliferation, migration and invasion abilities. Therefore, PHGDH could serve as an important prognostic indicator and therapeutic target for pancreatic cancer.

miR-143 and miR-145 inhibit gastric cancer cell migration and metastasis by suppressing MYO6

Metastasis is a major clinical obstacle responsible for the high mortality and poor prognosis of gastric cancer (GC). MicroRNAs (miRNAs) are critical mediators of metastasis that act by modulating their target genes. In this study, we found that miR-143 and miR-145 act via a common target gene, MYO6, to regulate the epithelial–mesenchymal transition (EMT) and inhibit metastasis. We determined that miR-143 and miR-145 were downregulated in GC, and the ectopic expression of miR-143 and/or miR-145 inhibited GC cell migration and metastasis. Furthermore, MYO6 was identified as a direct common target of miR-143 and miR-145 and was elevated in GC. Silencing of MYO6 resulted in a metastasis-suppressive activity similar to that of miR-143 and miR-145, while restoring MYO6 attenuated the anti-metastatic or anti-EMT effects caused by miR-143 and miR-145. Clinically, an inverse correlation was observed between miR-143/145 levels and MYO6 levels in GC tissues, and either miR-143/145 downregulation or MYO6 upregulation was associated with more malignant phenotypes in patients with GC. In conclusion, miR-143 and miR-145 suppress GC cell migration and metastasis by inhibiting MYO6 expression and the EMT, which provides a novel mechanism and promising therapeutic target for the treatment of GC metastasis.

RBFOX3 Promotes Tumor Growth and Progression via hTERT Signaling and Predicts a Poor Prognosis in Hepatocellular Carcinoma

Activation of the telomere maintenance mechanism is a key hallmark of cancer. Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of telomerase, which is highly expressed in more than 80% of tumors, including hepatocellular carcinoma (HCC). However, the exact mechanisms by which hTERT is up-regulated in HCCs and promotes tumor growth and progression is not fully understood. The aim of this study was to discover the novel molecular targets that modulate hTERT signaling and HCC growth. In this study, we pulled down and identified RBFOX3 (RNA binding protein fox-1 homolog 3) as a novel hTERT promoter-binding protein in HCC cells using biotin-streptavidin-agarose pull-down and proteomics approach, and validated it as a regulatory factor for hTERT signaling and tumor growth in HCCs. Knockdown of RBFOX3 suppressed the promoter activity and expression of hTERT and consequently inhibited the growth and progression of HCC cells in vitro and in vivo. The suppression of HCC growth mediated by RBFOX3 knockdown could be rescued by hTERT overexpression. Conversely, exogenous overexpression of RBFOX3 activated the promoter activity and expression of hTERT and promoted the growth and progression of HCC cells. Moreover, we found that RBFOX3 interacted with AP-2β to regulate the expression of hTERT. Furthermore, we demonstrated that RBFOX3 expression was higher in the tumor tissues of HCC patients compared to the corresponding paracancer tissues, and was positively correlated with hTERT expression. Kaplan-Meier analysis showed that the HCC patients with high levels of RBFOX3 and hTERT had poor prognosis. Collectively, our data indicate that RBFOX3 promotes HCC growth and progression and predicts a poor prognosis by activating the hTERT signaling, and suggest that the RBFOX3/hTERT pathway may be a potential therapeutic target for HCC patients.