CMTM3 inhibits cell growth and migration and predicts favorable survival in oral squamous cell carcinoma

CMTM Family and Gastrointestinal Tract Cancers: A Comprehensive Review

Gastrointestinal tract cancers are a highly heterogeneous group of malignant diseases, contributing significantly to the burden of death worldwide. Chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing family (CMTMs) plays important roles in cancer development and progression. Since the first member was cloned, there have been abundant studies on the relationships between the CMTM family and human cancers. It has been reported that the CMTM family has a large potential prognostic value for multiple cancers. Meanwhile, upregulated or downregulated expression of the family members was related to advanced tumor stage, metastasis, and overall survival. Studies have also reported that these proteins play critical roles in antitumor immunity. We performed a systematic review to sum up the latest advances of CMTM family' roles in gastrointestinal tract cancers, with a primary focus on hepatocellular carcinoma and gastric carcinoma.

CMTM3 suppresses chordoma progress through EGFR/STAT3 regulated EMT and TP53 signaling pathway

BACKGROUND

Chordomas are rare, slow-growing and locally aggressive bone sarcomas. At present, chordomas are difficult to manage due to their high recurrence rate, metastasis tendency and poor prognosis. The underlying mechanisms of chordoma tumorigenesis and progression urgently need to be explored to find the effective therapeutic targets. Our previous data demonstrates that EGFR plays important roles in chordoma development and CKLF-like MARVEL transmembrane domain containing (CMTM)3 suppresses gastric cancer metastasis by inhibiting the EGFR/STAT3/EMT signaling pathway. However, the roles and mechanism of CMTM3 in chordomas remain unknown.

METHODS

Primary chordoma tissues and the paired adjacent non-tumor tissues were collected to examine the expression of CMTM3 by western blot. The expression of CMTM3 in chordoma cell lines was tested by Real-time PCR and western blot. CCK-8 and colony forming unit assay were performed to delineate the roles of CMTM3 in cell proliferation. Wound healing and Transwell assays were performed to assess cell migration and invasion abilities. A xenograft model in NSG mice was used to elucidate the function of CMTM3 in vivo. Signaling pathways were analyzed by western blot and IHC. RNA-seq was performed to further explore the mechanism regulated by CMTM3 in chordoma cells.

RESULTS

CMTM3 expression was downregulated in chordoma tissues compared with paired normal tissues. CMTM3 suppressed proliferation, migration and invasion of chordoma cells in vitro and inhibited tumor growth in vivo. CMTM3 accelerated EGFR degradation, suppressed EGFR/STAT3/EMT signaling pathway, upregulated TP53 expression and enriched the TP53 signaling pathway in chordoma cells.

CONCLUSIONS

CMTM3 inhibited tumorigenesis and development of chordomas through activating the TP53 signaling pathway and suppressing the EGFR/STAT3 signaling pathway, which suppressed EMT progression. CMTM3 might be a potential therapeutic target for chordomas.

The enzymatic hydrolysates from deer sinew promote MC3T3-E1 cell proliferation and extracellular matrix synthesis by regulating multiple functional genes

Background

Deer Sinew serves as a medicinal food, and has been used for treating skeletal diseases, especially bone diseases in a long history. Thus, it could become an alternative option for the prevention and therapeutic remedy of bone-related diseases. In our previous study, we established an optimal extraction process of the enzymatic hydrolysates from Chinese Sika deer sinews (DSEH), and we demonstrated that DSEH significantly promoted the proliferation of MC3T3-E1 cells (an osteoblast-like cell line) with a certain dose-effect relationship. However, the precise molecular mechanism of deer sinew in regulating bone strength is still largely unknown. The aim of this study was to explore the underlying molecular mechanism of DSEH on MC3T3-E1 cells proliferation and extracellular matrix synthesis.

Methods

Preparation and quality control were performed as previously described. The effect of DSEH at different administrated concentrations on cell proliferation was measured using both CCK-8 and MTT assays, and the capacity of DSEH on extracellular matrix synthesis was detected by Alizarin red staining and quantification. The gene expression pattern change of MC3T3-E1 cells under the treatment of DSEH was investigated by RNA-seq analysis accompanied with validation methods.

Results

We demonstrated that DSEH promoted MC3T3-E1 cell proliferation and extracellular matrix synthesis by regulating multiple functional genes. DSEH significantly increased the expression levels of genes that promoted cell proliferation such as Gstp1, Timp1, Serpine1, Cyr61, Crlf1, Thbs1, Ctgf, P4ha2, Sod3 and Nqo1. However, DSEH significantly decreased the expression levels of genes that inhibited cell proliferation such as Mt1, Cdc20, Gas1, Nrp2, Cmtm3, Dlk2, Sema3a, Rbm25 and Hspb6. Furthermore, DSEH mildly increased the expression levels of osteoblast gene markers.

Conclusions

Our findings suggest that DSEH facilitate MC3T3-E1 cell proliferation and extracellular matrix synthesis to consolidate bone formation and stability, but prevent MC3T3-E1 cells from oxidative stress-induced damage, apoptosis and further differentiation. These findings deepened the current understanding of DSEH on regulating bone development, and provided theoretical support for the discovery of optional prevention and treatment for bone-related diseases.

Expression and biological function of CMTM3 in gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most common malignant tumors in the digestive system with a poor prognosis. The 5-year survival rate of patients with advanced stage GC is low, and most patients have locally advanced or metastatic disease when initially diagnosed, and have therefore lost the opportunity of surgery. The exact molecular mechanism of GC is still unclear.

AIM

To investigate the expression, biological function, and potential molecular regulatory mechanism of CMTM3 gene in GC by bioinformatics analysis and cellular experiments.

METHODS

The differential expression of CMTM3 gene was analyzed in GEO and TCGA databases, and the relationship between CMTM3 gene expression and the prognosis of GC patients was compared. The expression of CMTM3 gene was compared between normal gastric epithelial cells (GES-1) and several GC cell lines (HGC-27, BGC-823, and MKN45). After transfection of exogenous small interfering RNA (sh-CMTM3-1) into MKN45 cells, cell proliferation and migration were evaluated by MTT assay and scratch test. The differentially expressed microRNA profiles in GC tissues and normal gastric tissues were screened from the GEO database, and the upstream target gene miR-125b-5p of CMCT3 was predicted according to the microRNA online prediction software TargetScan. The expression levels of CMTM3 and miR-125b-5p were detected by qPCR in 15 patients with GC at our hospital. Double luciferase reporter assay was performed to verify the relationship between miR-125b-5p and CMTM3 targeted regulation. The proliferation and migration of MKN45 cells were evaluated by transfection of exogenous miR-125b-5p-mimic.

RESULTS

The expression of CMTM3 mRNA in GC tissues was significantly higher than that in adjacent normal gastric tissues (P < 0.05). The overall survival (OS) and disease free survival (DFS) of GC patients with high expression of CMTM3 gene were lower than those of patients with low expression of CMTM3. Exogenous small interfering RNA (sh-CMTM3-1) significantly down-regulated the expression of CMTM3 gene in MKN45 GC cells (P < 0.05). After sh-CMTM3-1-mediated down-regulation of the expression of CMTM3 gene in MKN45 GC cells, cell migration and proliferation were significantly reduced (P < 0.05). The upstream target gene miR-125b-5p of CMTM3 was screened. The expression level of miR-125b-5p in normal gastric mucosa cell line GES-1 was significantly higher than that in GC cell lines (P < 0.05). The expression level of miR-125b-5p in GC tissues was significantly lower than that in adjacent normal tissues (P < 0.05). The expression level of CMTM3 gene in GC tissues was significantly higher than that in adjacent tissues (P < 0.05). There was a negative correlation between the expression of CMTM3 and miR-125b-5p in GC (r_pearson = -0.58, P < 0.05). In MKN45 cells, miR-125b-5p significantly down-regulated the expression of CMTM3 gene (P < 0.05). Double luciferase reporter assay showed that miR-125b-5p gene can bind the 3'-untranslated region of CMTM3 gene. After transfection of miR-125b-5p-mimic to down-regulate the expression of CMTM3, the proliferation and migration of GC MKN45 cells were significantly decreased (P < 0.05).

CONCLUSION

MiR-125b-5p regulates the expression of CMTM3 gene and affects the proliferation and migration of GC. CMTM3 is expected to become a molecular marker and potential therapeutic target for GC.

CMTM3 overexpression promotes cell apoptosis while DHT promotes cell proliferation in hair follicle stem cells (HFSCs)

In Yangtze River Delta white goat, hypermethylation of CMTM3 leads to a decreased expression level in high quality brush hair. However, the regulation of CMTM3 expression and its function in hair follicle stem cells (HFSCs) remains largely unknown. In this study, we investigated the regulation of CMTM3 expression, function, and molecular mechanism in HFSCs. The re-expression of CMTM3 significantly suppressed the proliferation of HFSCs by inducing G1 cell cycle arrest and promoting apoptosis. Moreover, the downregulation of CMTM3 promoted HFSC proliferation. Treatment with sh_CMTM3 and incubation in a DHT culture medium had the most significant growth-promoting effect. It was hypothesized that transcriptome analysis using RNA sequencing (RNA-seq) in samples would enable the identification of unique protein-coding and non-coding genes that may help uncover the role of CMTM3. Multiple genes and pathways were involved in this process, including 168 common DEGs, such as CXCL8 and E-selectin, which is reportedly involved in multiple regulatory pathways. These results indicated that CMTM3 can function as HFSCs through the induction of a G1 cell cycle arrest and promoted apoptosis by mediating crosstalk between several pathways and transcription factors. Our data is available in the National Center for Biotechnology Information (NCBI) database with the accession number PRJNA657430.

CMTM family proteins 1-8: roles in cancer biological processes and potential clinical value

The CKLF-like MARVEL transmembrane domain containing (CMTM) family of genes comprises CKLF and CMTM1–8 (previously called chemokine-like factor superfamily 1–8, CKLFSF1–8). The CMTM family proteins contain a structurally conserved MAL and related proteins for vesicle trafficking and membrane linking (MARVEL) domain. Dysregulated expression of multiple CMTM family members is a common feature in many human cancer types. CMTM proteins control critical biological processes in cancer development, including growth factor receptor activation and recycling, cell proliferation, apoptosis, metastasis, and immune evasion. Emerging in vivo and in vitro evidence indicates that the mechanisms of action of most CMTM proteins are complex and multifactorial. This review highlights new findings regarding the roles of CMTM1–8 in cancer, particularly in tumor growth, metastasis, and immune evasion. Additionally, the potential clinical value of CMTMs as novel drug targets or biomarkers is discussed.

Research Advances in CKLF-like MARVEL Transmembrane Domain-containing Family in Non-small Cell Lung Cancer

CKLF-like MARVEL transmembrane domain-containing member (CMTM) is a new gene family first cloned and reported in 2001. The CMTM family consists of nine members including CKLF and CMTM1-CMTM8, which are located on different chromosomes. Besides exhibiting extensive chemotactic activity, the CMTM family plays an important role in the hematopoiesis system, the immune system, the cardiovascular system and the male reproductive system. Recent in-depth research has also revealed that CMTM is closely associated with the genesis, development and metastasis of tumors, displaying opposing activities in diverse human tumors. In this review, we discuss the structural and functional characteristics of the CMTM family and summarize latest research findings of the relationship between several CMTM members and non-small cell lung cancer.

CMTM4 inhibits cell proliferation and migration via AKT, ERK1/2, and STAT3 pathway in colorectal cancer

CMTM4 (CKLF-like MARVEL transmembrane domain containing 4), a potential tumor suppressor gene, is involved in several types of malignancies. It has been reported to be downregulated and exhibit anti-tumorigenic activities by regulating cell growth and cell cycle in clear cell renal cell carcinoma. It has also been identified as a tumor suppressor in hepatocellular carcinoma (HCC), and its negative expression is a risk factor for poor prognosis of HCC patients. In the present study, an integrated bioinformatics analysis based on The Cancer Genome Atlas (TCGA) database showed that CMTM4 was frequently reduced in colorectal cancer (CRC) and high expression of CMTM4 was associated with increased overall survival rates. Based on these findings, we adopted gain-of-function and lost-of-function strategies using SW480 and HT29 CRC cell lines which have relatively low and high endogenous CMTM4 levels, respectively. We observed impeded cell proliferation and migration upon overexpression of CMTM4 in SW480 cells, and the opposite effects were observed upon knockdown of CMTM4 in HT-29 cells. Cell signaling pathways essential for CRC progression were then examined, and the phosphorylation levels of AKT, ERK1/2, and STAT3 were found to be decreased by CMTM4 overexpression in SW480 cells and elevated by CMTM4 silencing in HT29 cells. Their inhibitors were used to validate that the three signaling pathways contributed to the inhibitory effects of CMTM4 on CRC cells. Taken together, our results suggest that CMTM4 plays a tumor suppressive role in CRC.

Knockdown of CMTM3 promotes metastasis of gastric cancer via the STAT3/Twist1/EMT signaling pathway

CMTM3 (CKLF-like MARVEL transmembrane domain containing 3) possesses tumor suppressor properties in multiple types of malignancies. Restoration of CMTM3 significantly inhibits the metastasis of gastric cancer, and its expression level is correlated with prognosis. However, the physiological effects and the mechanism of CMTM3 remain unknown. Here, we suppress CMTM3 expression by shRNA to explore its endogenous effects and its mechanism of action in gastric cancer. Stable knockdown of CMTM3 promotes cell migration, invasion and tumor metastasis, increases MMP2 expression and enhances MMP2 activity. CMTM3 inhibits EMT along with the upregulation of E-cadherin and the downregulation of N-cadherin, Vimentin and Twist1. It has no obvious effects on Zeb1 and Snail. CMTM3 suppresses the phosphorylation of STAT3 but not Akt. More importantly, the EMT phenotype and cell migration induced by CMTM3 knockdown can be reversed by the Jak2/STAT3 inhibitor JSI-124 or by siRNA against STAT3 or Twist1. Overall, this study demonstrates that knockdown of CMTM3 promotes the metastasis of gastric cancer through the STAT3/Twist1/EMT pathway.

DNA methylation of CMTM3, SSTR2, and MDFI genes in colorectal cancer

Colorectal cancer (CRC) is increasingly common worldwide, including in China. Therefore, there is an increasing need to detect CRC at an early stage and to discover and evaluate diagnostic and prognostic biomarkers. DNA methylation of genes in CRC is a potential epigenetic biomarker for the early detection of CRC. This study was performed to analyze the methylation frequency of six candidate genes, CMTM3, SSTR2, MDFI, NDRG4, TGFB2, and BCL2L11, in fresh-frozen CRC tissues and adjacent normal colorectal tissues, from 42 patients with CRC. DNA isolation, bisulphite modification, and pyrosequencing were performed. The sensitivity, specificity, and the area under the receiver operator characteristic (ROC) curve (AUC) were evaluated to determine whether these genes showed any associations with tumor grade, stage, or diagnostic features. Among the tested genes, three genes, CMTM3, SSTR2, and MDFI were significantly methylated in CRC tissues when compared with adjacent normal colorectal tissues. The ROC analysis showed that a multigene model, including CMTM3, SSTR2, and MDFI, had a sensitivity of 81% and a specificity of 91% with an AUC value of 0.92. The findings of this study have shown that DNA methylation of the genes, CMTM3, SSTR2, and MDFI should be studied further with a view to determining their potential role as biomarkers for CRC.

Chemokine-like factor-like MARVEL transmembrane domain-containing 3 expression is associated with a favorable prognosis in esophageal squamous cell carcinoma

Decreased expression of human chemokine-like factor-like MARVEL transmembrane domain-containing 3 (CMTM3) has been identified in a number of human tumors and tumor cell lines, including gastric and testicular cancer, and PC3, CAL27 and Tca-83 cell lines. However, the association between CMTM3 expression and the clinicopathological features and prognosis of esophageal squamous cell carcinoma (ESCC) patients remains unclear. The aim of the present study was to investigate the correlation between CMTM3 expression and clinicopathological parameters and prognosis in ESCC. CMTM3 mRNA and protein expression was analyzed in ESCC and paired non-tumor tissues by quantitative real-time polymerase chain reaction, western blotting and immunohistochemical analysis. The Kaplan-Meier method was used to plot survival curves and the Cox proportional hazards regression model was also used for univariate and multivariate survival analysis. The results revealed that CMTM3 mRNA and protein expression levels were lower in 82.5% (30/40) and 75% (30/40) of ESCC tissues, respectively, when compared with matched non-tumor tissues. Statistical analysis demonstrated that CMTM3 expression was significantly correlated with lymph node metastasis (P=0.002) and clinical stage (P<0.001) in ESCC tissues. Furthermore, the survival time of ESCC patients exhibiting low CMTM3 expression was significantly shorter than that of ESCC patients exhibiting high CMTM3 expression (P=0.01). In addition, Kaplan-Meier survival analysis revealed that the overall survival time of patients exhibiting low CMTM3 expression was significantly decreased compared with patients exhibiting high CMTM3 expression (P=0.010). Cox multivariate analysis indicated that CMTM3 protein expression was an independent prognostic predictor for ESCC after resection. This study indicated that CMTM3 expression is significantly decreased in ESCC tissues and CMTM3 protein expression in resected tumors may present an effective prognostic biomarker.

CKLF-Like MARVEL Transmembrane Domain-Containing Member 3 (CMTM3) Inhibits the Proliferation and Tumorigenisis in Hepatocellular Carcinoma Cells

The CKLF-like MARVEL transmembrane domain-containing 3 (CMTM3), a member of the CMTM family, was found in several human tumors and plays an important role in the development and progression of tumors. However, the role of CMTM3 in hepatocellular carcinoma (HCC) remains largely unknown. Thus, in the present study, we explored its expression pattern in human HCC cell lines, as well as its functions in HCC cells. Our results demonstrated that the expression of CMTM3 is lowly expressed in HCC cell lines. In vitro, we found that overexpression of CMTM3 obviously inhibited the proliferation, invasion, and EMT process in HCC cells. Furthermore, overexpression of CMTM3 significantly downregulated the expression levels of phosphorylation of JAK2 and STAT3 in HepG2 cells. In vivo, overexpression of CMTM3 attenuated the tumor growth in Balb/c nude mice. In conclusion, we demonstrated that CMTM3 could play an important role in HCC metastasis by EMT induction via, at least partially, suppressing the JAK2/STAT3 signaling pathway. Therefore, CMTM3 may serve as a potential molecular target in the prevention and/or treatment of HCC invasion and metastasis.