Junfei Xu

Knocking down the expression of adenylate cyclase-associated protein 1 inhibits the proliferation and migration of breast cancer cells

Adenylate cyclase-associated protein 1 (CAP1) is a conserved protein that was found to be up-regulated in breast cancer and related to the migration of breast cancer. We verified its roles in breast cancer specimens and cell lines. In our results, 71 of 100 specimens of breast cancer showed high levels of CAP1 by immunohistochemistry. Associated with statistical analysis, we saw that CAP1 was related to the grade of breast cancer. In MDA-MB-231, the expression of CAP1 was the highest and by knocking down the expression of CAP1 in MDA-MB-231, its ability for proliferating and migrating apparently decreased and induced changes in morphology, which were related to the arrangement of F-actin. Therefore, CAP1 might be a potential molecular targeted therapy for surgery and immune treatment.

Downregulation of microRNA-132 by DNA hypermethylation is associated with cell invasion in colorectal cancer

microRNAs (miRNAs) are small, noncoding RNAs that are involved in many biological processes, and aberrant regulation of miRNAs is always associated with cancer progression and development. Abnormal expression of miRNA-132 (miR-132) has been found in some types of cancer, but the effects and potential mechanisms of miR-132 in colorectal cancer (CRC) have not been explored to date. In this study, quantitative real-time polymerase chain reaction was used to investigate the level of miR-132 in CRC tissues and their paired adjacent normal tissues. Bioinformatics analysis indicated that the mechanism underlying the tumor suppressor role of miR-132 in CRC cells may play a role in tumor suppression by targeting paxillin. Furthermore, methylation-specific polymerase chain reaction was performed to evaluate the methylation status of the miR-132 regulatory region. A DNA methyltransferase inhibitor, 5-aza-2′-deoxycytidine, was used to activate the expression of miR-132 in CRC cells in vitro. Downregulation of miR-132 may occur as a result of hypermethylation and implies a poor prognosis in CRC; therefore, triggering miR-132 reexpression by using DNA methyltransferase inhibitors may be a potential molecular therapeutic target for CRC.

Properties and Clinical Relevance of Speckle-Type POZ Protein in Human Colorectal Cancer

BackgroundThe aims of this study are to evaluate the effect of Speckle-type POZ protein (SPOP) in colorectal cancer (CRC) patients and explore its significance in the prognosis.MethodsWe used immunohistochemistry to detect the expression of SPOP in CRC. Moreover, this result was further confirmed at the protein and messenger RNA (mRNA) level in paired CRC specimens and matched adjacent noncancerous colon tissues by Western blotting and real-time quantitative PCR (qRT-PCR), respectively. Furthermore, we evaluate the effects of SPOP on CRC cell proliferation and migration in vitro. The Kaplan–Meier method and log-rank test were employed to compare the overall survival between SPOP low expression group and SPOP high expression group. Correlation of survival with clinicopathologic parameters, including SPOP level, was investigated with multivariate analyses.ResultsWe confirmed frequent SPOP downregulation in both mRNA (P = 0.0286) and protein (P = 0.004) levels in CRC tissues as compared to matched adjacent nontumorous tissues. Besides, the downregulated SPOP expression in CRC tissues was significantly correlated to poor differentiation (P = 0.013), distant metastasis (P = 0.003), gross type (P < 0.001), and high TNM stage (P = 0.002). Kaplan–Meier survival analysis showed that low SPOP expression exhibited a significant correlation with poor prognosis for CRC patients. Overexpression of SPOP in CRC cell lines significantly suppressed cell proliferation, migration, and clone formation. In contrast, SPOP knockdown dramatically promoted cell proliferation, migration, and clone formation in vitro. In addition, overexpression of SPOP increased E-cadherin and suppressed vimentin in HCT116 cells and silencing of SPOP reversed all these biomarkers. Furthermore, SPOP significantly downregulated MMP2 and MMP7 protein levels in HCT116 cell lines.ConclusionOur results suggest that SPOP plays a pivotal role in colorectal cancer (CRC) through mesenchymal–epithelial transition and MMPs, and it may be a potential therapeutic target in colorectal cancer.

Abnormal expression of calcyphosine is associated with poor prognosis and cell biology function in colorectal cancer

The aim of this study was to investigate the calcyphosine (CAPS) expression in human colorectal cancer (CRC) and to explore its clinical and prognostic significances. CAPS expression was measured by Western blot, real-time polymerase chain reaction analysis, and immunohistochemistry. The relationships between the CAPS expression levels and the clinicopathological factors were investigated. The Kaplan–Meier method and log-rank test were used to investigate the overall survival of the patients. Moreover, the effects of CAPS on biological roles of CRC cells were also evaluated by MTT assay, colony formation assay, and transwell assay. CAPS was significantly overexpressed in cancerous tissue and CRC cell lines compared with adjacent nontumor tissue and a normal human intestinal epithelial cell line. Overexpression of CAPS was significantly associated with histological grade (P=0.004), invasive depth (P<0.001), lymph node metastasis (P=0.003), tumor node metastasis stage (P=0.017), and distant metastasis (P=0.042). Furthermore, silencing of CAPS expression in CRC cells inhibited their proliferation, colony formation, migration, and invasion. Kaplan–Meier survival analysis showed that high CAPS expression might demonstrate poor prognosis in CRC patients. Cox regression analysis revealed that CAPS expression was an independent prognostic factor of CRC. Our data suggested that the upregulation of CAPS might play a role in the carcinogenesis and progression of CRC. CAPS could be used as a potential diagnostic factor and be an independent good prognostic indicator for CRC patients.

miRNA-543 promotes cell migration and invasion by targeting SPOP in gastric cancer

Background/purpose Given the emerging role of microRNA (miRNA) in cancer progression, we investigated the role and mechanism of miRNA-543 (miR-543) in gastric cancer (GC). Materials and methods Real-time quantitative polymerase chain reaction was conducted to quantify the expression of miR-543. Luciferase reporter assay was used to confirm the association between speckle-type POZ protein (SPOP) and 3′-UTR. Moreover, the role of miR-543 and SPOP in GC was detected using transwell assays. In addition, we investigated the function of miR-543 in the epithelial–mesenchymal transition (EMT) progression. Results miR-543 was upregulated in GC. We identified SPOP as a direct target of miR-543, revealing its expression to be inversely correlated with miR-543 expression in GC tissues. Moreover, restoration of SPOP could inhibit miR-543-induced GC cell migration and invasion, whereas downregulation of miR-543 inhibited cell migration and invasion, which was partly abrogated by SPOP knockdown. Furthermore, our data also showed that miR-543 induced EMT of GC cells. Conclusion Our results demonstrated that miR-543 functions as a crucial oncogenic miRNA in GC. It exerts strong tumor-promoting effects through targeting SPOP in GC cell migration and invasion.

MicroRNA‑103 regulates tumorigenesis in colorectal cancer by targeting ZO‑1

Given the emerging role of microRNAs (miRs) in cancer progression, the present study investigated the role and underlying mechanism of miR-103 in colorectal cancer (CRC). Reverse transcription-quantitative polymerase chain reaction was conducted to quantify the expression levels of miR-103 in clinical specimens and cell lines. The role of miR-103 in CRC was examined using MTT, colony formation and transwell assays. In addition, a luciferase reporter assay was used to confirm an associated between the 3′ untranslated region of zonula occuldens-1 (ZO-1) and miR-103. The results demonstrated that miR-103 was upregulated in CRC. Overexpression of miR-103 promoted CRC cell proliferation and migration in vitro, whereas downregulation of miR-103 inhibited cell proliferation and migration. ZO-1 was identified as a direct target of miR-103, revealing its expression to be inversely correlated with miR-103 expression in CRC samples. In conclusion, the present study revealed that miR-103 has strong tumor-promoting effects via of targeting ZO-1 in CRC and has potential development of miRNA-based targeted approaches for the treatment of CRC.