Meiling Bao

miR-134 Functions as a Tumor Suppressor in Cell Proliferation and Epithelial-to-Mesenchymal Transition by Targeting KRAS in Renal Cell Carcinoma Cells

Aberrant microRNAs (miRNAs) are reported to contribute to the pathogenesis of most human malignancies. The miRNA, miR-134, has been found to be downregulated in renal cell carcinoma (RCC), but its function in the disease is unknown. The aims of this study were to detect the expression of miR-134 in human RCC samples and explore its function in RCC cell lines. Real-time qualitative polymerase chain reaction (qPCR) was used to quantify miR-134 in human RCC samples. Assays for cell cycle, viability, migration, and invasion were performed to assess the phenotypic changes in RCC cells. A luciferase reporter assay was carried out to confirm whether KRAS (Kirsten rat sarcoma viral oncogene homolog) is a direct target of miR-134. Western blot was used to identify the potential signaling pathways that had an impact on RCC cell growth and alterations of markers for epithelial-mesenchymal transition (EMT), which affected metastasis by miR-134. miR-134 was found to be downregulated in RCC samples (p<0.05), while overexpression of miR-134 suppressed proliferation (p<0.05) by triggering G1/G0 cell cycle arrest (p<0.05). Forced expression of miR-134 could also inhibit migration (p<0.05) and invasion (p<0.05) by blocking EMT in RCC cell lines. KRAS was identified as a target of miR-134, and miR-134 may act as a tumor suppressor through the KRAS-related MAPK/ERK pathway other than PI3K/AKT signaling. Thus, miR-134 may function as a tumor suppressor in cell proliferation and EMT by targeting KRAS in RCC cells.

Expression Pattern of Long Non-Coding RNAs in Renal Cell Carcinoma Revealed by Microarray

Background Recent large-scale transcriptome analyses have found large numbers of transcripts, including that of long non-coding RNAs (lncRNAs), which are aberrant in various diseases, especially cancers. However, it is not clear whether lncRNAs are involved specifically in renal cell carcinoma (RCC). We investigated the expression patterns of lncRNAs in five RCC tumor samples (T) relative to those of matched adjacent non-tumor tissues (N) via microarray. Methods A microarray with 33,045 lncRNA probes and 30,215 mRNA probes was used to identify deregulated lncRNAs in five RCC patients. Furthermore, we confirmed the relative expression levels of AK096725 and ENST00000453068 in 70 paired samples by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Results The lncRNA microarray revealed 27,279 lncRNAs in RCC samples, of which 480 were significantly upregulated (P<0.05; T/N>1.5) and 417 were significantly downregulated (P<0.05; N/T>1.5) compared with the matched non-tumor samples. In addition, 19,995 mRNAs were detected, of which 458 were significantly upregulated (P<0.05; T/N>1.5) and 413 were significantly downregulated (P<0.05; N/T>1.5). The expression level changes of AK096725 (P = 0.043) and ENST00000453068 (P<0.001) in 70 paired samples were in accord with the microarray data. Conclusions The study uncovered expression patterns of lncRNAs in 5 RCC patients, as well as a number of aberrant lncRNAs and mRNAs in tumor samples compared with the non-tumor tissues. The revelation of an association between AK096725 expression and RCC is especially noteworthy. These findings may help to find new biomarkers in RCC.

Laparoscopic Partial Nephrectomy with Precise Segmental Renal Artery Clamping for Clinical T1b Tumors

OBJECTIVE To assess the technique and short-term outcomes of laparoscopic partial nephrectomy (LPN) with precise segmental renal artery clamping for clinical T1b (cT1b) tumors and to analyze the possible factors affecting the glomerular filtration rate (GFR) reduction. MATERIALS AND METHODS This retrospective study investigated the outcomes of 72 patients with cT1b tumors who received LPN from June 2008 to May 2014. Based on three-dimensional dynamic renal vascular models built before surgery, target arteries were precisely clamped and tumors were removed under regional parenchymal ischemia. Perioperative and follow-up outcomes were analyzed. RESULTS All the LPN procedures were effectively performed using the novel technique, without converting to main renal artery clamping or open surgery. The mean operative time was 86 min, with a mean warm ischemic time of 25 min. The median estimated blood loss was 200 mL (range: 80-800). The postoperative mean GFR was 64% of the preoperative baseline, and the total complication rate was 19.4%. In multivariable analyses, the two independent factors affecting postoperative GFR were the RENAL nephrometry score (RNS) and number of intraoperative clamped segmental arteries. The median follow-up was 24 months (range: 6-72). The overall, recurrence-free, and cancer-specific survival rates were 100%, 95.8%, and 100%, respectively. CONCLUSIONS For patients with cT1b tumor, LPN with precise segmental renal artery clamping is safe and feasible for removing tumors and preserving the blood supply and normal renal parenchyma. Short-term oncologic and functional outcomes were satisfactory. Postoperative GFR was related to the preoperative RNS and number of intraoperative clamped segmental arteries.

ALDH1A3 correlates with luminal phenotype in prostate cancer.

Prostate cancer is the most common male malignancies in the United States. The specific characteristics of different disease stages have been deeply investigated. We present our data on ALDH1A3 as a potential therapeutic target for the prostate cancer based on several functional investigations. Also, we used The Cancer Genome Atlas datasets for primary prostate cancer to detect the relevance of ALDH1A3 and prostate cancer luminal phenotype. We found that ALDH1A3 correlated with androgen receptor signaling pathway in primary prostate cancer, which is consistent with its luminal layer localization. Then, from the genetic manipulation assay, we knocked out the ALDH1A3 in PC-3 cells and found significantly reduced proliferation rate as well as the invasion ability. Furthermore, we looked up our single center primary prostate cancer post-operative follow-up data and suggested that the high level ALDH1A3 expression could predict the poor progression-free survival in a 158-patient cohort. We concluded that ALDH1A3, localized in luminal layer in prostate epithelium, is highly expressed in prostate cancer. It played important role in maintaining the proliferation, invasion, and cell cycle. It can also become the potential biomarker in the future to guide the therapeutic manipulations for primary prostate cancer.

Positive expression of NR6A1/CT150 as a predictor of biochemical recurrence-free survival in prostate cancer patients

NR6A1/CT150, as an orphan receptor, is a novel member of the cancer-testis (CT) antigen family. Here, we investigated the expression and function of NR6A1 and its underlying mechanisms in prostate cancer (PCa) patients who underwent radical prostatectomy. A total of 303 cases of prostate cancer after radical prostatectomy were analysed in a tissue microarray (TMA) for NR6A1 immunohistochemistry-based protein expression. Kaplan–Meier/log-rank analysis and Cox regression analysis were used to investigate the relationship between NR6A1 expression and clinicopathological factors in PCa. NR6A1 mRNA expression was examined by reversing transcriptase-polymerase chain reaction (RT-PCR). Knockdown of NR6A1 by small interfering RNA mediated gene silencing and overexpression of NR6A1 through lentivirus were utilized to investigate its potential role in prostate cancer cells. NR6A1 protein expression was 29.7% (90/303) and mRNA expression was 28.1%(9/32) in PCa patients. NR6A1 expression was significantly associated with Gleason score (GS) (P=0.003) and tumor stage (P=0.042). The patients with positive NR6A1 expression have a shorter biochemical recurrence-free survival. NR6A1 predicted biochemical recurrence in univariate (P=0.0159) and multivariate models (P=0.0317). In addition, gene silencing of NR6A1 resulted in G0/G1 phase cell cycle arrest, and decreased metastatic and invasive potential of prostate cancer cells DU145 and PC3. In contrast, overexpression of NR6A1 reduced G0/G1 phase cell cycle arrest, and promoted metastatic and invasive potential of prostate cancer cells 22RV1. And overexpression of NR6A1 significantly promoted tumor growth in vivo. Whats more, down regulation of NR6A1 could reverse epithelial-to-mesenchymal transition (EMT) process in DU145 and PC3 cell lines, and the overexpression could enhance EMT process in 22RV1 cell line. NR6A1 played a prominent role in migration and invasion of PCa cells, and it is indicated that NR6A1 may act as a novel marker for biochemical recurrence after radical prostatectomy.

CD151 promotes cell metastasis via activating TGF-β1/Smad signaling in renal cell carcinoma

Tetraspanin CD151 has been identified as a tumor promoter, which is upregulated in various malignant cell types. However, the function of CD151 and its underlying mechanism in renal cell carcinoma is still unknown. In this study, we detected the expression of CD151 in RCC cells and tissues and explored its regulatory mechanism. We found that CD151 was upregulated in renal cell carcinoma tissues and cells and its expression was significantly associated with tumor stage (p=0.019) and survival (p=0.001) by analyzing tissue microarrays. After silencing of CD151 via lentivirus vector in Caki-1 and Caki-2 cells, reduced ability of migration and invasion were detected with downregulation of CD151. The opposite results were observed in cells with CD151 overexpression. Furthermore, western blotting was performed to investigate the influence of CD151 on epithelial-to-mesenchymal transition, matrix metalloproteinase 9 and TGF-β1/Smad signaling pathway in RCC. Subsequently, upregulating the protein level of transforming growth factor-β1 in cells with silencing of CD151 could rescue the malignant behaviors inhibited, which indicated that CD151 may play its promoting role in RCC partially by stimulating the expression of TGF-β1. Conclusively, CD151 might exhibit a prominent role in migration and invasion of RCC cells via activating TGF-β1/Smad signaling pathway.

MicroRNA‑126 inhibits proliferation and metastasis in prostate cancer via regulation of ADAM9

The aberrant expression of microRNAs (miRs) has been identified to serve a crucial role in tumor progression. The present study aimed to evaluate the role of miR-126 in human prostate cancer (PCa). Firstly, miR-126 expression in prostate cancer tissues and cell lines was analyzed. A luciferase reporter assay and a rescue assay were performed, which identified ADAM metalloproteinase domain 9 (ADAM9) as the target gene of miR-126. Subsequently, Kaplan-Meier and log-rank analyses were used to investigate the association between ADAM9 expression and PCa prognosis. The results revealed that miR-126 expression was significantly downregulated in PCa tissues and cell lines. miR-126 overexpression was demonstrated to reduce PCa cell proliferation and metastasis, and to reverse the epithelial-mesenchymal transition process in vitro. In addition, as the target gene of miR-126, the upregulation of ADAM9 reestablished cell functions, including cell proliferation, migration and invasion. Patients with high ADAM9 expression levels exhibited a shorter biochemical recurrence-free survival time. In summary, miR-126 serves a role in the proliferation and metastasis of PCa cells, indicating that miR-126 and ADAM9 may represent potential biomarkers in the progression of advanced PCa, in addition to therapeutic targets.

Expression of lactate dehydrogenase C correlates with poor prognosis in renal cell carcinoma

Lactate dehydrogenase C is an isoenzyme of lactate dehydrogenase and a member of the cancer–testis antigens family. In this study, we aimed to investigate the expression and functional role of lactate dehydrogenase C and its basic mechanisms in renal cell carcinoma. First, a total of 133 cases of renal cell carcinoma samples were analysed in a tissue microarray, and Kaplan–Meier survival curve analyses were performed to investigate the correlation between lactate dehydrogenase C expression and renal cell carcinoma progression. Lactate dehydrogenase C protein levels and messenger RNA levels were significantly upregulated in renal cell carcinoma tissues, and the patients with positive lactate dehydrogenase C expression had a shorter progression-free survival, indicating the oncogenic role of lactate dehydrogenase C in renal cell carcinoma. In addition, further cytological experiments demonstrated that lactate dehydrogenase C could prompt renal cell carcinoma cells to produce lactate, and increase metastatic and invasive potential of renal cell carcinoma cells. Furthermore, lactate dehydrogenase C could induce the epithelial–mesenchymal transition process and matrix metalloproteinase-9 expression. In summary, these findings showed lactate dehydrogenase C was associated with poor prognosis in renal cell carcinoma and played a pivotal role in the migration and invasion of renal cell carcinoma cells. Lactate dehydrogenase C may act as a novel biomarker for renal cell carcinoma progression and a potential therapeutic target for the treatment of renal cell carcinoma.