PD-1 and CTLA-4 inhibitors in combination vs. alone for the treatment of advanced melanoma: A systematic review and meta-analysis.

BACKGROUND: Metastatic melanoma treatment has drastically changed during the past decade with the advent of immunotherapy. We conducted a meta-analysis, to assess PD-1 and CTLA-4 inhibitors in combination vs. alone for the treatment of advanced melanoma. METHODS: The EMBASE, Medline via PubMed, Scopus, Cochrane Central, and Web of Science databases were searched. The records retrieved were screened for eligibility. Odds ratio (OR) was applied to compare dichotomous variables. All the results were reported with 95% confidence intervals (CI). Mantel-Haenszel method was used to estimate pooled OR and 95% confidence intervals for dichotomous data. RESULTS: We retrieved 3092 citations of which we included 3 randomized controlled trials and 2 retrospective, cohort studies. The pooled OR was 2.144 (95% CI: 1.650-2.786, I2 = 80.38% P = .000) for overall response and 2.117 (95% CI: 1.578-2.841, I2 = 70.17% P = .000) for the complete response (CR). Subgroup analysis in nivolumab category showed that the pooled OR was 1.766 (95% CI: 1.324-2.355, I2 = 0.0% P = .000) for the overall response and was 1.284 (95% CI: 0.889-1.855, I2 = 0.0% P = .182) for the CR and in the ipilimumab category the pooled OR was 5.440 (95% CI: 2.896-10.220, I2 = 70.89% P = .001) for the overall response and was 5.169 (95% CI: 3.163-8.446, I2 = 0.0% P = .000) for the CR. The incidence of any treatment-related adverse events was significantly higher in the combination group than that of the nivolumab monotherapy 4.044 (95% CI: 1.740-9.403, I2 = 91.64% P = .001) or the ipilimumab monotherapy 2.465 (95% CI: 0.839-7.236, I2 = 93.02 % P = .101). CONCLUSION: Combination therapy with ipilimumab plus nivolumab is a promising strategy in the treatment of patients with advanced melanoma with superior overall and complete responses over either monotherapies.

NEDD4 E3 ubiquitin protein ligase serves an important role in cutaneous melanoma occurrence and development.

The present study aimed to discuss the effects and relative mechanisms of NEDD4 E3 ubiquitin protein ligase (NEDD4) in cutaneous melanoma (CMM) occurrence and development. Clinical cancer and adjacent normal tissues samples were collected to analyze pathological changes and protein expression of NEDD4. Moreover, small interfering (si)RNA was used to knockdown NEDD4 expression in SK-MEL-2 and Malme-3M cells. Cellular proliferation, apoptosis, invasiveness and migration were examined using colony formation, flow cytometric, Transwell and wound-healing assays, respectively. In addition, the relative mRNA and protein expression levels of NEDD4, notch receptor 1 (Notch1) and PTEN were evaluated via reverse transcription-quantitative (RT-q) PCR and western blotting. It was found that NEDD4 mRNA and protein expression were significantly upregulated (both P<0.01). Following NEDD4-knockdown, colony number was significantly decreased, while the apoptotic rate was significantly increased, the invasive cell number was significantly inhibited and the wound-healing capacity was significantly decreased. Following si-NEDD4 transfection, RT-qPCR and western blotting revealed that NEDD4 and Notch1 mRNA and protein expression levels were significantly downregulated, while those of PTEN were significantly upregulated in the SK-MEL-2 and Malme-3M cell lines. Collectively, the current results suggest that NEDD4-knockdown effectively suppressed CMM biological activity by regulating the Notch1/PTEN pathway in vitro.

UCHL3 plays an important role in the occurrence and development of melanoma.

It has been reported that ubiquitin C-terminal hydrolase-L3 (UCHL3) plays an important role in cancer development; however, the role of UCHL3 in melanoma remains unclear. The present study aimed to investigate the role of ubiquitin C-terminal hydrolase-L3 (UCHL3) and determine its underlying molecular mechanisms in melanoma occurrence and development using in vitro studies. Reverse transcription-quantitative PCR analysis was performed to detect UCHL3 mRNA expression. The MTT assay was performed to assess cell proliferation. Cell apoptosis was analyzed via flow cytometry and the TUNEL assay. Cell ultrastructure was observed via transmission electron microscopy. LC3B protein expression was detected via cellular immunofluorescence, while neural precursor cell-expressed developmentally downregulated protein 8 (NEDD8) and LC3 protein expression levels, and NEDD8 ubiquitination were detected via western blot analysis. The results demonstrated that transfection with small interfering (si)RNA-UCHL3 significantly suppressed cell proliferation, whereas apoptosis was significantly enhanced, as well as autophagy, autophagosome formation and LC3B protein expression. In addition, NEDD8 protein expression and autophagosome numbers significantly decreased, while the LC3II/LC3I ratio significantly increased. NEDD8 knockdown via transfection with si-NEDD8 had similar effects to si-UCHL3, as well as si-UCHL3+ si-NEDD8. Taken together, the results of the present study suggest that UCHL3 knockdown decreases melanoma cell proliferation by increasing cell autophagy through regulating NEDD8 expression and autophagosome numbers.

miR-152-5p suppresses glioma progression and tumorigenesis and potentiates temozolomide sensitivity by targeting FBXL7.

A generally used chemotherapeutic drug for glioma, a frequently diagnosed brain tumour, is temozolomide (TMZ). Our study investigated the activity of FBXL7 and miR-152-5p in glioma. Levels of microRNA-152-5p (miR-152-5p) and the transcript and protein of FBXL7 were assessed by real-time PCR and Western blotting, respectively. The migratory and invasive properties of cells were measured by Transwell migration and invasion assay and their viability were examined using CCK-8 assay. Further, the putative interaction between FBXL7 and miR-152-5p were analysed bioinformatically and by luciferase assay. The activities of FBXL7, TMZ and miR-152-5p were analysed in vivo singly or in combination, on mouse xenografts, in glioma tumorigenesis. The expression of FBXL7 in glioma tissue is significantly up-regulated, which is related to the poor prognosis and the grade of glioma. TMZ-induced cytotoxicity, proliferation, migration and invasion in glioma cells were impeded by the knock-down of FBXL7 or overexpressed miR-152-5p. Furthermore, the expression of miR-152-5p reduced remarkably in glioma cells and it exerted its activity through targeted FBXL7. Overexpression of miR-152-5p and knock-down of FBXL7 in glioma xenograft models enhanced TMZ-mediated anti-tumour effect and impeded tumour growth. Thus, the miR-152-5p suppressed the progression of glioma and associated tumorigenesis, targeted FBXL7 and increased the effect of TMZ-induced cytotoxicity in glioma cells, further enhancing our knowledge of FBXL7 activity in glioma.

Expression of neddylation-related proteins in melanoma cell lines and the effect of neddylation on melanoma proliferation.

Neddylation promotes the process of ubiquitination, which plays a critical role in the degradation of numerous proteins, including cell cycle and apoptosis regulators. In our previous study, an increase in neddylation was identified in melanoma cell lines. In the present study, the upregulation of neddylation was detected in melanoma tissues which confirmed the results of our previous study on melanoma cell lines. To explore the mechanism by which the process of neddylation was increased, the enzymes that regulate the process were investigated. These neddylation-related regulatory enzymes are potential targets for melanoma therapy. Downregulation of UBA3, a subunit of the E1 enzyme, by RNA interference caused cell cycle arrest at G0/G1 in the M14 cell line. In addition, cyclin D expression declined, whereas p27, p21 and bax expression increased. These findings suggest that interfering with the neddylation pathway may decrease the proliferation of melanoma through the modulation of cell cycle regulators and apoptosis promoters.

Inhibition of SATB1 by shRNA suppresses the proliferation of cutaneous malignant melanoma.

Overexpression of special AT-rich sequence binding protein 1 (SATB1), a global genome organizer, as a predictor of poor prognosis in cutaneous malignant melanoma (CMM) attracted great interest in previous research. In this article, upregulated SATB1 was observed in three melanoma cell lines and in eight CMM tissues. After downregulating SATB1 by RNAi, proliferation of A375 was suppressed in vitro and in vivo. In summary, the proliferation of CMM could be related closely to the SATB1 gene. Interference of this gene may be a promising method for CMM therapy.