SERPINB1 expression is predictive for sensitivity and outcome of cisplatin-based chemotherapy in melanoma

Role of Biomarkers in the Integrated Management of Melanoma

Melanoma, which is an aggressive skin cancer, is currently the fifth and seventh most common cancer in men and women, respectively. The American Cancer Society reported that approximately 106,110 new cases of melanoma were diagnosed in the United States in 2021, with 7,180 people dying from the disease. This information could facilitate the early detection of possible metastatic lesions and the development of novel therapeutic techniques for melanoma. Additionally, early detection of malignant melanoma remains an objective of melanoma research. Recently, melanoma treatment has substantially improved, given the availability of targeted treatments and immunotherapy. These developments have highlighted the significance of identifying biomarkers for prognosis and predicting therapy response. Biomarkers included tissue protein expression, circulating DNA detection, and genetic alterations in cancer cells. Improved diagnostic and prognostic biomarkers are becoming increasingly relevant in melanoma treatment, with the development of newer and more targeted treatments. Here, the author discusses the aspects of biomarkers in the real-time management of patients with melanoma.

KRT81 Knockdown Inhibits Malignant Progression of Melanoma Through Regulating Interleukin-8

KRT81 is involved in carcinogenesis and progression of many types of human cancers. However, little is known about the role of KRT81 in melanoma. In this study, we identified that KRT81 expression is upregulated in melanoma tissues compared with corresponding adjacent nontumor tissues. Overexpression of KRT81 was also found in human melanoma cell lines. Cell functional studies have shown that KRT81 knockdown could inhibit proliferation, colony formation, migration, invasion, and promote apoptosis of A375 cells. Consistently, in vivo tumorigenesis experiments showed that KRT81 knockdown significantly suppressed the growth of xenograft tumors. Moreover, KRT81 knockdown increased the chemosensitivity of A375 cells to DDP. Mechanical exploration revealed that KRT81 knockdown mediated the downregulation of inflammatory cytokine interleukin-8 (IL-8). In conclusion, these findings indicate that downregulation of KRT81 could inhibit progression of melanoma by regulating IL-8. Therefore, KRT81 represents a potential therapeutic target for melanoma therapy.

Berberine-photodynamic therapy sensitizes melanoma cells to cisplatin-induced apoptosis through ROS-mediated P38 MAPK pathways

The clinical use of cisplatin are limited due to its drug resistance. Thus, it is urgent to find effective combination therapy that sensitizes tumor cells to this drug. The combined chemo-photodynamic therapy could increase anti-tumor efficacy while also reduce the side effects of cisplatin. Berberine is an isoquinoline alkaloid, which has been reported to show high photosensitizing activity. In this study, we have examined the effect of a combination of cisplatin and berberine-PDT in cisplatin-resistant melanoma cells. The cytotoxic effects of berberine-PDT alone or in combination with cisplatin were tested by MTT assays. We then examined the subcellular localization of berberine with confocal fluorescence microscopy. The percentage of apoptotic cells, the mitochondrial membrane potential (Δψm) and reactive oxygen species (ROS) generation assessed using flow cytometry analysis. Western blotting used in this study to determine the expression levels of MAPK signaling pathways and apoptosis-related proteins. Experimental data revealed that the mode of cell death is the caspase-dependent mitochondrial apoptotic pathways. Excessive accumulation of ROS played a key role in this process, which is confirmed by alleviation of cytotoxicity upon pretreatment with NAC. Furthermore, we found that the combined treatment activated MAPK signaling pathway. The inhibition of p38 MAPK by pretreating with SB203580 block the combined treatment-induced apoptotic cell death. In conclusion, berberine-PDT could be used as a chemo-sensitizer by promoting cell death through activation of a ROS/p38/caspase cascade.

Transcriptional characterization of conjunctival melanoma identifies the cellular tumor microenvironment and prognostic gene signatures

This study characterizes the transcriptome and the cellular tumor microenvironment (TME) of conjunctival melanoma (CM) and identifies prognostically relevant biomarkers. 12 formalin-fixed and paraffin-embedded CM were analyzed by MACE RNA sequencing, including six cases each with good or poor clinical outcome, the latter being defined by local recurrence and/or systemic metastases. Eight healthy conjunctival specimens served as controls. The TME of CM, as determined by bioinformatic cell type enrichment analysis, was characterized by the enrichment of melanocytes, pericytes and especially various immune cell types, such as plasmacytoid dendritic cells, natural killer T cells, B cells and mast cells. Differentially expressed genes between CM and control were mainly involved in inhibition of apoptosis, proteolysis and response to growth factors. POU3F3, BIRC5 and 7 were among the top expressed genes associated with inhibition of apoptosis. 20 genes, among them CENPK, INHA, USP33, CASP3, SNORA73B, AAR2, SNRNP48 and GPN1, were identified as prognostically relevant factors reaching high classification accuracy (area under the curve: 1.0). The present study provides new insights into the TME and the transcriptional profile of CM and additionally identifies new prognostic biomarkers. These results add new diagnostic tools and may lead to new options of targeted therapy for CM.

Membrane Transporters and Channels in Melanoma

Recent research has revealed that ion channels and transporters can be important players in tumor development, progression, and therapy resistance in melanoma. For example, members of the ABC family were shown to support cancer stemness-like features in melanoma cells, while several members of the TRP channel family were reported to act as tumor suppressors.Also, many transporter proteins support tumor cell viability and thus suppress apoptosis induction by anticancer therapy. Due to the high number of ion channels and transporters and the resulting high complexity of the field, progress in understanding is often focused on single molecules and is in total rather slow. In this review, we aim at giving an overview about a broad subset of ion transporters, also illustrating some aspects of the field, which have not been addressed in detail in melanoma. In context with the other chapters in this special issue on "Transportome Malfunctions in the Cancer Spectrum," a comparison between melanoma and these tumors will be possible.

Patients with Cholangiocarcinoma Present Specific RNA Profiles in Serum and Urine Extracellular Vesicles Mirroring the Tumor Expression: Novel Liquid Biopsy Biomarkers for Disease Diagnosis

Cholangiocarcinoma (CCA) comprises a group of heterogeneous biliary cancers with dismal prognosis. The etiologies of most CCAs are unknown, but primary sclerosing cholangitis (PSC) is a risk factor. Non-invasive diagnosis of CCA is challenging and accurate biomarkers are lacking. We aimed to characterize the transcriptomic profile of serum and urine extracellular vesicles (EVs) from patients with CCA, PSC, ulcerative colitis (UC), and healthy individuals. Serum and urine EVs were isolated by serial ultracentrifugations and characterized by nanoparticle tracking analysis, transmission electron microscopy, and immunoblotting. EVs transcriptome was determined by Illumina gene expression array [messenger RNAs (mRNA) and non-coding RNAs (ncRNAs)]. Differential RNA profiles were found in serum and urine EVs from patients with CCA compared to control groups (disease and healthy), showing high diagnostic capacity. The comparison of the mRNA profiles of serum or urine EVs from patients with CCA with the transcriptome of tumor tissues from two cohorts of patients, CCA cells in vitro, and CCA cells-derived EVs, identified 105 and 39 commonly-altered transcripts, respectively. Gene ontology analysis indicated that most commonly-altered mRNAs participate in carcinogenic steps. Overall, patients with CCA present specific RNA profiles in EVs mirroring the tumor, and constituting novel promising liquid biopsy biomarkers.

Epigenetic Suppression of SERPINB1 Promotes Inflammation-Mediated Prostate Cancer Progression

Granulocytic myeloid infiltration and resultant enhanced neutrophil elastase (NE) activity is associated with poor outcomes in numerous malignancies. We recently showed that NE expression and activity from infiltrating myeloid cells was high in human prostate cancer xenografts and mouse Pten-null prostate tumors. We further demonstrated that NE directly stimulated human prostate cancer cells to proliferate, migrate, and invade, and inhibition of NE in vivo attenuated xenograft growth. Interestingly, reduced expression of SERPINB1, an endogenous NE inhibitor, also correlates with diminished survival in some cancers. Therefore, we sought to characterize the role of SERPINB1 in prostate cancer. We find that SERPINB1 expression is reduced in human metastatic and locally advanced disease and predicts poor outcome. SERPINB1 is also reduced in Pten-null mouse prostate tumors compared with wild-type prostates, and treatment with sivelestat (SERPINB1 pharmacomimetic) attenuates tumor growth. Knockdown of highly expressed SERPINB1 in nonmalignant prostatic epithelial cells (RWPE-1) increases proliferation, decreases apoptosis, and stimulates expression of epithelial-to-mesenchymal transition markers. In contrast, stable SERPINB1 expression in normally low-expressing prostate cancer cells (C4-2) reduces xenograft growth in vivo. Finally, EZH2-mediated histone (H3K27me3) methylation and DNA methyltransferase-mediated DNA methylation suppress SERPINB1 expression in prostate cancer cells. Analysis of The Cancer Genome Atlas and pyrosequencing demonstrate hypermethylation of the SERPINB1 promoter in prostate cancer compared with normal tissue, and the extent of promoter methylation negatively correlates with SERPINB1 mRNA expression. IMPLICATIONS: Our findings suggest that the balance between SERPINB1 and NE is physiologically important within the prostate and may serve as a biomarker and therapeutic target in prostate cancer.

MiR-30a-5p confers cisplatin resistance by regulating IGF1R expression in melanoma cells

BACKGROUND

Melanoma is notoriously resistant to all current modalities of cancer therapies including chemotherapy. In recent years, microRNAs (miRNAs) have emerged as molecular regulators in the development and progression of melanoma. However, the relationship between microRNA and chemo-resistance of melanoma is little known. In present study, we aimed to investigate the miRNAs related to cisplatin-resistance in melanoma cells.

METHODS

After cisplatin (DDP) resistant melanoma cells (M8/DDP and SK-Mel-19/DDP) were established in-vitro, high-throughput screening of differentially expressed miRNAs between resistant cells and parental cells were performed.

RESULTS

It was found that a cancer-related miRNA, miR-30a-5p, was highly over-expressed in resistant cells. Transfection of miR-30a-5p mimic or inhibitor could alter the sensitivity of melanoma cells to cisplatin. Next, we showed that Insulin Like Growth Factor 1 Receptor (IGF1R) gene turned out to be a direct target of miR-30a-5p. Knockdown of IGF1R in melanoma cells could not only reduce the sensitivity to cisplatin but also lead to cell cycle arrest by regulating phosphorylation of Serine-Threonine Protein Kinase (P-AKT (Ser473)) and Tumor Protein P53 (P53).

CONCLUSION

Taken together, our study demonstrated that miR-30a-5p could influence chemo-resistance by targeting IGF1R gene in melanoma cells, which might provide a potential target for the therapy of chemo-resistant melanoma cells.

Down-regulation of GADD45A enhances chemosensitivity in melanoma

Melanoma is a malignant skin cancer with considerable drug resistance. Increased expression of DNA repair genes have been reported in melanoma, and this contributes to chemotherapy resistance. GADD45A is involved in DNA repair, cell cycle arrest and apoptosis in response to physiologic or environmental stresses. In this study, we investigated the role of GADD45A in chemotherapy response. Firstly, the mRNA expression of profiled DNA repair genes in cisplatin-treated melanoma cells was detected by RT2 profilerTM PCR array. We found the expression of GADD45A upregulated in a dose- and time- dependent manner. In addition, suppression of GADD45A sensitized melanoma cells to cisplatin and enhanced cisplatin-induced DNA damage. Flow cytometry revealed that downregulating GADD45A released cells from cisplatin-induced G2/M arrest and increased apoptosis. By using a MEK inhibitor, GADD45A was shown to be regulated by MAPK-ERK pathway following cisplatin treatment. Thus, the induction of GADD45A might play important roles in chemotherapy response in human melanoma cancer and could serve as a novel molecular target for melanoma therapy.

Prognostic relevance of tumor-infiltrating lymphocytes and immune checkpoints in pediatric medulloblastoma

Pediatric medulloblastomas are the most frequently diagnosed embryonal tumors of the central nervous system. Current therapies cause severe neurological and cognitive side effects including secondary malignancies. Cellular immunotherapy might be key to improve survival and to avoid morbidity. Efficient killing of tumor cells using immunotherapy requires to overcome cancer-associated strategies to evade cytotoxic immune responses. Here, we examined the immune response and immune evasion strategies in pediatric medulloblastomas. Cytotoxic T-cells, infiltrating medulloblastomas with variable activation status, showed no correlation with overall survival of the patients. We found limited numbers of PD1⁺ T-cells and complete absence of PD-L1 on medulloblastomas. Medulloblastomas downregulated immune recognition molecules MHC-I and CD1 d. Intriguingly, expression of granzyme inhibitors SERPINB1 and SERPINB4 was acquired in 23% and 50% of the tumors, respectively. Concluding, pediatric medulloblastomas exploit multiple immune evasion strategies to overcome immune surveillance. Absence of PD-L1 expression in medulloblastoma suggest limited or no added value for immunotherapy with PD1/PD-L1 blockers.

Infiltrating Myeloid Cells Exert Protumorigenic Actions via Neutrophil Elastase

Tissue infiltration and elevated peripheral circulation of granulocytic myeloid-derived cells is associated with poor outcomes in prostate cancer and other malignancies. Although myeloid-derived cells have the ability to suppress T-cell function, little is known about the direct impact of these innate cells on prostate tumor growth. Here, it is reported that granulocytic myeloid-derived suppressor cells (MDSC) are the predominant tumor-infiltrating cells in prostate cancer xenografts established in athymic nude mice. MDSCs significantly increased in number in the peripheral circulation as a function of xenograft growth and were successfully depleted in vivo by Gr-1 antibody treatment. Importantly, MDSC depletion significantly decreased xenograft growth. We hypothesized that granulocytic MDSCs might exert their protumorigenic actions in part through neutrophil elastase (ELANE), a serine protease released upon granulocyte activation. Indeed, it was determined that NE is expressed by infiltrating immune cells and is enzymatically active in prostate cancer xenografts and in prostate tumors of prostate-specific Pten-null mice. Importantly, treatment with sivelestat, a small-molecule inhibitor specific for NE, significantly decreased xenograft growth, recapitulating the phenotype of Gr-1 MDSC depletion. Mechanistically, NE activated MAPK signaling and induced MAPK-dependent transcription of the proliferative gene cFOS in prostate cancer cells. Functionally, NE stimulated proliferation, migration, and invasion of prostate cancer cells in vitro IHC on human prostate cancer clinical biopsies revealed coexpression of NE and infiltrating CD33⁺ MDSCs.Implications: This report suggests that MDSCs and NE are physiologically important mediators of prostate cancer progression and may serve as potential biomarkers and therapeutic targets. Mol Cancer Res; 15(9); 1138-52. ©2017 AACR.