Epigenetic reprogramming of Runx3 reinforces CD8 + T-cell function and improves the clinical response to immunotherapy.

BACKGROUND: Checkpoint blockade immunotherapy, represented by PD-1 or PD-L1 antibody treatment, has been of tremendous success in clinical practice. However, the low clinical response rate and lack of biomarkers for prediction of the immune response limit the clinical application of anti-PD-1 immunotherapy. Our recent work showed that a combination of low-dose decitabine and PD-1-ab significantly improved the complete response (CR) rate of cHL patients from 32 to 71%, which indicates that there is a significant correlation between epigenetic regulation and the clinical response to immunotherapy. METHODS: We recruited two groups of Hodgkin lymphoma patients who were treated with anti-PD-1 and DAC+anti-PD-1. CD8+ T cells were isolated from the patients' peripheral blood, DNA methylation was analyzed by EPIC, the expression profile was analyzed by RNA-seq, and multigroup analysis was performed with IPA and GSEA functional annotations. We explored the effect of DAC on the function of CD8+ T cells in the blood, spleen, tumor and lymph nodes using a mouse model. Furthermore, we explored the function of Tils in the tumor microenvironment. Then, we constructed Runx3-knockout mice to confirm the T-cell-specific function of Runx3 in CD8+ T cells and analyzed various subtypes of T cells and cytokines using mass cytometry (CyTOF). RESULTS: Multiomics analysis identified that DNA methylation reprogramming of Runx3 was a crucial mediator of CD8+ T-cell function. Multiomics data showed that reversal of methylation of the Runx3 promoter promoted the infiltration of CD8+ TILs and mitigated the exhaustion of CD8+ T cells. Furthermore, experiments on tissue-specific Runx3-knockout mice showed that Runx3 deficiency reduced CD8+ T infiltration and the differentiation of effector T and memory T cells. Furthermore, Runx3 deficiency significantly decreased CCR3 and CCR5 levels. Immunotherapy experiments in Runx3 conditional knockout mice showed that DAC could not reverse the resistance of anti-PD-1 in the absence of Runx3. Moreover, both our clinical data and data from TISIDB showed that Runx3 could be a potential biomarker for immunotherapy to predict the clinical response rate. CONCLUSION: We demonstrate that the DNA methylation of Runx3 plays a critical role in CD8+ T-cell infiltration and differentiation during decitabine-primed PD-1-ab immunotherapy, which provides a supporting mechanism for the essential role of epiregulation in immunotherapy.

Pathologic complete response to chemoimmunotherapy of an advanced gastric cancer patient with high PD-L1 expression, dMMR, and unique gut microbiota composition: A case report.

Background: Advanced gastric cancer (AGC) is a malignant disease with limited therapeutic options and a poor prognosis. Recently, immune checkpoint inhibitors (ICIs), represented by inhibitors of programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1), have emerged as a potential gastric cancer (GC) therapy. Case presentation: This case study aimed to reveal the tumor response to neoadjuvant chemotherapy combined with camrelizumab in a patient with AGC based on the characteristics of the clinical pathology, genomics variation, and gut microbiome. Samples from a 59-year-old male patient diagnosed with locally advanced unresectable GC (cT4bN2M0, high grade) presenting PD-L1-positive, deficient mismatch repair (dMMR), and highly specific gut microbiota enrichment were subjected to target region sequencing, metagenomic sequencing, and immunohistochemistry staining. The patient received neoadjuvant therapy, including camrelizumab, apatinib, S-1, and abraxane, which eventually promoted dramatic tumor shrinkage without serious adverse effects and allowed subsequent radical gastrectomy and lymphadenectomy. Finally, the patient achieved pathologic complete response (pCR), and the recurrence-free survival time was 19 months at the last follow-up in April 2021. Conclusions: The patient with PD-L1-positive, dMMR, and a highly specific gut microbiota enrichment exhibited a pCR to neoadjuvant chemoimmunotherapy.

VHL and DNA damage repair pathway alterations as potential clinical biomarkers for first-line TKIs in metastatic clear cell renal cell carcinomas.

PURPOSE: Vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) are being used for the first-line treatment of metastatic clear cell renal cell carcinoma (mccRCC). Here, we set out to explore associations between genomic statuses, gene expression clusters and clinical outcomes of mccRCCs upon the application of VEGFR-TKIs. METHODS: A retrospective study of 56 patients with mccRCC who received first-line VEGFR-TKIs and who underwent genomic profiling and whole transcriptome sequencing was conducted. Survival analysis was carried out using log-rank tests and Cox regression analyses, and Kaplan-Meier curves were plotted. Clustering was performed using the K-means method. RESULTS: Among the 56 patients tested, 17 harbored DNA Damage and Repair (DDR) pathway alterations and 35 VHL mutations. The median progression-free survival (PFS) rates for the DDR and VHL alteration groups were 18 and 18 months, respectively, compared with 14 and 10 months for the nonmutant groups. DDR mutations, VHL mutations and co-mutations were identified as prognostic biomarkers of a longer PFS (p = 0.017, 0.04, 0.014). K-means clustering of expressed transcripts revealed three clusters of 40 patients: C_1, C_2 and C_3. The C_1 cluster exhibited the best PFS and objective response rate (ORR) to TKI therapy, with the highest proportion of DDR and VHL mutations. Further analysis of the tumor immune environment revealed that the C_1 cluster was enriched in activated CD8 T cells and effector CD4 T cells, whereas the C_2 cluster was enriched in eosinophils, mast cells and DC cells and, thus, in immunosuppressive cells. CONCLUSIONS: We found that patients with mccRCC harboring DDR and VHL alterations were more likely to benefit from first-line VEGF-TKI systemic therapy than patients with wild-type disease. In addition, we found that a three-cluster prognostic model based on gene expression can predict PFS and ORR, which was well-matched with activated TIL infiltration.

Camrelizumab combined with apatinib and S-1 as second-line treatment for patients with advanced gastric or gastroesophageal junction adenocarcinoma: a phase 2, single-arm, prospective study.

BACKGROUND: The current second-line treatment of advanced gastric or gastroesophageal junction adenocarcinoma remains unsatisfactory. Anti-PD-1 monoclonal antibody combined with anti-angiogenic therapy shows anti-tumor activity and synergistic effect. We aimed to assess the efficacy and safety of the combination therapy of camrelizumab, apatinib, and S-1 in patients with gastric or gastroesophageal junction adenocarcinoma. METHODS: In this open-label, single-arm, phase 2 trial, in each 21-day cycle, eligible patients received 200 mg intravenous camrelizumab in the first day, 500 mg oral apatinib once daily continuously, and specific dose oral S-1 in the first 14 days until the trial was discontinued disease progression, development of intolerable toxicity, or withdrawal of consent. The primary endpoint was objective response rate. The secondary endpoints were disease control rate, progression-free survival and overall survival, and safety. This study was registered at ClinicalTrials.gov, NCT04345783. RESULTS: Between May 2019 and August 2020, we enrolled a total of 24 patients in this trial. At the data cutoff (December 1, 2020), the median follow-up duration was 8.13 months. Seven of 24 (29.2%, 95%CI 14.9-49.2%) patients reached objective response. The median-progression-free survival was 6.5 months (95%CI 6.01-6.99) and the median overall survival was not reached. Grade 3 or 4 adverse events occurred in 6 (25.0%) patients, including elevated transaminase, thrombocytopenia, fatigue, proteinuria, and intestinal obstruction. No serious treatment-related adverse events or treatment-related deaths occurred. CONCLUSIONS: In this trial, the combination of camrelizumab, apatinib, and S-1 showed promising anti-tumor activity and manageable toxicity as a second-line therapy in patients with advanced gastric or gastroesophageal junction adenocarcinoma, regardless of PD-L1 expression. CLINICAL TRIAL REGISTRATION: NCT04345783.

Exploration of the Tumor-Suppressive Immune Microenvironment by Integrated Analysis in EGFR-Mutant Lung Adenocarcinoma.

BACKGROUND: Clinical evidence has shown that few non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations can benefit from immunotherapy. The tumor immune microenvironment (TIME) is a significant factor affecting the efficacy of immunotherapy. However, the TIME transformational process in EGFR-mutation patients is unknown. METHODS: The mRNA expression and mutation data and lung adenocarcinoma (LUAD) clinical data were obtained from The Cancer Genome Atlas (TCGA) database. Profiles describing the immune landscape of patients with EGFR mutations were characterized by differences in tumor mutation burden (TMB), ESTIMATE, CIBERSORT, and microenvironment cell populations-counter (MCP-counter). RESULTS: In total, the TCGA data for 585 patients were analyzed. Among these patients, 98 had EGFR mutations. The TMB was lower in the EGFR group (3.94 mut/Mb) than in the KRAS mutation group (6.09 mut/Mb, P < 0.001) and the entire LUAD (6.58 mut/Mb, P < 0.001). The EGFR group had a lower population of activated immune cells and an even higher score of immunosuppressive cells. A further inter-group comparison showed that differences in the TMB and tumor-infiltrating lymphocytes were only found between patients with oncogenic mutations and unknown mutation. Meanwhile, there were more myeloid dendritic cells (DCs) in EGFR 19del than in L858R-mutation patients and in common mutation patents than in uncommon mutation patients (P < 0.05). Additionally, we established a D score, where D = MCP-counter score for cytotoxic T lymphocytes (CTLs)/MCP-counter score for myeloid DCs. Further analysis revealed that lower D scores indicated immune suppression and were negatively related to several immunotherapy biomarkers. CONCLUSIONS: The TIME of EGFR mutant NSCLC was immunosuppressive. Myeloid DCs gradually increased in EGFR 19del, L858R, and uncommon mutations. The potential role of CTLs and DCs in the TIME of patients requires further investigation.

En bloc right hemicolectomy with pancreatoduodenectomy for right-sided colon cancer invading duodenum.

BACKGROUND: En bloc right hemicolectomy with pancreatoduodenectomy (RHCPD) is the optimum treatment to achieve the adequate margin of resection (R0) for locally advanced right-sided colon cancer with duodenal invasion. Information regarding the indications and outcomes of this procedure is limited. METHOD: In this retrospective study, 2269 patients with right colon cancer underwent radical right colectomy between October 2010 and May 2019, in which 19 patients underwent RHCPD for LARCC were identified. The overall survival (OS), disease-free survival (DFS), operative mortality, postsurgical complications, gene mutational analysis, and prognostic factors were evaluated. Survival was estimated using Kaplan-Meir method. RESULTS: Of these 19 patients who underwent LARCC, the OS was 88%, 66%, and 58% at 1, 3, and 5 years. The DFS was 72%, 56%, and 56% at 1, 3, and 5 years. The median operative time was 320 min (range: 222-410 min), and the median operative blood loss was 268 mL (range: 100-600 mL). The OS was significantly better among patients with well-differentiated tumor, N0 stage, and high microsatellite instability (MSI) and in patients who received adjuvant chemotherapy. The major postoperative complications occurred in 8 patients (42%), with pancreatic fistula (PF) being the most common. On the basis of the univariate analysis, poorly differentiated tumor, regional lymph node dissemination, MSI status, and no perioperative chemotherapy were the significant predictors of poor survival (P < 0.05). CONCLUSIONS: This study suggests that RHCPD is feasible and can achieve complete tumor clearance with favorable outcome, particularly in patients with lymph node-negative status.

ATR and BRCA2 Simultaneous Mutation in a ccRCC With Sarcomatoid Differentiation and Extensive Metastases: A Case Report.

The genomic landscape and driver-gene mutations differ significantly among diverse histological subtypes of clear cell renal cell carcinoma (ccRCC) due to the intratumoral heterogeneity. Frequent mutations in canonical DNA damage response genes, such as BRCA1/2 or ATR serine/threonine kinase (ATR) haven't been reported even in large-scale genomic profiling of ccRCC researches. Herein, we reported a rare ccRCC harboring ATR and BRCA2 simultaneous mutation with complicated morphologies and extensive metastases. Our case indicates that the deleterious alteration of DNA damage response genes, increasing CD8+ TILs, high PD1/PD-L1 expression and high TMB might contribute to this patient's tumor metastasis and aggressive biological behavior.

Contributions of the National Institute of Parasitic Diseases to the control of visceral leishmaniasis in China.

Visceral leishmaniasis (VL) caused by Leishmania spp. is an important vector-borne disease prevalent in China. VL was rampant in the vast area of China north of the Yangtze River before the founding of the People's Republic of China in 1949. As a result of strenuous interventions, the disease was basically eliminated in most of the former epidemic areas in 1958-60. At present, only sporadic cases occur in the western regions of China. In the process, National Institute of Parasitic Diseases at China CDC and the Chinese Center for Tropical Diseases Research (NIPD-CTDR) have achieved great impact in controlling the diseases as well as in research on Leishmania spp. This review summarized the contribution of experts from NIPD-CTDR to the control and elimination of VL in various aspects, such as understanding the epidemiological features of VL, confirmation of VL vectors and their distribution, development of control tools including diagnostics and insecticides, monitoring and evaluation supported by information management, technical supports to the control programmes, as well as analysis of the challenges faced. At the same time, it puts forward constructive suggestions for the ultimate interruption of VL transmission in China.

Field evaluation of an immunochromatographic test for diagnosis of cystic and alveolar echinococcosis.

BACKGROUND: The larval stages of the tapeworms Echinocoocus granulosus and Echinococcus multilocularis are the causative agents of human cystic echinococcosis (CE) and human alveolar echinococcosis (AE), respectively. Both CE and AE are chronic diseases characterised by long asymptomatic periods of many years. However, early diagnosis of the disease is important if treatment and management of echinococcosis patients are to be successful. METHODS: A previously developed rapid diagnostic test (RDT) for the differential detection of CE and AE was evaluated under field conditions with finger prick blood samples taken from 1502 people living in the Ganzi Tibetan Autonomous Prefecture, China, a region with a high prevalence for both forms of human echinococcosis. The results were compared with simultaneously obtained abdominal ultrasonographic scans of the individuals. RESULTS: Using the ultrasonography as the gold standard, sensitivity and specificity, and the diagnostic accuracy of the RDT were determined to be greater than 94% for both CE and AE. For CE cases, high detection rates (95.6-98.8%) were found with patients having active cysts while lower detection rates (40.0-68.8%) were obtained with patients having transient or inactive cysts. In contrast, detection rates in AE patients were independent of the lesion type. The positive likelihood ratio of the RDT for CE and AE was greater than 20 and thus fairly high, indicating that a patient with a positive test result has a high probability of having echinococcosis. CONCLUSIONS: The results suggest that our previously developed RDT is suitable as a screening tool for the early detection of human echinococcosis in endemic areas.

Transcriptomic and epigenetic analysis of breast cancer stem cells.

AIM: Cancer stem cells (CSCs) drive triple-negative breast cancer recurrence via their properties of self-renewal, invasiveness and radio/chemotherapy resistance. This study examined how CSCs might sustain these properties. MATERIALS & METHODS: Transcriptomes, DNA methylomes and histone modifications were compared between CSCs and non CSCs. RESULTS: Transcriptome analysis revealed several pathways that were activated in CSCs, whereas cell cycle regulation pathways were inhibited. Cell development and signaling genes were differentially methylated, with histone methylation analysis suggesting distinct H3K4me2 and H3K27me3 enrichment profiles. An integrated analysis revealed several tumor suppressor genes downregulated in CSCs. CONCLUSION: Differential activation of various signaling pathways and genes contributes to the tumor-promoting properties of CSCs. Therapeutic targets identified in the analysis may contribute to improving treatment options for patients.

Maternal trans-general analysis of the human mitochondrial DNA pattern.

There is an intimate connection between mitochondrial DNA (mtDNA) methylation and some diseases, such as cancer. MtDNA is almost strictly maternally inherited. However, whether the aberrant mtDNA methylation involved in breast cancer progression and whether mtDNA methylation can be transmitted through maternal line are poorly understood. Here we applied bisulfite sequencing to global mitochondrial DNA and whole genomic DNA methylation array from fifteen members of five three-female-generation families with one breast cancer patient in each family. We found that mtDNA methylation was maternally inherited in D-loop region and eight aberrant mtDNA methylation sites were correlated with breast cancer. Furthermore, conjoint analysis showed that mtDNA methylation sites could be potential biomarkers combined with nuclear DNA methylation sites for breast cancer risk prediction.

Application of liquid biopsy in precision medicine: opportunities and challenges.

Precision medicine for cancer patients aims to adopt the most suitable treatment options during diagnosis and treatment of individuals. Detecting circulating tumor cell (CTC) or circulating tumor DNA (ctDNA) in plasma or serum could serve as liquid biopsy, which would be useful for numerous diagnostic applications. Liquid biopsies can help clinicians screen and detect cancer early, stratify patients to the most suitable treatment and real-time monitoring of treatment response and resistance mechanisms in the tumor, evaluate the risk for metastatic relapse, and estimate prognosis.We summarized the advantages and disadvantages of tissue and liquid biopsies.We also further compared and analyzed the advantages and limitations of detecting CTCs, ctDNAs, and exosomes. Furthermore, we reviewed the literature related with the application of serum or plasma CTCs, ctDNAs, and exosomes for diagnosis and prognosis of cancer.We also analyzed their opportunities and challenges as future biomarkers. In the future, liquid biopsies could be used to guide cancer treatment. They could also provide the ideal scheme to personalize treatment in precision medicine.

Circulating Tumor DNA as Biomarkers for Cancer Detection.

Detection of circulating tumor DNAs (ctDNAs) in cancer patients is an important component of cancer precision medicine ctDNAs. Compared to the traditional physical and biochemical methods, blood-based ctDNA detection offers a non-invasive and easily accessible way for cancer diagnosis, prognostic determination, and guidance for treatment. While studies on this topic are currently underway, clinical translation of ctDNA detection in various types of cancers has been attracting much attention, due to the great potential of ctDNA as blood-based biomarkers for early diagnosis and treatment of cancers. ctDNAs are detected and tracked primarily based on tumor-related genetic and epigenetic alterations. In this article, we reviewed the available studies on ctDNA detection and described the representative methods. We also discussed the current understanding of ctDNAs in cancer patients and their availability as potential biomarkers for clinical purposes. Considering the progress made and challenges involved in accurate detection of specific cell-free nucleic acids, ctDNAs hold promise to serve as biomarkers for cancer patients, and further validation is needed prior to their broad clinical use.

DNA methylation signatures in circulating cell-free DNA as biomarkers for the early detection of cancer.

Detecting cell-free DNA (cfDNA) or circulating tumor DNA (ctDNA) in plasma or serum could serve as a "liquid biopsy", which would be useful for numerous diagnostic applications. cfDNA methylation detection is one of the most promising approaches for cancer risk assessment. Here, we reviewed the literature related to the use of serum or plasma circulating cell-free DNA for cancer diagnosis in the early stage and their power as future biomarkers.

MAGE-A1 promotes melanoma proliferation and migration through C-JUN activation.

MAGE-A1 belongs to the chromosome X-clustered genes of cancer-testis antigen family and is normally expressed in the human germ line but is also overexpressed in various tumors. Previous studies of MAGE-A1 in melanoma mainly focused on methylation changes or its role in immunotherapy, however, its biological functions in melanoma have remained unknown. In order to determine the role of MAGE-A1 in melanoma growth and metastasis, we manipulated melanoma cell lines with overexpression and knockdown of MAGE-A1. Integration of cell proliferation assays, transwell migration and invasion assays, and RNA-Seq analysis revealed that up-regulation of MAGE-A1 dramatically promoted proliferation, migration, and invasion of human melanoma cell lines in vitro, while down-regulation of MAGE-A1 inhibited those characteristics associated with tumor cells. Furthermore, transcriptome sequencing revealed that MAGE-A1 exerts its tumor promoting activity by activating p-C-JUN directly or through ERK-MAPK signaling pathways. Based on our findings, we propose that MAGE-A1 may be a potential therapeutic target for melanoma patients.

[Molecular networks and mechanisms of epithelial-mesenchymal transition regulated by miRNAs in the malignant melanoma cell line].

Melanoma is a malignant cutaneous cancer of high metastasis and lethal rates. Epithelial-mesenchymal transition (EMT) plays an important role in the embryonic developmental process that is often activated during tumorigenesis and metastasis. In this study, we integrated of mRNA and miRNA transcriptome sequencing data of melanocyte and melanoma cell lines to identify genes involved in the process of tumor EMT in the first place, and uncovered 11 miRNAs including miR-130a-3p, miR-130b-3p, miR-125a-5p, miR-30a-3p, miR-195-5p, miR-345-5p, miR-509-3-5p, miR-374a-5p, miR-509-5p, miR-148a-3p and miR-330-3p, negatively related with EMT genes using the Mirsystem software. Bioinformatics analysis with target genes of these miRNAs revealed two networks closely related with cellular development and cell-to-cell interactions, as well as multiple signaling pathways participating in EMT. Validation of the 11 miRNAs with molecular biology experiments demonstrated that four miRNAs regulated oncogenes in melanomas, including miR-195-5p, miR-130a-3p, miR-509-5p, and miR-509-3-5p. Our study integrates two kinds of omics data to screen for EMT-related miRNAs, providing a new research idea in the precision genomics of cancer research.

Development of an Immunochromatographic Test for Diagnosis of Visceral Leishmaniasis Based on Detection of a Circulating Antigen.

BACKGROUND: Visceral leishmaniasis (VL) is a life-threatening disease caused by protozoan parasites of the Leishmania donovani complex. Early case detection followed by adequate treatment is essential to the control of VL. However, the available diagnostic tests are either invasive and require considerable expertise (parasitological demonstration of the parasite in tissue smears) or unable to distinguish between past and active infection (serological methods). Therefore, we aimed to develop a lateral flow assay in the form of an immunochromatographic test (ICT) device based on the detection of a circulating Leishmania antigen using monoclonal antibodies (mAbs). METHODOLOGY/PRINCIPAL FINDINGS: mAbs were produced by fusion of murine myeloma cells with splenocytes isolated from a mouse immunized with L. donovani soluble crude antigen. Out of 12 cloned hybridoma cell lines, two secreted mAbs recognizing the same leishmanial protein. These mAbs were used to produce an ICT as a sandwich assay for the detection of circulating antigen in serum and blood samples. The ICT was evaluated with 213 serum samples from VL patients living in VL endemic areas in China, and with 156 serum samples from patients with other diseases as well as 78 serum samples from healthy donors. Sensitivity, specificity and diagnostic efficiency of the new ICT was 95.8%, 98.7% and 97.3%, respectively. Compared with a commercially available antibody detecting ICT, our antigen-based ICT performed slightly better. CONCLUSION/SIGNIFICANCE: The newly developed ICT is an easy to use and more accurate diagnostic tool which fulfils the performance and operational characteristics required for VL case detection under field and laboratory conditions. As our ICT detects a circulating antigen, it will also be useful in monitoring treatment success and diagnosing VL in immunocompromised patients.

Deep sequencing analysis of microRNA expression in human melanocyte and melanoma cell lines.

Melanoma is a type of skin cancer that is highly aggressive, and is considered the most deadly of all skin cancers. Currently, there are no effective therapies for melanomas once they undergo metastasis. MicroRNAs (miRNAs) are small, single-stranded, non-coding RNA molecules that can post-transcriptionally regulate gene expression. They have been reported to be associated with the occurrence of many diseases, including human melanoma. However, the mechanisms by which miRNAs exert their effects remain unclear; therefore, a systematic analysis of the miRNAome in human melanoma is necessary. We investigated the miRNAome in human melanocyte and melanoma cell lines using high-throughput RNA sequencing. We identified a group of dysregulated miRNAs by comparing the miRNA expression profiles among the melanoma cell lines. Target genes of these miRNAs encode proteins whose functions are associated with the cell cycle and apoptosis. Gene networks were built to investigate the interactions of genes during melanoma progression. We identified that the key genes that regulate melanoma cell proliferation were regulated by miRNAs. In summary, our investigation of the human melanoma miRNAome using high-throughput sequencing revealed a number of previously unreported miRNAs associated with malignant progression of melanoma. Our findings add to existing knowledge regarding the mechanisms of melanoma development.

Insulin-like growth factor binding protein 5 (IGFBP5) functions as a tumor suppressor in human melanoma cells.

The insulin-like growth factor binding protein 5 (IGFBP5), which is often dysregulated in human cancers, plays a crucial role in carcinogenesis and cancer development. However, the function and underlying mechanism of IGFBP5 in tumor growth and metastasis has been elusive, particularly in malignant human melanoma. Here, we reported that IGFBP5 acts as an important tumor suppressor in melanoma tumorigenicity and metastasis by a series of experiments including transwell assay, xenograft model, in vivo tumor metastasis experiment, and RNA-Seq. Overexpression of IGFBP5 in A375, a typical human melanoma cell line, inhibited cell malignant behaviors significantly, including in vitro proliferation, anchorage-independent growth, migration and invasion, as well as in vivo tumor growth and pulmonary metastasis. In addition, overexpression of IGFBP5 suppressed epithelial-mesenchymal transition (EMT), and decreased the expression of E-cadherin and the key stem cell markers NANOG, SOX2, OCT4, KLF4, and CD133. Furthermore, IGFBP5 exerts its inhibitory activities by reducing the phosphorylation of IGF1R, ERK1/2, and p38-MAPK kinases and abating the expression of HIF1α and its target genes, VEGF and MMP9. All these findings were confirmed by IGFBP5 knockdown in human melanoma cell line A2058. Taken together, these results shed light on the mechanism of IGFBP5 as a potential tumor-suppressor in melanoma progression, indicating that IGFBP5 might be a novel therapeutic target for human melanoma.

Whole transcriptome RNA-seq analysis: tumorigenesis and metastasis of melanoma.

Melanoma is the most malignant cutaneous cancer and causes over 9000 deaths annually. Because fatality rates from malignant melanoma (MM) increase dramatically upon metastasis, we investigated tumorigenesis and metastasis of MM in transcriptome analyses of three distinct cell lines that correspond with the stages of MM pathogenesis: the normal stage (HEMn-LP), the onset of MM (A375), and the metastasis stage (A2058). Using next-generation sequencing (NGS) technology, we detected asymmetrical expression of genes among the three cell lines, notably on chromosomes 9, 11, 12, and 14, suggesting their involvement in tumorigenesis and metastasis of MM. These genes were clustered into 41 categories based on their expression patterns, and their biological functions were analyzed using Ingenuity Pathway Analysis. In the top cancer-associated category, HIF1A, IL8, TERT, ONECUT1, and FOXA1 directly interacted with either transcription factors or cytokines that are known to be involved in the tumorigenesis or metastasis of other malignant tumors. The present data suggest that cytokine regulatory pathways in macrophages predominate over other pathways during the pathogenesis of MM. This study provides new targets for the downstream mechanistic studies of the tumorigenesis and metastasis of MM and demonstrates a new strategy for studies of the progression of other malignant cancers.