Identification of key candidate genes involved in melanoma metastasis

Antitumor Effect of Poplar Propolis on Human Cutaneous Squamous Cell Carcinoma A431 Cells

Propolis is a gelatinous substance processed by western worker bees from the resin of plant buds and mixed with the secretions of the maxillary glands and beeswax. Propolis has extensive biological activities and antitumor effects. There have been few reports about the antitumor effect of propolis against human cutaneous squamous cell carcinoma (CSCC) A431 cells and its potential mechanism. CCK-8 assays, label-free proteomics, RT-PCR, and a xenograft tumor model were employed to explore this possibility. The results showed that the inhibition rate of A431 cell proliferation by the ethanol extract of propolis (EEP) was dose-dependent, with an IC50 of 39.17 μg/mL. There were 193 differentially expressed proteins in the EEP group compared with the control group (p < 0.05), of which 103 proteins (53.37%) were upregulated, and 90 proteins (46.63%) were downregulated. The main three activated and suppressed Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were extracellular matrix (ECM)-receptor interaction, amoebiasis, cell adhesion molecules (CAMs), nonalcoholic fatty liver disease (NAFLD), retrograde endocannabinoid signaling, and Alzheimer's disease. The tumor volume of the 100 mg/kg EEP group was significantly different from that of the control group (p < 0.05). These results provide a theoretical basis for the potential treatment of human CSCC A431 cell tumors using propolis.

Bioinformatic analysis identifies epidermal development genes that contribute to melanoma progression

Several diagnostic and prognostic markers for melanoma have been identified in last few years. However, their actual contribution to melanoma progression have not been investigated in detail. This study was aimed to identify genes, biological processes, and signaling pathways implicated in melanoma progression by applying bioinformatics analysis. We identified nine differentially expressed genes (DEGs) (IL36RN, KRT6A, KRT6B, KRT16, S100A7, SPRR1A, SPRR1B, SPRR2B, and KLK7) that were upregulated in primary melanoma compared with metastatic melanoma in all five datasets analyzed. All these genes except IL36RN, both form a protein-protein interaction network and have cellular functions associated with constitutive processes of keratinocytes. Thus, they were generically termed Epidermal Development and Cornification (EDC) genes. The differential expression of these genes in primary and metastatic melanoma was confirmed in the TCGA-SKCM cohort. High expression of the EDC genes correlated with reduced tumor thickness in primary melanoma and shorter survival in metastatic melanoma. Analysis of DEGs from primary melanoma patients displaying high or low expression of all eight EDC revealed that the upregulated genes are enriched in biological process related to cell migration, extracellular matrix organization, invasion, and Epithelial-Mesenchymal Transition. Further analysis of enriched curated oncogenic genesets together with RPPA data of phosphorylated proteins revealed the activation of MEK, ATF2, and EGFR pathways in tumors displaying high expression of EDC genes. Thus, EDC genes may contribute to melanoma progression by promoting the activation of MEK, ATF2, and EGFR pathways together with biological processes associated with tumor aggressiveness.

circRNA: A New Biomarker and Therapeutic Target for Esophageal Cancer

Circular RNAs (circRNAs) comprise a large class of endogenous non-coding RNA with covalently closed loops and have independent functions as linear transcripts transcribed from identical genes. circRNAs are generated by a “back-splicing” process regulated by regulatory elements in cis and associating proteins in trans. Many studies have shown that circRNAs play important roles in multiple processes, including splicing, transcription, chromatin modification, miRNA sponges, and protein decoys. circRNAs are highly stable because of their closed ring structure, which prevents them from degradation by exonucleases, and are more abundant in terminally differentiated cells, such as brains. Recently, it was demonstrated that numerous circRNAs are differentially expressed in cancer cells, and their dysfunction is involved in tumorigenesis and metastasis. However, the crucial functions of these circRNAs and the dysregulation of circRNAs in cancer are still unknown. In this review, we summarize the recent reports on the biogenesis and biology of circRNAs and then catalog the advances in using circRNAs as biomarkers and therapeutic targets for cancer therapy, particularly esophageal cancer.

Evaluation of cfDNA as an early detection assay for dense tissue breast cancer

A cell-free DNA (cfDNA) assay would be a promising approach to early cancer diagnosis, especially for patients with dense tissues. Consistent cfDNA signatures have been observed for many carcinogens. Recently, investigations of cfDNA as a reliable early detection bioassay have presented a powerful opportunity for detecting dense tissue screening complications early. We performed a prospective study to evaluate the potential of characterizing cfDNA as a central element in the early detection of dense tissue breast cancer (BC). Plasma samples were collected from 32 consenting subjects with dense tissue and positive mammograms, 20 with positive biopsies and 12 with negative biopsies. After screening and before biopsy, cfDNA was extracted, and whole-genome next-generation sequencing (NGS) was performed on all samples. Copy number alteration (CNA) and single nucleotide polymorphism (SNP)/insertion/deletion (Indel) analyses were performed to characterize cfDNA. In the positive-positive subjects (cases), a total of 5 CNAs overlapped with 5 previously reported BC-related oncogenes (KSR2, MAP2K4, MSI2, CANT1 and MSI2). In addition, 1 SNP was detected in KMT2C, a BC oncogene, and 9 others were detected in or near 10 genes (SERAC1, DAGLB, MACF1, NVL, FBXW4, FANK1, KCTD4, CAVIN1; ATP6V0A1 and ZBTB20-AS1) previously associated with non-BC cancers. For the positive–negative subjects (screening), 3 CNAs were detected in BC genes (ACVR2A, CUL3 and PIK3R1), and 5 SNPs were identified in 6 non-BC cancer genes (SNIP1, TBC1D10B, PANK1, PRKCA and RUNX2; SUPT3H). This study presents evidence of the potential of using cfDNA somatic variants as dense tissue BC biomarkers from a noninvasive liquid bioassay for early cancer detection.

Analyzing Prognostic Hub Genes in the Microenvironment of Cutaneous Melanoma by Computer Integrated Bioinformatics

Cutaneous melanoma (CM) is attracting increasing attention due to high mortality. In response to this, we synthetically analyze the CM dataset from the TCGA database and explore microenvironment-related genes that effectively predict patient prognosis. Immune/stromal scores of cases are calculated using the ESTIMATE algorithm and are significantly associated with overall patient survival. Then, differentially expressed genes are identified by comparing the immune score and stromal score, also prognostic genes are subsequently screened. Functional analysis shows that these genes are enriched in different activities of immune system. Moreover, 19 prognosis-related hub genes are extracted from the protein-protein interaction network, of which four unreported genes (IL7R, FLT3, C1QC, and HLA-DRB5) are chosen for validation. A significant negative relationship is found between the expression levels of the 4 genes and pathological stages, notably T grade. Furthermore, the K-M plots and TIMER results show that these genes have favorable value for CM prognosis. In conclusion, these results give a novel insight into CM and identify IL7R, FLT3, C1QC, and HLA-DRB5 as crucial roles for the diagnosis and treatment of CM.

Targeting GPCRs and Their Signaling as a Therapeutic Option in Melanoma

Simple Summary

Sixteen G-protein-coupled receptors (GPCRs) have been involved in melanogenesis or melanomagenesis. Here, we review these GPCRs, their associated signaling, and therapies.

Abstract

G-protein-coupled receptors (GPCRs) serve prominent roles in melanocyte lineage physiology, with an impact at all stages of development, as well as on mature melanocyte functions. GPCR ligands are present in the skin and regulate melanocyte homeostasis, including pigmentation. The role of GPCRs in the regulation of pigmentation and, consequently, protection against external aggression, such as ultraviolet radiation, has long been established. However, evidence of new functions of GPCRs directly in melanomagenesis has been highlighted in recent years. GPCRs are coupled, through their intracellular domains, to heterotrimeric G-proteins, which induce cellular signaling through various pathways. Such signaling modulates numerous essential cellular processes that occur during melanomagenesis, including proliferation and migration. GPCR-associated signaling in melanoma can be activated by the binding of paracrine factors to their receptors or directly by activating mutations. In this review, we present melanoma-associated alterations of GPCRs and their downstream signaling and discuss the various preclinical models used to evaluate new therapeutic approaches against GPCR activity in melanoma. Recent striking advances in our understanding of the structure, function, and regulation of GPCRs will undoubtedly broaden melanoma treatment options in the future.

Circ-LTBP1 is involved in doxorubicin-induced intracellular toxicity in cardiomyocytes via miR-107/ADCY1 signal

Although doxorubicin (DOX) is a broad-spectrum and anthracycline chemotherapeutic agent, cardiotoxicity limits its clinical application. Therefore, it is meant to prevent the clinical side effects of DOX. Human cardiomyocyte-like AC16 cells were treated with DOX to induce intracellular toxicity. AC16 cell viability was determined by Cell Counting Kit 8 and 5-ethynyl-2'-deoxyuridine assays. The tumor necrosis factor-α and interleukin-6 abundances were quantified by matched kits. The apoptosis rate was measured by flow cytometry. Western blot analysis was conducted to measure the protein expression levels in AC16 cells. Oxidative stress was analyzed by measuring superoxide dismutase and malondialdehyde production. The quantitative real-time polymerase chain reaction was conducted to assess the expression levels of circ-latent transforming growth factor-beta binding protein-1 (circ-LTBP1), microRNA-107 (miR-107), and Adenylate cyclase 1 (ADCY1) expression in AC16 cells. The interaction relationship among circ-LTBP1, miR-107, and ADCY1 was verified by dual-luciferase reporter and RNA immunoprecipitation assays. As a result, treatment with DOX induced the proliferation inhibition, inflammation, apoptosis, and oxidative stress in AC16 cells, which were rescued by circ-LTBP1 inhibition or miR-107 upregulation. MiR-107 was confirmed as a target of circ-LTBP1, and inhibition of circ-LTBP1-mediated effects on DOX-stimulated cells were abolished by downregulation of miR-107. Circ-LTBP1 mediated ADCY1 expression by sponging miR-107 in AC16 cells. The upregulation of miR-107 increased cell proliferation and inhibited inflammation, apoptosis, and oxidative stress in DOX-stimulated cells through downregulation of ADCY1. Circ-LTBP1 was found to enhance DOX-induced effects on proliferation inhibition, inflammation, apoptosis, and oxidative stress in AC16 cells through competitively sponging miR-107 and elevating ADCY1.

COL17A1 germline variant p.Ser1029Ala and mucosal malignant melanoma: An autopsy study

Collagen type XVII α1 (COL17A1) encodes a hemidesmosomal protein at the epidermal-dermal junction and its variants are implicated in blistering skin diseases. Recent experiments in rodents revealed that Col17a1 has critical roles in stem cells of epidermal origin and in melanoma carcinogenesis. In the present study, it was investigated whether germline variants in COL17A1 are associated with skin cancer and other cancer types using indexed consecutive autopsy cases from the Japanese Geriatric Single Nucleotide Polymorphism database (n=2,343; mean age, 80 years). The database included 12 patients with skin cancer. A total of 53 COL17A1 missense variants on an exome chip were analyzed. One variant, p.Ser1029Ala (rs118166857), which had a minor allele frequency of 1.0%, exhibited a nominal positive sign of association with skin cancer [Fisher's exact P=0.002, odds ratio (OR)=16.93, 95% CI: 4.44-64.64]. This variant was detected in 2/2 patients with mucosal malignant melanoma (mMM) and 1/3 patients with extramammary Paget's disease, and in none of the patients with non-melanoma cancer, e.g., squamous cell and basal cell carcinoma. Other cancer types were searched in the database and the p.Ser1029Ala variant was indicated to be nominally associated with breast cancer (P=0.006, OR=4.17, 95% CI: 1.72-10.11). In the two mMM cases, targeted exome sequencing of 55 cancer-predisposing genes (including tumor protein 53, BRCA1/2 and mismatch repair genes) detected no apparent pathogenic variants, but revealed variants of unknown significance in axin 2, DNA directed polymerase ζ catalytic subunit and contactin 6. Since COL17A1 provides a niche for melanocyte stem cells, it was hypothesized that the p.Ser1029Ala variant in the COL17A1 ectodomain may affect the microenvironment, e.g., the cell competition. This is a working hypothesis generated from human autopsy cases and warrants further epidemiological and molecular biological validation.

CRYAB predicts clinical prognosis and is associated with immunocyte infiltration in colorectal cancer

Background

αB-Crystallin (CRYAB) is differentially expressed in various tumors. However, the correlation between CRYAB and immune cell infiltration in colorectal cancer (CRC) remains unclear.

Materials & Methods

Kaplan-Meier survival curves in The Cancer Genome Atlas (TCGA) were used to evaluate the relationship between CRYAB expression and both overall survival and progression-free survival. The relationships between CRYAB expression and infiltrating immune cells and their corresponding gene marker sets were examined using the TIMER database.

Results

The expression of CRYAB was lower in CRC tumor tissues than in normal tissues (P < 0.05). High CRYAB gene expression and high levels of CRYAB gene methylation were correlated with high-grade malignant tumors and more advanced tumor, nodes and metastasis (TNM) cancer stages. In addition, in colorectal cancer, there was a positive correlation between CRYAB expression and immune infiltrating cells including neutrophils, macrophages, CD8 + T cells, and CD4 + T cells, as well as immune-related genes including CD2, CD3D, and CD3E. Methylation sites such as cg13084335, cg15545878, cg13210534, and cg15318568 were positively correlated with low expression of CRYAB.

Conclusion

Because CRYAB likely plays an important role in immune cell infiltration, it may be a potential tumor-suppressor gene in CRC and a potential novel therapeutic target and predictive biomarker for colorectal cancer (CRC).

Genomic and Transcriptomic Underpinnings of Melanoma Genesis, Progression, and Metastasis

Melanoma is a deadly skin cancer with rapidly increasing incidence worldwide. The discovery of the genetic drivers of melanomagenesis in the last decade has led the World Health Organization to reclassify melanoma subtypes by their molecular pathways rather than traditional clinical and histopathologic features. Despite this significant advance, the genomic and transcriptomic drivers of metastatic progression are less well characterized. This review describes the known molecular pathways of cutaneous and uveal melanoma progression, highlights recently identified pathways and mediators of metastasis, and touches on the influence of the tumor microenvironment on metastatic progression and treatment resistance. While targeted therapies and immune checkpoint blockade have significantly aided in the treatment of advanced disease, acquired drug resistance remains an unfortunately common problem, and there is still a great need to identify potential prognostic markers and novel therapeutic targets to aid in such cases.

Reproductive history and blood cell DNA methylation later in life: the Young Finns Study

Background

Women with a history of complications of pregnancy, including hypertensive disorders, gestational diabetes or an infant fetal growth restriction or preterm birth, are at higher risk for cardiovascular disease later in life. We aimed to examine differences in maternal DNA methylation following pregnancy complications.

Methods

Data on women participating in the Young Finns study (n = 836) were linked to the national birth registry. DNA methylation in whole blood was assessed using the Infinium Methylation EPIC BeadChip. Epigenome-wide analysis was conducted on differential CpG methylation at 850 K sites. Reproductive history was also modeled as a predictor of four epigenetic age indices.

Results

Fourteen significant differentially methylated sites were found associated with both history of pre-eclampsia and overall hypertensive disorders of pregnancy. No associations were found between reproductive history and any epigenetic age acceleration measure.

Conclusions

Differences in epigenetic methylation profiles could represent pre-existing risk factors, or changes that occurred as a result of experiencing these complications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01215-1.

Deep Proteomic Analysis on Biobanked Paraffine-Archived Melanoma with Prognostic/Predictive Biomarker Read-Out

The discovery of novel protein biomarkers in melanoma is crucial. Our introduction of formalin-fixed paraffin-embedded (FFPE) tumor protocol provides new opportunities to understand the progression of melanoma and open the possibility to screen thousands of FFPE samples deposited in tumor biobanks and available at hospital pathology departments. In our retrospective biobank pilot study, 90 FFPE samples from 77 patients were processed. Protein quantitation was performed by high-resolution mass spectrometry and validated by histopathologic analysis. The global protein expression formed six sample clusters. Proteins such as TRAF6 and ARMC10 were upregulated in clusters with enrichment for shorter survival, and proteins such as AIFI1 were upregulated in clusters with enrichment for longer survival. The cohort's heterogeneity was addressed by comparing primary and metastasis samples, as well comparing clinical stages. Within immunotherapy and targeted therapy subgroups, the upregulation of the VEGFA-VEGFR2 pathway, RNA splicing, increased activity of immune cells, extracellular matrix, and metabolic pathways were positively associated with patient outcome. To summarize, we were able to (i) link global protein expression profiles to survival, and they proved to be an independent prognostic indicator, as well as (ii) identify proteins that are potential predictors of a patient's response to immunotherapy and targeted therapy, suggesting new opportunities for precision medicine developments.

A Novel Prognostic and Predictive Signature for Lung Adenocarcinoma Derived from Combined Hypoxia and Infiltrating Immune Cell-Related Genes in TCGA Patients

Background

The hypoxia and immune status of the lung adenocarcinoma (LUAD) microenvironment appear to have combined impacts on prognosis. Therefore, deriving a prognostic signature by integrating hypoxia- and immune infiltrating cell-related genes (H&IICRGs) may add value over prognostic indices derived from genes driving either process alone.

Methods

Differentially expressed H&IICRGs (DE-H&IICRGs) were identified in The Cancer Genome Atlas transcriptomic data using limma, CIBERSORT, weighted gene co-expression network analysis, and intersection analysis. A stepwise Cox regression model was constructed to identify prognostic genes and to produce a gene signature based on DE-H&IICRGs. The potential biological functions associated with the gene signature were explored using functional enrichment analysis. The prognostic signature was externally validated in a separate cohort from the Gene Expression Omnibus database.

Results

Five prognostic genes associated with overall survival in LUAD were used in the DE-H&IICRG-based prognostic signature. Patients in the high-risk group had an inferior prognosis, which was validated in an independent external cohort, and had lower expression of most immune checkpoint genes. In multivariate analysis, only risk score and T stage were independent prognostic factors. Differentially expressed genes (DEGs) associated with the risk score were enriched for pathways related to cell cycle, hypoxia regulation, and immune response. TIDE analyses showed that low-risk LUAD patients might also respond better to immunotherapy.

Conclusion

This study establishes and validates a prognostic profile for LUAD patients that combines hypoxia and immune infiltrating cell-related genes. This signature may have clinical application both for prognostication and guiding individualized immunotherapy.

Comparative mRNA/micro-RNA co-expression network drives melanomagenesis by promoting epithelial-mesenchymal transition and vasculogenic mimicry signaling

This study aimed to identify a novel disease-associated differentially co-expressed mRNA-microRNA (miRNA) that is associated with vasculogenic mimicry (VM) and epithelial-to-mesenchymal transition (EMT) network at different stages of melanoma. By applying weighted gene co-expression network analysis, we constructed a VM+EMT biological network with the available microarray dataset downloaded from a public database. Quantitative real-time PCR, immunohistochemical staining, and CD31-periodic acid solution dual staining were performed to confirm the expression of genes associated with EMT and VM formation in subjects with malignant melanoma (n = 18) and primary melanoma (n = 13) and in healthy subjects (n = 10). Our findings suggested that phosphatidylserine-specific phospholipase A1-alpha (PLA1A) and dermokine (DMKN) genes function as oncogenes that trigger VM and EMT processes during melanomagenesis on interaction with miR-370, miR-563, and miR-770-5p. PLA1A and DMKN genes can be considered potential VM+EMT network-based diagnostic biomarkers for distinguishing between melanoma patients. We postulate that a network with altered PLA1A/miR-563 and DMNK/miR-770-5p/miR-370 may contribute to melanomagenesis by triggering the EMT signaling pathway and VM formation. This study provides a potentially valuable approach for the early diagnosis and prognosis of melanoma progression.

GNG7 and ADCY1 as diagnostic and prognostic biomarkers for pancreatic adenocarcinoma through bioinformatic-based analyses

Pancreatic adenocarcinoma (PAAD) is one of the most lethal malignant tumors in the world. The GSE55643 and GSE15471 microarray datasets were downloaded to screen the diagnostic and prognostic biomarkers for PAAD. 143 downregulated genes and 118 upregulated genes were obtained. Next, we performed gene ontology (GO) and The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis on these genes and constructed a protein-protein interaction (PPI) network. We screened out two important clusters of genes, including 13 upregulated and 5 downregulated genes. After the survival analysis, 3 downregulated genes and 10 upregulated genes were identified as the selected key genes. The KEGG analysis on 13 selected genes showed that GNG7 and ADCY1 enriched in the Pathway in Cancer. Next, the diagnostic and prognostic value of GNG7 and ADCY1 was investigated using independent cohort of the Cancer Genome Atlas (TCGA), GSE84129 and GSE62452. We observed that the expression of the GNG7 and ADCY1 was decreased in PAAD. The diagnostic receiver operating characteristic (ROC) analysis indicated that the GNG7 and ADCY1 could serve as sensitive diagnostic markers in PAAD. Survival analysis suggested that expression of GNG7, ADCY1 were significantly associated with PAAD overall survival (OS). The multivariate cox regression analysis showed that the expression of GNG7, ADCY1 were independent risk factors for PAAD OS. Our study indicated GNG7 and ADCY1 may be potential diagnostic and prognostic biomarkers in patients with PAAD.

Differential DNA methylation analysis reveals key genes in Chinese Qingyu and Landrace pigs

The Chinese Qingyu pig is a typical domestic fatty pig breed and an invaluable indigenous genetic resource in China. Compared with the Landrace pig, the Qingyu pig has unique meat characteristics, including muscle development, intramuscular fat, and other meat quality traits. At present, few studies have explored epigenetic differences due to DNA methylation between the Qingyu pig and the Landrace pig. In this study, 30 Qingyu pigs and 31 Landrace pigs were subjected to reduced representation bisulfite sequencing (RRBS). Genome-wide differential DNA methylation analysis was conducted. Six genomic regions, including regions on Sus scrofa chromosome (SSC) 1: 266.09-274.23 Mb, SSC5: 0.88-10.68 Mb, SSC8: 41.23-48.51 Mb, SSC12: 45.43-54.38 Mb, SSC13: 202.15-207.95 Mb, and SSC14: 126.43-139.85 Mb, were regarded as key regions that may be associated with phenotypic differences between the Qingyu pig and the Landrace pig. Furthermore, according to further analysis, five differentially methylated genes (ADCY1, FUBP3, GRIN2B, KIT, and PIK3R6) were identified as key candidate genes that might be associated with meat characteristics. Our findings provide new insights into the differences in DNA methylation between the Qingyu pig and the Landrace pig. These results enrich the epigenetic research of the Chinese Qingyu pig.

Circular RNA hsa_circ_0000277 sequesters miR-4766-5p to upregulate LAMA1 and promote esophageal carcinoma progression

Growing evidence has indicated that circular RNAs (circRNAs) play a pivotal role as functional RNAs in diverse cancers. However, most circRNAs involved in esophageal squamous cell carcinoma (ESCC) remain undefined, and the underlying molecular mechanisms mediated by circRNAs are largely unclear. Here, we screened human circRNA expression profiles in ESCC tissues and found significantly increased expression of hsa_circ_0000277 (termed circPDE3B) in ESCC tissues and cell lines compared to the normal controls. Moreover, higher circPDE3B expression in patients with ESCC was correlated with advanced tumor-node-metastasis (TNM) stage and dismal prognosis. Functional experiments demonstrated that circPDE3B promoted the tumorigenesis and metastasis of ESCC cells in vitro and in vivo. Mechanistically, bioinformatics analysis, a dual-luciferase reporter assay, and anti-AGO2 RNA immunoprecipitation showed that circPDE3B could act as a competing endogenous RNA (ceRNA) by harboring miR-4766-5p to eliminate the inhibitory effect on the target gene laminin α1 (LAMA1). In addition, LAMA1 was significantly upregulated in ESCC tissues and was positively associated with the aggressive oncogenic phenotype. More importantly, rescue experiments revealed that the oncogenic role of circPDE3B in ESCC is partly dependent on the miR-4766-5p/LAMA1 axis. Furthermore, bioinformatics analysis combined with validation experiments showed that epithelial-mesenchymal transition (EMT) activation was involved in the oncogenic functions of the circPDE3B-miR-4766-5p/LAMA1 axis in ESCC. Taken together, we demonstrate for the first time that the circPDE3B/miR-4766-5p/LAMA1 axis functions as an oncogenic factor in promoting ESCC cell proliferation, migration, and invasion by inducing EMT, implying its potential prognostic and therapeutic significance in ESCC.

Genome-wide DNA methylation analysis in Chinese Chenghua and Yorkshire pigs

Background

The Chinese Chenghua pig (CHP) is a typical Chinese domestic fatty pig breed with superior meat quality characteristics, while the Yorkshire pig (YP) has the characteristics of fast growth and a high rate of lean meat. Long term natural selection and artificial selection resulted in great phenotypic differences between the two breeds, including growth, development, production performance, meat quality, and coat color. However, genome-wide DNA methylation differences between CHP and YP remain unclear.

Results

DNA methylation data were generated for muscle tissues of CHP and YP using reduced representation bisulfite sequencing (RRBS). In this study, a total of 2,416,211 CpG sites were identified. Besides, the genome-wide DNA methylation analysis revealed 722 differentially methylated regions (DMRs) and 466 differentially methylated genes (DMGs) in pairwise CHP vs. YP comparison. Six key genomic regions (Sus scrofa chromosome (SSC)1:253.47–274.23 Mb, SSC6:148.71–169.49 Mb, SSC7:0.25–9.86 Mb, SSC12:43.06–61.49 Mb, SSC14:126.43–140.95 Mb, and SSC18:49.17–54.54 Mb) containing multiple DMRs were identified, and differences of methylation patterns in these regions may be related to phenotypic differences between CHP and YP. Based on the functional analysis of DMGs, 8 DMGs (ADCY1, AGBL4, EXOC2, FUBP3, PAPPA2, PIK3R1, MGMT and MYH8) were considered as important candidate genes associated with muscle development and meat quality traits in pigs.

Conclusions

This study explored the difference in meat quality between CHP and YP from the epigenetic point of view, which has important reference significance for the local pork industry and pork food processing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12863-021-00977-0.

Cross-Talk Between the Adenylyl Cyclase/cAMP Pathway and Ca2+ Homeostasis

Cyclic AMP and Ca²⁺ are the first second or intracellular messengers identified, unveiling the cellular mechanisms activated by a plethora of extracellular signals, including hormones. Cyclic AMP generation is catalyzed by adenylyl cyclases (ACs), which convert ATP into cAMP and pyrophosphate. By the way, Ca²⁺, as energy, can neither be created nor be destroyed; Ca²⁺ can only be transported, from one compartment to another, or chelated by a variety of Ca²⁺-binding molecules. The fine regulation of cytosolic concentrations of cAMP and free Ca²⁺ is crucial in cell function and there is an intimate cross-talk between both messengers to fine-tune the cellular responses. Cancer is a multifactorial disease resulting from a combination of genetic and environmental factors. Frequent cases of cAMP and/or Ca²⁺ homeostasis remodeling have been described in cancer cells. In those tumoral cells, cAMP and Ca²⁺ signaling plays a crucial role in the development of hallmarks of cancer, including enhanced proliferation and migration, invasion, apoptosis resistance, or angiogenesis. This review summarizes the cross-talk between the ACs/cAMP and Ca²⁺ intracellular pathways with special attention to the functional and reciprocal regulation between Orai1 and AC8 in normal and cancer cells.

Identification of Metastasis-Associated MicroRNAs in Metastatic Melanoma by miRNA Expression Profile and Experimental Validation

It is reported that microRNAs (miRNA) have paramount functions in many cellular biological processes, development, metabolism, differentiation, survival, proliferation, and apoptosis included, some of which are involved in metastasis of tumors, such as melanoma. Here, three metastasis-associated miRNAs, miR-18a-5p (upregulated), miR-155-5p (downregulated), and miR-93-5p (upregulated), were identified from a total of 63 different expression miRNAs (DEMs) in metastatic melanoma compared with primary melanoma. We predicted 262 target genes of miR-18a-5p, 904 miR-155-5p target genes, and 1220 miR-93-5p target genes. They participated in pathways concerning melanoma, such as TNF signaling pathway, pathways in cancer, FoxO signaling pathway, cell cycle, Hippo signaling pathway, and TGF-beta signaling pathway. We identified the top 10 hub nodes whose degrees were higher for each survival-associated miRNA as hub genes through constructing the PPI network. Using the selected miRNA and the hub genes, we constructed the miRNA-hub gene network, and PTEN and CCND1 were found to be regulated by all three miRNAs. Of note, miR-155-5p was obviously downregulated in metastatic melanoma tissues, and miR-18a-5p and miR-93-5p were obviously regulated positively in metastatic melanoma tissues. In validating experiments, miR-155-5p's overexpression inhibited miR-18a-5p's and miR-93-5p's expression, which could all significantly reduce SK-MEL-28 cells' invasive ability. Finally, miR-93-5p and its potential target gene UBC were selected for further validation. We found that miR-93-5p's inhibition could reduce SK-MEL-28 cell's invasive ability through upregulated the expression of UBC, and the anti-invasive effect was reserved by downregulation of UBC. The results show that the selected three metastasis-associated miRNAs participate in the process of melanoma metastasis via regulating their target genes, providing a potential molecular mechanism for this disease.

TMEM106C contributes to the malignant characteristics and poor prognosis of hepatocellular carcinoma

Transmembrane protein (TMEM) is a kind of integral membrane protein that spans biological membranes. The functions of most members of the TMEM family are unknown. Here, we conducted bioinformatic analysis and biological validation to investigate the role of TMEM106C in HCC. First, GEPIA and Oncomine^TM were used to analyze TMEM106C expression, which was verified by real-time PCR and western blot analyses. Then, the biological functions of TMEM106C were explored by CCK8 and transwell assays. The prognostic value of TMEM106C was analyzed by UALCAN. LinkedOmics was used to analyze TMEM106C pathways generated by Gene Ontology. A protein-protein interaction network (PPI) was constructed by GeneMANIA. We demonstrated that TMEM106C was overexpressed in HCC and that inhibition of TMEM106C significantly suppressed the proliferation and metastasis of HCC through targeting CENPM and DLC-1. Upregulation of TMEM106C was closely correlated with sex, tumor stage, tumor grade and prognosis. Overexpression of TMEM106C was linked to functional networks involving organelle fission and cell cycle signaling pathways through the regulation of CDK kinases, E2F1 transcription factors and miRNAs. Our data demonstrated that TMEM106C contributes to malignant characteristics and poor prognosis in HCC, which may serve as a prognostic biomarker and potential therapeutic target.

Comprehensive analysis and identification of key genes and signaling pathways in the occurrence and metastasis of cutaneous melanoma

Background

Melanoma is a malignant tumor of melanocytes, and the incidence has increased faster than any other cancer over the past half century. Most primary melanoma can be cured by local excision, but metastatic melanoma has a poor prognosis. Cutaneous melanoma (CM) is prone to metastasis, so the research on the mechanism of melanoma occurrence and metastasis will be beneficial to diagnose early, improve treatment, and prolong life survival. In this study, we compared the gene expression of normal skin (N), primary cutaneous melanoma (PM) and metastatic cutaneous melanoma (MM) in the Gene Expression Omnibus (GEO) database. Then we identified the key genes and molecular pathways that may be involved in the development and metastasis of cutaneous melanoma, thus to discover potential markers or therapeutic targets.

Methods

Three gene expression profiles (GSE7553, GSE15605 and GSE46517) were downloaded from the GEO database, which contained 225 tissue samples. R software identified the differentially expressed genes (DEGs) between pairs of N, PM and MM samples in the three sets of data. Subsequently, we analyzed the gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of the DEGs, and constructed a protein-protein interaction (PPI) network. MCODE was used to seek the most important modules in PPI network, and then the GO function and KEGG pathway of them were analyzed. Finally, the hub genes were calculated by the cytoHubba in Cytoscape software. The Cancer Genome Atlas (TCGA) data were analyzed using UALCAN and GEPIA to validate the hub genes and analyze the prognosis of patients.

Results

A total of 134, 317 and 147 DEGs were identified between N, PM and MM in pair. GO functions and KEGG pathways analysis results showed that the upregulated DEGs mainly concentrated in cell division, spindle microtubule, protein kinase activity and the pathway of transcriptional misregulation in cancer. The downregulated DEGs occurred in epidermis development, extracellular exosome, structural molecule activity, metabolic pathways and p53 signaling pathway. The PPI network obtained the most important module, whose GO function and KEGG pathway were enriched in oxidoreductase activity, cell division, cell exosomes, protein binding, structural molecule activity, and metabolic pathways. 14, 18 and 18 DEGs were identified respectively as the hub genes between N, PM and MM, and TCGA data confirmed the expression differences of hub genes. In addition, the overall survival curve of hub genes showed that the differences in these genes may lead to a significant decrease in overall survival of melanoma patients.

Conclusions

In this study, several hub genes were found from normal skin, primary melanoma and metastatic melanoma samples. These hub genes may play an important role in the production, invasion, recurrence or death of CM, and may provide new ideas and potential targets for its diagnosis or treatment.

Upregulation of centromere protein M promotes tumorigenesis: A potential predictive target for cancer in humans

Centromere protein M (CENPM), a protein required for chromosome separation, is involved in in mitosis. However, little has been reported about the roles of CENPM in various types of cancer. The present study identified that the mRNA expression levels of CENPM were significantly upregulated in 14 types of human cancer and identified a positive association between CENPM mRNA expression and patient mortality using the Oncomine, Gene Expression Profiling Interactive Analysis, Human Protein Atlas and Kaplan‑Meier Plotter databases. A protein interaction network constructed with CENPM‑interacting genes obtained from the cBioPortal demonstrated that nine genes participating in the cell cycle served key roles in the function of CENPM. Cell cycle analysis, reverse transcription‑quantitative polymerase chain reaction, a Cell Counting Kit‑8‑based proliferation assay and a terminal deoxynucleotidyl transferase dUTP nick end labelling assay further revealed the tumorigenic and carcinogenic roles of CENPM in vitro. In addition, it was identified that the mRNA expression levels of five of the nine identified genes were significantly associated with CENPM in MCF7 cells and that CENPM was rarely mutated among various types of human cancer. In conclusion, the data from the present study revealed that CENPM exerted its pro‑tumorigenic function by regulating cell cycle‑associated protein expression and suggested that CENPM could be used as a prognostic marker for breast cancer.

Association of PRKCA expression and polymorphisms with layer duck eggshell quality

1. Eggshell quality is important for the poultry industry. Calcium is deposited during eggshell formation, and protein kinase C alpha (PRKCA) is involved in transmembrane transport of calcium ions in cells. However, the biological function of PRKCA in poultry is still not understood. Therefore, the aim of this study was to explore the association of mRNA expression and single nucleotide polymorphisms (SNPs) of the PRKCA gene with eggshell quality in laying ducks. 2. The mRNA expression and SNPs of the PRKCA gene were detected by real-time fluorescence quantitative PCR (qRT-PCR) and sequencing of PCR products in 45-week-old female Sansui ducks, which is a high production layer duck breed in China. The association of mRNA expression and SNPs in the PRKCA gene with layer duck eggshell traits was analysed using SPSS (v18.0) software. 3. The results demonstrated that PRKCA mRNA was widely expressed in all examined tissues, and expression was highest in kidney and lowest in the gizzard. Furthermore, the PRKCA mRNA level in uterus was significantly positively correlated with eggshell strength and eggshell weight (P < 0.05). Three novel SNPs, the synonymous mutations of g.9571770 T > C in exon 5, g.9583222 C > T and g.9583227 G > A in exon 7, were found in the PRKCA gene, giving four haplotypes and 10 diplotypes, which affected the mRNA secondary structure and free energy. The g.9583222 C > T and g.9583227 G > A mutations were significantly associated with eggshell strength (P < 0.05). Diplotype H1H1 was advantageous for increasing the strength and thickness of an eggshell. 4. In conclusion, the study showed that the mRNA transcription and genetic variation in the PRKCA gene could significantly affect the strength of duck eggshell and that the PRKCA gene is an important candidate gene for improving eggshell quality in poultry.

Cancer cell line-specific protein profiles in extracellular vesicles identified by proteomics

Extracellular vesicles (EVs), are important for intercellular communication in both physiological and pathological processes. To explore the potential of cancer derived EVs as disease biomarkers for diagnosis, monitoring, and treatment decision, it is necessary to thoroughly characterize their biomolecular content. The aim of the study was to characterize and compare the protein content of EVs derived from three different cancer cell lines in search of a specific molecular signature, with emphasis on proteins related to the carcinogenic process. Oral squamous cell carcinoma (OSCC), pancreatic ductal adenocarcinoma (PDAC) and melanoma brain metastasis cell lines were cultured in CELLine AD1000 flasks. EVs were isolated by ultrafiltration and size-exclusion chromatography and characterized. Next, the isolated EVs underwent liquid chromatography-mass spectrometry (LC-MS) analysis for protein identification. Functional enrichment analysis was performed for a more general overview of the biological processes involved. More than 600 different proteins were identified in EVs from each particular cell line. Here, 14%, 10%, and 24% of the identified proteins were unique in OSCC, PDAC, and melanoma vesicles, respectively. A specific protein profile was discovered for each cell line, e.g., EGFR in OSCC, Muc5AC in PDAC, and FN1 in melanoma vesicles. Nevertheless, 25% of all the identified proteins were common to all cell lines. Functional enrichment analysis linked the proteins in each data set to biological processes such as "biological adhesion", "cell motility", and "cellular component biogenesis". EV proteomics discovered cancer-specific protein profiles, with proteins involved in processes promoting tumor progression. In addition, the biological processes associated to the melanoma-derived EVs were distinct from the ones linked to the EVs isolated from OSCC and PDAC. The malignancy specific biomolecular cues in EVs may have potential applications as diagnostic biomarkers and in therapy.

Upregulation of CENPM facilitates tumor metastasis via the mTOR/p70S6K signaling pathway in pancreatic cancer

Pancreatic cancer is a severe disease with high morbidity and mortality. However, the primary molecular mechanisms of pancreatic tumor formation and progression remain unclear. The present study using sequencing technology revealed that the centromere protein M (CENPM) gene was overexpressed in pancreatic cancer tissues. CENPM is one of the components of a complex that plays a central role in kinetochore protein assembly, mitotic progression and chromosome segregation. However, the biological function of CENPM in pancreatic cancer has yet to be determined. Hence, two effective siRNAs were designed to knock down CENPM. Notably, downregulation of CENPM inhibited pancreatic cancer cell proliferation, altered the cell cycle and limited pancreatic cancer cell migration and invasion via the mTOR/p70S6K signaling pathway. This research provides new evidence that CENPM overexpression plays a significant role in the progression of pancreatic cancer. Overall, the present findings indicated that CENPM may be a significant biomarker for predicting the development and progression of pancreatic malignancy.

Short-Term Microgravity Influences Cell Adhesion in Human Breast Cancer Cells

With the commercialization of spaceflight and the exploration of space, it is important to understand the changes occurring in human cells exposed to real microgravity (r-µg) conditions. We examined the influence of r-µg, simulated microgravity (s-µg, incubator random positioning machine (iRPM)), hypergravity (hyper-g), and vibration (VIB) on triple-negative breast cancer (TNBC) cells (MDA-MB-231 cell line) with the aim to study early changes in the gene expression of factors associated with cell adhesion, apoptosis, nuclear factor "kappa-light-chain-enhancer" of activated B-cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling. We had the opportunity to attend a parabolic flight (PF) mission and to study changes in RNA transcription in the MDA-MB cells exposed to PF maneuvers (29th Deutsches Zentrum für Luft- und Raumfahrt (DLR) PF campaign). PF maneuvers induced an early up-regulation of ICAM1, CD44 and ERK1 mRNAs after the first parabola (P1) and a delayed upregulation of NFKB1, NFKBIA, NFKBIB, and FAK1 after the last parabola (P31). ICAM-1, VCAM-1 and CD44 protein levels were elevated, whereas the NF-κB subunit p-65 and annexin-A2 protein levels were reduced after the 31st parabola (P31). The PRKCA, RAF1, BAX mRNA were not changed and cleaved caspase-3 was not detectable in MDA-MB-231 cells exposed to PF maneuvers. Hyper-g-exposure of the cells elevated the expression of CD44 and NFKBIA mRNAs, iRPM-exposure downregulated ANXA2 and BAX, whereas VIB did not affect the TNBC cells. The early changes in ICAM-1 and VCAM-1 and the rapid decrease in the NF-κB subunit p-65 might be considered as fast-reacting, gravity-regulated and cell-protective mechanisms of TNBC cells exposed to altered gravity conditions. This data suggest a key role for the detected gravity-signaling elements in three-dimensional growth and metastasis.

A perspective profile of ADCY1 in cAMP signaling with drug-resistance in lung cancer

Adenylate cyclase 1 (ADCY1 or AC1) is a member of ADCY superfamily and was primarily found to be expressed in the brain. ADCY1 is responsible for catalyzing ATP to cyclic AMP (cAMP). As a secondary messenger, cAMP can regulate plenty of cellular activities. cAMP can perform its regulation in cellular transport through the binding to cAMP dependent protein kinases (PKAs), cAMP-activated guanine exchange factors (EPACs) and cyclic nucleotide-gated channels functioning in transduction of sensory signals (CNGs). Lung cancer is one of the leading factors of cancer-related death worldwide. Platinum-based chemotherapy is the first-line treatment for advanced lung cancer patients. In addition, surgical treatment, radiation treatment, and molecular targeted therapy are also therapeutic options for lung cancer patients in clinical settings. However, drug resistance and toxicity are the major obstacles that affect chemotherapy outcome and prognosis of lung cancer patients. And the therapeutic efficiency and adverse effects are varying with each individual. In recent years, investigations based on genetic sequencing have revealed the emerging role of ADCY1 mutations in affecting drug efficiency in various cancers such as lung cancer, esophageal cancer and colorectal cancer. The potential function of ADCY1 in chemotherapy resistance is of great importance to be noticed and investigated.