MTSS1 and SCAMP1 cooperate to prevent invasion in breast cancer

SCAMP1 silencing inhibits proliferation by attenuating multiple pro-survival signaling pathways in gastric cancer

Secretory carrier-associated membrane protein 1 (SCAMP1) is the most universally expressed member of the SCAMP family, and its ability to facilitate endocytosis was demonstrated approximately two decades ago. Nevertheless, its roles in cancer biology are largely unknown, although its expression is significantly increased in most cancer types. Herein, we examined the expression of SCAMP1 in gastric cancer (GC) tissues and found that it was aberrantly increased and positively correlated with tumor size and lymph node metastasis. More importantly, increased SCAMP1 expression was associated with poor prognosis in patients with GC. Functional experiments demonstrated that SCAMP1 knockdown markedly suppressed the proliferation of GC cells in vitro and in vivo. RNA sequencing assays demonstrated that SCAMP1 knockdown altered the expression profile of GC cells, and a significant portion of the altered genes were enriched in receptor tyrosine kinases and their related downstream signaling pathways. Immunoblotting confirmed that the Akt/MAPK/Stat signaling pathway was strongly attenuated in GC cells with SCAMP1 depletion. Taken together, these results demonstrated that SCAMP1 drives hyperproliferation in GC cells, thus suggesting that further investigation into the mechanisms and translational value of SCAMP1 in treating patients with GC is warranted.

The mechanisms behind the dual role of long non-coding RNA (lncRNA) metastasis suppressor-1 in human tumors: Shedding light on the molecular mechanisms

When the expression levels of metastasis suppressor-1 (MTSS1) were discovered to be downregulated in a metastatic cancer cell line in 2002, it was proposed that MTSS1 functioned as a suppressor of metastasis. The 755 amino acid long protein MTSS1 connects to actin and organizes the cytoskeleton. Its gene is located on human chromosome 8q24. The suppressor of metastasis in metastatic cancer was first found to be MTSS1. Subsequent reports revealed that MTSS1 is linked to the prevention of metastasis in a variety of cancer types, including hematopoietic cancers like diffuse large B cell lymphoma and esophageal, pancreatic, and stomach cancers. Remarkably, conflicting results have also been documented. For instance, it has been reported that MTSS1 expression levels are elevated in a subset of melanomas, hepatocellular carcinoma associated with hepatitis B, head and neck squamous cell carcinoma, and lung squamous cell carcinoma. This article provides an overview of the pathological effects of lncRNA MTSS1 dysregulation in cancer. In order to facilitate the development of MTSS1-based therapeutic targeting, we also shed light on the current understanding of MTS1.

Screening and identification of hub genes of scar physique via weighted gene co-expression network analysis

Scar physique refers to the abnormal repair of skin injury in some people, which may easily lead to keloid or hypertrophic scar. However, the mechanism of scar physique is still unclear. GSE108110 was obtained from the gene expression omnibus database. Differently expression genes (DEGs) between normal skin tissue of non-scar physique individuals and normal skin tissue of scar physique individuals were screened by R package "limma". Weighted gene co-expression network analysis was performed to find highly relevant gene modules. Functional annotation of DEGs was made. Protein-protein interaction network was constructed, and the identification and analysis of hub DEGs were performed, including identification of hub DEGs associated with scar diseases, MiRNA of hub DEGs prediction, and functional annotation of miRNA. A total of 1389 up-regulate DEGs and 1672 down-regulate DEGs were screened. weighted gene co-expression network analysis analysis showed that the dendrogram and heatmap were used to quantify module similarity by correlation. The associations between clinic traits and the modules were identified based on the correlation between module and scar physique. Eight common hub genes were obtained. The comparative toxicogenomics database shows common hub genes associated with scar tissue. Gene ontology and Kyoto encyclopedia of genes and genomes analysis were significantly enriched in "fibroblast growth factor receptor signaling pathway", "epidermal growth factor receptor signaling pathway", "G1/S transition of mitotic cell cycle", protein polyubiquitination", and others. The 8 hub genes might be involved in the development of scarring and used as early diagnosis, prevention and treatment of scar physique.

BORIS/CTCFL-mediated chromatin accessibility alterations promote a pro-invasive transcriptional signature in melanoma cells

Melanoma is the deadliest form of skin cancer, due to its tendency to metastasize early. Brother of regulator of imprinted sites (BORIS), also known as CCCTC binding factor-like (CTCFL), is a transcription regulator that becomes ectopically expressed in melanoma. We recently showed that BORIS contributes to melanoma phenotype switching by altering the gene expression program of melanoma cells from an intermediate melanocytic state toward a more mesenchymal-like state. However, the mechanism underlying this transcriptional switch remains unclear. Here, ATAC-seq was used to study BORIS-mediated chromatin accessibility alterations in melanoma cells harboring an intermediate melanocytic state. The gene set that gained promoter accessibility, following ectopic BORIS expression, showed enrichment for biological processes associated with melanoma invasion, while promoters of genes associated with proliferation showed reduced accessibility. Integration of ATAC-seq and RNA-seq data demonstrated that increased chromatin accessibility was associated with transcriptional upregulation of genes involved in tumor progression processes, and the aberrant activation of oncogenic transcription factors, while reduced chromatin accessibility and downregulated genes were associated with repressed activity of tumor suppressors and proliferation factors. Together, these findings indicate that BORIS mediates transcriptional reprogramming in melanoma cells by altering chromatin accessibility and gene expression, shifting the cellular transcription landscape of melanoma cells toward a mesenchymal-like genetic signature.

MTSS1 curtails lung adenocarcinoma immune evasion by promoting AIP4-mediated PD-L1 monoubiquitination and lysosomal degradation

Immune checkpoint blockade (ICB) therapy targeting PD-1/PD-L1 has shown durable clinical benefits in lung cancer. However, many patients respond poorly to ICB treatment, underscoring an incomplete understanding of PD-L1 regulation and therapy resistance. Here, we find that MTSS1 is downregulated in lung adenocarcinoma, leading to PD-L1 upregulation, impairment of CD8⁺ lymphocyte function, and enhanced tumor progression. MTSS1 downregulation correlates with improved ICB efficacy in patients. Mechanistically, MTSS1 interacts with the E3 ligase AIP4 for PD-L1 monoubiquitination at Lysine 263, leading to PD-L1 endocytic sorting and lysosomal degradation. In addition, EGFR-KRAS signaling in lung adenocarcinoma suppresses MTSS1 and upregulates PD-L1. More importantly, combining AIP4-targeting via the clinical antidepressant drug clomipramine and ICB treatment improves therapy response and effectively suppresses the growth of ICB-resistant tumors in immunocompetent mice and humanized mice. Overall, our study discovers an MTSS1-AIP4 axis for PD-L1 monoubiquitination and reveals a potential combinatory therapy with antidepressants and ICB.

LncRNA SCAMP1 disrupts the balance between miR-26a-5p and ZEB2 to promote osteosarcoma cell viability and invasion

Osteosarcoma often occurs in children and adolescents and affects their health. The survival rate of osteosarcoma patients is unsatisfactory due to the lack of early detection and metastasis development and drug resistance. Hence, dissection of molecular insight into osteosarcoma initiation and progression is pivotal to provide the new therapeutic strategy. In recent years, long noncoding RNAs (lncRNAs) have burst into stage in osteosarcoma development and malignant behaviors. LncRNA SCAMP1 has been discovered to play an essential role in carcinogenesis and progression. However, the mechanisms of lncRNA SCAMP1-involved tumorigenesis have not been reported in human osteosarcoma. In this study, we utilized multiple cellular biological approaches to determine the function of lncRNA SCAMP1 in osteosarcoma cells. Moreover, we performed several molecular biological approaches to define the mechanism by which lncRNA SCAMP1 regulated cell viability and invasion in osteosarcoma. We dissected that lncRNA SCAMP1 promoted progression of osteosarcoma via modulation of miR-26a-5p/ZEB2 axis. In conclusion, targeting lncRNA SCAMP1 and its downstream targets, miR-26a-5p and ZEB2, might be a useful approach for osteosarcoma therapy.

Golgi Complex: A Signaling Hub in Cancer

The Golgi Complex is the central hub in the endomembrane system and serves not only as a biosynthetic and processing center but also as a trafficking and sorting station for glycoproteins and lipids. In addition, it is an active signaling hub involved in the regulation of multiple cellular processes, including cell polarity, motility, growth, autophagy, apoptosis, inflammation, DNA repair and stress responses. As such, the dysregulation of the Golgi Complex-centered signaling cascades contributes to the onset of several pathological conditions, including cancer. This review summarizes the current knowledge on the signaling pathways regulated by the Golgi Complex and implicated in promoting cancer hallmarks and tumor progression.

SCAMP2/5 as diagnostic and prognostic markers for acute myeloid leukemia

The secretory carrier-associated membrane proteins (SCAMPs) are associated with the development of multiple human cancers. The role of SCAMPs in acute myeloid leukemia (AML), however, remains to be identified. In the present study, we explored expression patterns and prognostic value of SCAMPs and network analysis of SCAMPs-related signaling pathways in AML using Oncomine, GEPIA, cBioPortal, LinkedOmics, DAVID and Metascape databases. Genetic alteration analysis revealed that the mutation rate of SCAMP genes was below 1% (9/1272) in AML, and there was no significant correlation between SCAMPs gene mutation and AML prognosis. However, the SCAMP2/5 mRNA levels were significantly higher in AML patients than in healthy controls. Moreover, high mRNA expressions of SCAMP2/4/5 were associated with poor overall survival, which might be due to that SCAMP2/4/5 and their co-expressed genes were associated with multiple pathways related to tumorigenesis and progression, including human T-cell leukemia virus 1 infection, acute myeloid leukemia, mTOR and NF-kappa B signaling pathways. These results suggest that SCAMP2/4/5 are potential prognostic markers for AML, and that SCAMP2 and SCAMP5 individually or in combination may be used as diagnostic markers for AML.

GJA1 rs2071165 A > G Variant Increased Gastric Cancer Risk in Females of Northwest China: A Case-Control Study

Gastric cancer (GC) is one of the most common malignancies, and its incidence rates vary widely between men and women. Previous studies have suggested that connexin 43 (Cx43, encoded by gap junction protein alpha 1 (GJA1)) and secretory carrier membrane protein 1 (SCAMP1) are key functional proteins in tumors. Herein, the association between GJA1 and SCAMP1 polymorphisms and GC susceptibility and prognosis was evaluated. A total of three single-nucleotide polymorphisms among 681GC patients and 756 controls were tested using the Agena MassARRAY RS1000 system, including GJA1 rs2071165, SCAMP1 rs4530741, and SCAMP1 rs6874309. The strength of the association with GC risk was assessed by the odds ratios (ORs) and 95% confidence intervals (CIs) generated from the logistic regression model. Kaplan–Meier curve, long-rank tests, and a multivariate Cox proportional hazard model were used for prognosis analysis. The expression of GJA1 was assessed by immunohistochemistry. The GJA1 rs2071165 AA/AG genotype significantly increased the risk of GC in the female Chinese population (OR = 1.55, 95% CI = 1.03–2.32, p=0.034). Furthermore, the risk effect of GJA1 rs2071165 was more evident in the subgroups of female patients with GC, stratified by age, clinical stage, tumor size, and recurrence/metastasis. However, no obvious differences in Cx43 expression in GC tissues were observed between males and females. Furthermore, no significant association between SCAMP1 rs4530741 and rs6874309 polymorphisms and GC risk or prognosis was observed. In conclusion, this study suggests for the first time that the GJA1 rs2071165 polymorphism is associated with increased GC risk in females, revealing a potential new clinical marker for assessing GC risk in females.

Expression and prognostic analyses of SCAMPs in pancreatic adenocarcinoma

Due to the difficulties in early diagnosis of pancreatic adenocarcinoma (PAAD), many patients fail to receive optimal therapeutic regimens. The Secretory-Carrier-Membrane-Proteins (SCAMPs) are known to be dysregulated in a range of human diseases due to their characterized roles in mammalian cell exocytosis inferred from their functions as integral membrane proteins. However, the expression and prognostic value of SCAMPs in PAAD is poorly characterized. We compared cancer vs. healthy tissue and found that the expression of SCAMPs1-4 was upregulated in PAAD compared to normal tissue. In contrast, SCAMP5 expression was downregulated in PAAD. Moreover, the expression of SCAMPs1-4 was enhanced in PAAD cell lines according to Cancer Cell Line public database. Furthermore, the HPA, GEPIA databases and immunohistochemical analysis from 238 patients suggested that the loss of SCAMP1 led to improved overall survival (OS), whilst lower SCAMP5 levels led to a poorer OS. The univariate and multivariate analysis showed that SCAMP1 and SCAMP5 expression were independent prognostic factors of PAAD. In addition, the cBioPortal for Cancer Genomics, LinkedOmics datasets, and the GEPIA were used to identify the co-expression genes of SCAMP1,5 and the correlation between SCAMPs members. We conclude that SCAMPs 1 and 5 significantly represent promising diagnosis and prognostic biomarkers.

Glycoproteomic Analysis of Human Urinary Exosomes

Exosomes represent a class of secreted biological vesicles, which have recently gained attention due to their function as intertissue and interorganism transporters of genetic materials, small molecules, lipids, and proteins. Although the protein constituents of these exosomes are often glycosylated, a large-scale characterization of the glycoproteome has not yet been completed. This study identified 3144 unique glycosylation events belonging to 378 glycoproteins and 604 unique protein sites of glycosylation. With these data, we investigated the level of glycan microheterogeneity within the urinary exosomes, finding on average 5.9 glycans per site. The glycan family abundance on individual proteins showed subtle differences, providing an additional level of molecular characterization compared to the unmodified proteome. Finally, we show protein site-specific changes in regard to the common urinary glycoprotein, uromodulin. While uromodulin is an individual case, these same site-specific analyses provide a way forward for developing diagnostic glycoprotein biomarkers with urine as a noninvasive biological fluid. This study represents an important first step in understanding the functional urinary glycoproteome.

miRNA-182 regulated MTSS1 inhibits proliferation and invasion in Glioma Cells

Human glioma is the most common malignant and fatal primary tumor in the central nervous system. Currently, the high incidence and low cure rate of glioma make it a considerable threat to human health. Thus, elucidating the molecular mechanisms of glioma development and progression has become a major focus to identify new and effective biomarkers and improve the comprehensive neurosurgical treatment of glioma from the basic research and clinical perspectives. In our present study, we aimed to investigate the expression pattern and biological function of Metastasis suppressor protein 1(MTSS1) in glioma and to further explore whether miRNAs were involved in the deregulation of MTSS1. By overexpressing MTSS1 in highly malignant human glioma cells, we discovered a role for MTSS1 in suppressing the proliferation and invasion of glioma cells, and we showed that MTSS1 participated in transforming growth factor-beta 1 (TGF-β1) -induced epithelial-mesenchymal transition (EMT) in glioma cells. Biochemical analyses suggested that miR-182 may target MTSS1 and that miR-182 expression is negatively correlated with MTSS1 expression in glioma tissues. This finding was further confirmed by luciferase reporter experiments. Furthermore, a miR-182 inhibitor induced glioma cell proliferation and invasion by increasing MTSS1 expression. In conclusion, we believed that miR-182 modulates glioma cell migration and invasion by targeting the MTSS1 and suggested that miR-182 was a potential therapeutic target for gliomas.

EIF3J-AS1 promotes glioma cell growth via up-regulating ANXA11 through sponging miR-1343-3p

Background

Glioma is one prevalent malignant tumor originates from the central nervous system. Dysregulation of long non-coding RNAs (lncRNAs) has been found to be a molecular signature behind the pathology of a variety of cancers, including glioma. EIF3J antisense RNA 1 (EIF3J-AS1) is a novel lncRNA, whose performance in carcinogenesis has been unfolded. Nevertheless, the role of EIF3J-AS1 has never been investigated in glioma.

Methods

qRT-PCR analysis was adopted to evaluate the relative levels of RNAs. In vitro functional assays, including colony formation, EdU, TUNEL and caspase-3/8/9 activity assays were conducted to study the impacts of EIF3J-AS1 on glioma. Dual-luciferase activity assays, RNA pull down assay and RIP assay were performed to elucidate molecular interplay among genes.

Results

EIF3J-AS1 was overexpressed in glioma cell lines. Knockdown of EIF3J-AS1 hampered glioma malignant phenotypes. MiR-1343-3p could bind to EIF3J-AS1. Moreover, miR-1343-3p targeted Annexin A11 (ANXA11) in its 3′UTR region. Mechanistically, EIF3J-AS1 relieved ANXA11 from miR-1343-3p silencing in the EIF3J-AS1/miR-1343-3p/ANXA11 RNA induced silencing complex (RISC), thus eliciting promoting effects on glioma progression. MiR-1343-3p inhibitor and ANXA11 overexpression offset the inhibitory impacts of EIF3J-AS1 silencing on glioma development.

Conclusion

EIF3J-AS1/miR-1343-3p/ANXA11 axis significantly affected biological behaviors in glioma, suggesting new therapeutic target for glioma treatment.

Integrative Analysis of Membrane Proteome and MicroRNA Reveals Novel Lung Cancer Metastasis Biomarkers

Lung cancer is one of the most common human cancers both in incidence and mortality, with prognosis particularly poor in metastatic cases. Metastasis in lung cancer is a multifarious process driven by a complex regulatory landscape involving many mechanisms, genes, and proteins. Membrane proteins play a crucial role in the metastatic journey both inside tumor cells and the extra-cellular matrix and are a viable area of research focus with the potential to uncover biomarkers and drug targets. In this work we performed membrane proteome analysis of highly and poorly metastatic lung cells which integrated genomic, proteomic, and transcriptional data. A total of 1,762 membrane proteins were identified, and within this set, there were 163 proteins with significant changes between the two cell lines. We applied the Tied Diffusion through Interacting Events method to integrate the differentially expressed disease-related microRNAs and functionally dys-regulated membrane protein information to further explore the role of key membrane proteins and microRNAs in multi-omics context. Has-miR-137 was revealed as a key gene involved in the activity of membrane proteins by targeting MET and PXN, affecting membrane proteins through protein-protein interaction mechanism. Furthermore, we found that the membrane proteins CDH2, EGFR, ITGA3, ITGA5, ITGB1, and CALR may have significant effect on cancer prognosis and outcomes, which were further validated in vitro. Our study provides multi-omics-based network method of integrating microRNAs and membrane proteome information, and uncovers a differential molecular signatures of highly and poorly metastatic lung cancer cells; these molecules may serve as potential targets for giant-cell lung metastasis treatment and prognosis.

Long Noncoding RNA SCAMP1 Targets miR-137/CXCL12 Axis to Boost Cell Invasion and Angiogenesis in Ovarian Cancer

Ovarian cancer (OC) is one of gynecological malignancies that seriously affects women's health. Mounting evidence demonstrated that long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs) play important roles in various biological processes related to the pathogenesis of OC. This research aimed to investigate the regulatory mechanism of lncRNA SCAMP1/miR-137/CXCL12 (C-X-C motif chemokine ligand 12) axis on OC progression. In this study, we found that SCAMP1 was highly expressed in OC cells, which promoted OC cell invasion and angiogenesis. In addition, our research confirmed that SCAMP1 could bind with miR-137, and SCAMP1 sponged miR-137 to accelerate the progression of OC. We also observed that CXCL12 was a downstream target gene for miR-137, and miR-137 targeted CXCL12 to participate in the regulation of OC. Finally, through TCGA database, we found that SCAMP1 (or CXCL12) was upregulated as well as miR-137 was downregulated in OC tissues, and high (or low) level of them was associated with poor prognosis. miR-137 expression was negatively correlated with SCAMP1 (or CXCL12) expression, and SCAMP1 expression was positively correlated with CXCL12 expression in OC. In summary, our study clarified the role of SCAMP1/miR-137/CXCL12 axis in OC, and this finding may provide a potential therapeutic target of OC.

SCAMP3 Promotes Glioma Proliferation and Indicates Unfavorable Prognosis via Multiple Pathways

Introduction

The secretory carrier-associated membrane protein 3 (SCAMP3) is a component of post-Golgi membranes, functions as a protein carrier and is critical for subcellular protein transportation. Limited studies revealed an elevated expression of SCAMP3 in breast cancer and hepatocellular carcinoma; however, its role in glioma remains unknown. The aim of our study is to investigate the expression pattern and functional mechanisms of SCAMP3 in glioma.

Methods

mRNA and protein levels of SCAMP3 were examined in glioma tissues together with nontumorous brain tissues by using quantitative real-time-PCR and immunohistochemistry staining. The prognostic role of SCAMP3 in glioma was evaluated through univariate and multivariate analyses. In vitro and in vivo assays were conducted to explore the underlying mechanisms of SCAMP3-induced glioma progression.

Results

The expression level of SCAMP3 was higher in glioma tissues than that in normal brain tissues. High protein level of SCAMP3 was correlated with larger tumor size and advanced WHO grade. Glioma patients with high-SCAMP3 level had worse overall survival. In addition, SCAMP3 was defined as an independent risk factor of glioma prognosis. Cellular and xenograft studies revealed that SCAMP3 promotes glioma proliferation possibly through enhancing EGFR and mTORC1 signaling.

Discussion

Our studies revealed that high-SCAMP3 expression level was closely related to the unfavorable clinical features and poor prognosis of glioma patients. SCAMP3 may serve as an invaluable prognostic indicator and novel therapeutic target for glioma treatment.

Expression profiling revealed keratins and interleukins as potential biomarkers in squamous cell carcinoma of horn in Indian bullocks (Bos indicus)

Horn cancer is most prevalent in Bos indicus and poorly defined genetic landscape makes disease diagnosis and treatment difficult. In this study, RNA-Seq and data analysis using CLC Genomics Workbench was employed to identify biomarkers associated with horn cancer. As a result, a total of 149 genes were found significant differentially expressed in horn cancer samples compared to horn normal samples. The study revealed 'keratins' and 'interleukins' as apex groups of significant differentially expressed genes (DEGs). Functional analysis showed that the upregulated keratins support metastasis of tumor via cell proliferation, migration, and affecting cell stability, while downregulated interleukins along with other associated chemokine receptors deprive the immune response to tumor posing clear path for metastasis of horn cancer. Combi-action of both the group facilitates the tumor microenvironment to reproduce tumorigenesis. Analysis of pathways enriched in DEGs and exemplified protein-protein interaction network indicated actual role of DEGs in horn cancer at a fine level. Important effect of deregulated expression of keratin and interleukin genes in horn cancer enrolling their candidacy as potential biomarkers for horn cancer prognosis. This study appraises the possibility to mitigate horn cancer at fine resolution to extract attainable identification of prognostic molecular portraits.

Metastasis suppressor 1 acts as a tumor suppressor by inhibiting epithelial-to-mesenchymal transition in triple-negative breast cancer

OBJECTIVE

This study aimed to analyze the function of metastasis suppressor 1 (MTSS1) in triple negative breast cancer (TNBC).

METHODS

MTSS1 expression in 30 TNBC and paracancerous tissues was measured by quantitative reverse transcriptase polymerase chain reaction. The prognostic value of MTSS1 was assessed by Kaplan-Meier analysis followed by the log-rank test. MCF7 cells were transfected with si-MTSS1, while MDA-MB-231 cells were transfected with pcDNA3.1-MTSS1. Cell proliferation assay and transwell assay were performed to investigate the effects of MTSS1 on the biological behavior of breast cancer cells. Immunofluorescence and western blot were used to detect the influence of MTSS1 on epithelial-mesenchymal transition (EMT) markers.

RESULTS

MTSS1 expression was significantly lower in TNBC tissues compared with that in paracancerous tissues (0.012 vs. 0.370; P = 0.006). A lower MTSS1 expression level was also found in tumor tissues of patients with lymph node metastasis (P = 0.002) or tumor node metastasis stage (P = 0.010). Patients with low expression of MTSS1 (⩽ 0.009) had shorter disease-free survival (47.4 vs. 56.0 months; P = 0.012). The knockdown of MTSS1 in MCF7 cells inhibited cell proliferation, enhanced cell migration and invasion capacities, decreased the E-cadherin level, and increased the vimentin level, whereas overexpression of MTSS1 in MDA-MB-231 cells had the opposite effects (P < 0.05).

CONCLUSIONS

Our findings demonstrated that MTSS1 regulates proliferation, invasion, migration, and EMT in TNBC, and that decreased MTSS1 is associated with shorter disease-free survival.

MTSS1 suppresses mammary tumor-initiating cells by enhancing RBCK1-mediated p65 ubiquitination

Tumor-initiating cells (TICs) are considered the culprits of cancer development and progression. Dysregulation of metastasis suppressor protein 1 (MTSS1) has been widely observed in tumor metastasis, but its functional contribution and mechanism in cancer is poorly understood. Here we report a role of MTSS1 in suppressing TICs in breast cancer. Mtss1 knockout (KO) enhances the mammary epithelial TIC subpopulation in both luminal and basal-like breast cancer mouse models. MTSS1 also suppresses tumorsphere formation in breast cancer cells. Mechanistically, MTSS1 interacts with the E3 ligase RanBP2-type and C3HC4-type zinc finger containing 1 (RBCK1) to facilitate RBCK1-mediated p65 ubiquitination and degradation, thus suppressing the NF-κB signaling pathway and tumorigenesis. In addition, actin beta-like 2 (ACTBL2) competes with RBCK1 for MTSS1 binding, leading to p65 stabilization. Importantly, MTSS1 silencing promotes patient-derived organoid formation and xenograft growth. MTSS1 downregulation in clinical tumors is also linked to worse prognosis. Overall our data reveal a new paradigm of NF-κB regulation and may have important implications in therapeutics targeting TICs.

Prognostic role of SCAMP family in acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant disease of myeloid hematopoietic stem or progenitor cells characterized by abnormal proliferation of primary and immature myeloid cells in bone marrow and peripheral blood. Gene mutation and expression profiles can be used as prognosis predictors for different prognostic subgroups. Secretory carrier-associated membrane proteins (SCAMPs) are a multigenic family with five members and act as cell surface vectors in the post-Golgi recycling pathways in mammals. Nevertheless, the prognostic and clinical influence of SCAMP family has hardly ever been illustrated in AML. In our study, expression patterns of SCAMP family (SCAMP1-5) were analyzed in 155 AML patients which were extracted from the Cancer Genome Atlas database. In chemotherapy, only subgroup, higher SCAMP1 level was significantly associated with longer EFS and OS (all P = 0.002), and SCAMP1 was confirmed to be an independent favorable factor in un-transplanted patients by Multivariate analysis (all P < 0.05). Nevertheless, in the allogeneic hematopoietic stem cell transplantation (allo-HSCT) treatment subgroup, none of the SCAMP genes had any effect on the clinical survival. Our study found that high expression level of SCAMP1 is a favorable prognostic factor in AML, but allo-HSCT may neutralize its prognostic effect.

UBE2O promotes the proliferation, EMT and stemness properties of breast cancer cells through the UBE2O/AMPKα2/mTORC1-MYC positive feedback loop

Ubiquitin-conjugating enzyme E2O (UBE2O) is a large E2 ubiquitin-conjugating enzyme that possesses both E2 and E3 ligase activities. Ectopic UBE2O overexpression is associated with a variety of human diseases, especially cancers. However, the expression profile and functional biology of UBE2O in human breast cancer (BC) remain unclear. In this study, we found that UBE2O was significantly overexpressed in human BC tissues and cells. Patients with high UBE2O expression tended to have a high risk of metastasis and poor prognosis. In vitro assays revealed that UBE2O promoted BC cell proliferation and epithelial-mesenchymal transformation (EMT) and endowed BC cells with cancer stemness properties (CSPs). UBE2O knockdown in MDA-MB-231 cells suppressed tumour growth and lung metastasis in MDA-MB-231 xenograft mouse models. Mechanistically, UBE2O functioned as a ubiquitin enzyme of AMPKα2, promoting its ubiquitination and degradation and thus activating the mTORC1 signal pathway and contributing to BC oncogenesis and metastasis. Furthermore, as a downstream factor of the UBE2O/AMPKα2/mTORC1 axis, the oncoprotein MYC transcriptionally promoted UBE2O and formed a positive feedback loop in human BC. Collectively, our study demonstrated that UBE2O/AMPKα2/mTORC1-MYC forms a positive feedback loop in human BC cells that regulates BC cell proliferation and EMT and endows BC cells with CSPs.

Transcriptomic analysis to affirm the regulatory role of long non-coding RNA in horn cancer of Indian zebu cattle breed Kankrej (Bos indicus)

Long non-coding RNA (lncRNA) was previously considered as a non-functional transcript, which now established as part of regulatory elements of biological events such as chromosome structure, remodeling, and regulation of gene expression. The study presented here showed the role of lncRNA through differential expression analysis on cancer-related coding genes in horn squamous cell carcinoma of Indian zebu cattle. A total of 10,360 candidate lncRNAs were identified and further analyzed for its coding potential ability using three tools (CPC, CPAT, and PLEK) that provide 8862 common lncRNAs. Pfam analysis of these common lncRNAs gave 8612 potential candidates for lncRNA differential expression analysis. Differential expression analysis showed a total of 59 significantly differentially expressed genes and 19 lncRNAs. Pearson's correlation analysis was used to identify co-expressed mRNA-lncRNAs to established relation of the regulatory role of lncRNAs in horn cancer. We established a positive relation of seven upregulated (XLOC_000016, XLOC_002198, XLOC_002851, XLOC_ 007383, XLOC_010701, XLOC_010272, and XLOC_011517) and one downregulated (XLOC_011302) lncRNAs with eleven genes that are related to keratin family protein, keratin-associated protein family, cornifelin, corneodesmosin, serpin family protein, and metallothionein that have well-established role in squamous cell carcinoma through cellular communication, cell growth, cell invasion, and cell migration. These biological events were found to be related to the MAPK pathway of cell cycle regulation indicating the role of lncRNAs in manipulating cell cycle regulation during horn squamous cell carcinomas that will be useful in identifying molecular portraits related to the development of horn cancer.

Knockdown of LncRNA SCAMP1 suppressed malignant biological behaviours of glioma cells via modulating miR-499a-5p/LMX1A/NLRC5 pathway

Dysregulation of long non‐coding RNAs (lncRNAs) confirm that it plays a crucial role in tumourigenesis and malignant progression of glioma. The present study demonstrated that LncRNA secretory carrier membrane protein 1 (SCAMP1) was up‐regulated and functioned as an oncogene in glioma cells. In addition, miR‐499a‐5p was down‐regulated meanwhile exerted tumour‐suppressive function in glioma cells. Subsequently, inhibition of SCAMP1 significantly restrained the cell proliferation, migration and invasion, as well as promoted apoptosis by acting as a molecular sponge of miR‐499a‐5p. Transcription factor LIM homeobox transcription factor 1, alpha (LMX1A) was overexpressed in glioma tissues and cells. Moreover, miR‐499a‐5p targeted LMX1A 3′‐UTR in a sequence‐specific manner. Hence, down‐regulation of SCAMP1 remarkably reduced the expression level of LMX1A, indicating that LMX1A participated in miR‐499a‐5p‐induced tumour‐suppressive effects on glioma cells. Furthermore, knockdown of LMX1A decreased NLR family, CARD domain containing 5 (NLRC5) mRNA and protein expression levels through directly binding to the NLRC5 promoter region. Down‐regulation of NLRC5 obviously inhibited malignant biological behaviours of glioma cells through attenuating the activity of Wnt/β‐catenin signalling pathway. In conclusion, our study clarifies that SCAMP1/miR‐499a‐5p/LMX1A/NLRC5 axis plays a critical role in modulating malignant progression of glioma cells, which provide a novel therapeutic strategy for glioma treatment.

PYK2 promotes HER2-positive breast cancer invasion

BACKGROUND

Metformin, a biguanide, is one of the most commonly prescribed treatments for type 2 diabetes and has recently been recommended as a potential drug candidate for advanced cancer therapy. Although Metformin has antiproliferative and proapoptotic effects on breast cancer, the heterogenous nature of this disease affects the response to metformin leading to the activation of pro-invasive signalling pathways that are mediated by the focal adhesion kinase PYK2 in pure HER2 phenotype breast cancer.

METHODS

The effect of metformin on different breast cancer cell lines, representing the molecular heterogenicity of the disease was investigated using in vitro proliferation and apoptosis assays. The activation of PYK2 by metformin in pure HER2 phenotype (HER2+/ER-/PR-) cell lines was investigated by microarrays, quantitative real time PCR and immunoblotting. Cell migration and invasion PYK2-mediated and in response to metformin were determined by wound healing and invasion assays using HER2+/ER-/PR- PYK2 knockdown cell lines. Proteomic analyses were used to determine the role of PYK2 in HER2+/ER-/PR- proliferative, migratory and invasive cellular pathways and in response to metformin. The association between PYK2 expression and HER2+/ER-/PR- patients' cancer-specific survival was investigated using bioinformatic analysis of PYK2 expression from patient gene expression profiles generated by the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) study. The effect of PYK2 and metformin on tumour initiation and invasion of HER2+/ER-/PR- breast cancer stem-like cells was performed using the in vitro stem cell proliferation and invasion assays.

RESULTS

Our study showed for the first time that pure HER2 breast cancer cells are more resistant to metformin treatment when compared with the other breast cancer phenotypes. This drug resistance was associated with the activation of PTK2B/PYK2, a well-known mediator of signalling pathways involved in cell proliferation, migration and invasion. The role of PYK2 in promoting invasion of metformin resistant HER2 breast cancer cells was confirmed through investigating the effect of PYK2 knockdown and metformin on cell invasion and by proteomic analysis of associated cellular pathways. We also reveal a correlation between high level of expression of PYK2 and reduced survival in pure HER2 breast cancer patients. Moreover, we also report a role of PYK2 in tumour initiation and invasion-mediated by pure HER2 breast cancer stem-like cells. This was further confirmed by demonstrating a correlation between reduced survival in pure HER2 breast cancer patients and expression of PYK2 and the stem cell marker CD44.

CONCLUSIONS

We provide evidence of a PYK2-driven pro-invasive potential of metformin in pure HER2 cancer therapy and propose that metformin-based therapy should consider the molecular heterogeneity of breast cancer to prevent complications associated with cancer chemoresistance, invasion and recurrence in treated patients.

Chlorotoxin targets ERα/VASP signaling pathway to combat breast cancer

Breast cancer is one of the most common malignant tumors among women worldwide. About 70‐75% of primary breast cancers belong to estrogen receptor (ER)‐positive breast cancer. In the development of ER‐positive breast cancer, abnormal activation of the ERα pathway plays an important role and is also a key point leading to the failure of clinical endocrine therapy. In this study, we found that the small molecule peptide chlorotoxin (CTX) can significantly inhibit the proliferation, migration and invasion of breast cancer cells. In in vitro study, CTX inhibits the expression of ERα in breast cancer cells. Further studies showed that CTX can directly bind to ERα and change the protein secondary structure of its LBD domain, thereby inhibiting the ERα signaling pathway. In addition, we also found that vasodilator stimulated phosphoprotein (VASP) is a target gene of ERα signaling pathway, and CTX can inhibit breast cancer cell proliferation, migration, and invasion through ERα/VASP signaling pathway. In in vivo study, CTX significantly inhibits growth of ER overexpressing breast tumor and, more importantly, based on the mechanism of CTX interacting with ERα, we found that CTX can target ER overexpressing breast tumors in vivo. Our study reveals a new mechanism of CTX anti‐ER‐positive breast cancer, which also provides an important reference for the study of CTX anti‐ER‐related tumors.

Metastasis suppressor protein 1 regulated by PTEN suppresses invasion, migration, and EMT of gastric carcinoma by inactivating PI3K/AKT signaling

Epithelial-mesenchymal transition (EMT) is a crucial event for cancer progression and metastasis. Metastasis suppressor protein 1 (MTSS1) is a metastasis suppressor in several cancers. In this study, we elucidated the potential physiological function of MTSS1 in the invasion and migration of gastric cancer (GC), and its distinct role in EMT and subsequently determined the potential molecular mechanism. We observed that MTSS1 expression was downregulated in GC tissues and several GC cell lines (SGC-7901, MGC-803, MKN-28, MKN-45, and BGC-823). Importantly, forced expression of MTSS1 drastically diminished the cell viability in both SGC-7901 and MKN-45 cells. Moreover, overexpression of MTSS1 attenuated the invasion ability of these two cell lines. In addition to the invasive capability, introduction of MTSS1 led to a loss of migratory potential. Furthermore, augmentation of MTSS1 exhibited the typical EMT phenotype switch, accompanied by enhanced the expression of vimentin and N-cadherin and reduced E-cadherin expression. Interestingly, MTSS1 also repressed transforming growth factor beta 1 (TGF-β1)-induced EMT. Our mechanistic investigations revealed that MTSS1 was positively regulated by the phosphatase and tensin homolog (PTEN), and it functioned as a tumor suppressor, possibly by inactivating the phosphoinositide 3-kinase (PI3K)/v-akt murine thymoma viral oncogene (AKT) pathway in GC cells. Collectively, our data provide insight into an important role for MTSS1 in suppressing tumor cell invasion, migration and EMT, which indicates that MTSS1 may act as a prospective prognostic biological marker and a promising therapeutic target for GC.