Overexpression of SASH1 related to the decreased invasion ability of human glioma U251 cells

Deciphering novel mitochondrial signatures: multi-omics analysis uncovers cross-disease markers and oligodendrocyte pathways in Alzheimer's disease and glioblastoma

Introduction

Alzheimer's disease (AD) and glioblastoma (GBM) are severe neurological disorders that pose significant global healthcare challenges. Despite extensive research, the molecular mechanisms, particularly those involving mitochondrial dysfunction, remain poorly understood. A major limitation in current studies is the lack of cell-specific markers that effectively represent mitochondrial dynamics in AD and GBM.

Methods

In this study, we analyzed single-cell transcriptomic data using 10 machine learning algorithms to identify mitochondria-associated cell-specific markers. We validated these markers through the integration of gene expression and methylation data across diverse cell types. Our dataset comprised single-nucleus RNA sequencing (snRNA-seq) from AD patients, single-cell RNA sequencing (scRNA-seq) from GBM patients, and additional DNA methylation and transcriptomic data from the ROSMAP, ADNI, TCGA, and CGGA cohorts.

Results

Our analysis identified four significant cross-disease mitochondrial markers: EFHD1, SASH1, FAM110B, and SLC25A18. These markers showed both shared and unique expression profiles in AD and GBM, suggesting a common mitochondrial mechanism contributing to both diseases. Additionally, oligodendrocytes and their interactions with astrocytes were implicated in disease progression, particularly through the APP signaling pathway. Key hub genes, such as HS6ST3 and TUBB2B, were identified across different cellular subpopulations, highlighting a cell-specific co-expression network linked to mitochondrial function.

SASH1: A Novel Eph Receptor Partner and Insights into SAM-SAM Interactions

The Eph (erythropoietin-producing human hepatocellular) receptor family, the largest subclass of receptor tyrosine kinases (RTKs), plays essential roles in embryonic development and neurogenesis. The intracellular Sterile Alpha Motif (SAM) domain presents a critical structural feature that distinguishes Eph receptors from other RTKs and participates in recruiting and binding downstream molecules. This study identified SASH1 (SAM and SH3 domain containing 1) as a novel Eph receptor-binding partner through SAM-SAM domain interactions. Our comprehensive biochemical analyses revealed that SASH1 selectively interacts with Eph receptors via its SAM1 domain, displaying the highest affinity for EphA8. The high-resolution crystal structure of the EphA8-SASH1 complex provided insights into the specific intermolecular interactions between these proteins. Cellular assays confirmed that EphA8 and SASH1 co-localize and co-precipitate in mammalian cells, with cancer mutations (EphA8 R942H or G978D) impairing this interaction. We demonstrated that SAM-SAM interaction is critical for SASH1-mediated regulation of EphA8 kinase activity, shedding new light on the Eph signaling pathway and expanding our understanding of the molecular basis of the tumor suppressor gene SASH1.

The Structural Dynamics, Complexity of Interactions, and Functions in Cancer of Multi-SAM Containing Proteins

SAM domains are crucial mediators of diverse interactions, including those important for tumorigenesis or metastasis of cancers, and thus SAM domains can be attractive targets for developing cancer therapies. This review aims to explore the literature, especially on the recent findings of the structural dynamics, regulation, and functions of SAM domains in proteins containing more than one SAM (multi-SAM containing proteins, MSCPs). The topics here include how intrinsic disorder of some SAMs and an additional SAM domain in MSCPs increase the complexity of their interactions and oligomerization arrangements. Many similarities exist among these MSCPs, including their effects on cancer cell adhesion, migration, and metastasis. In addition, they are all involved in some types of receptor-mediated signaling and neurology-related functions or diseases, although the specific receptors and functions vary. This review also provides a simple outline of methods for studying protein domains, which may help non-structural biologists to reach out and build new collaborations to study their favorite protein domains/regions. Overall, this review aims to provide representative examples of various scenarios that may provide clues to better understand the roles of SAM domains and MSCPs in cancer in general.

Pan-Cancer Integrated Analysis Identification of SASH3, a Potential Biomarker That Inhibits Lung Adenocarcinoma Progression

Sterile alpha motif (SAM) and Src homology-3 (SH3) domain-containing 3 (SASH3) is an adaptor protein expressed mainly in lymphocytes, and plays significant roles in T-cell proliferation and cell survival. However, its expression level, clinical significance, and correlation with tumor-infiltrating immune cells across cancers remain unclear. In this study, we comprehensively examined the expression, dysregulation, and prognostic significance of SASH3, and the correlation with clinicopathological parameters and immune infiltration in pan-cancer. The mRNA and protein expression status of SASH3 were determined by TCGA, GTEx, and UALCAN. Kaplan–Meier analysis utilized the prognostic values of SASH3 in diverse cancers. The association between SASH3 expression and gene mutation, DNA methylation, immune cells infiltration, immune checkpoints, tumor mutation burden (TMB), and microsatellite instability (MSI) were analyzed using data from the TCGA database. High expression of SASH3 was not only linked to poor OS in ESCC, LAML, LGG, and UVM, but also associated with better OS in CESC, HNSC, LUAD, SARC, SKCM, THYM, and UCEC. As for DSS, a high level of SASH3 correlated with adverse DSS in ESCC, LGG, and UVM, and lowly expressed SASH3 was associated with shorter OS in CESC, HNSC, LUAD, SARC, SKCM, and UCEC. The results of Cox regression and nomogram analyses confirmed that SASH3 was an independent factor for LUAD prognosis. Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) results showed that SASH3 was involved in natural killer cell-mediated cytotoxicity, Th17 cell differentiation, PD-L1 expression and PD-1 checkpoint pathway in cancer, NF-kappa B signaling pathway, B-cell receptor signaling pathway, and Toll-like receptor signaling pathway. SASH3 expression was correlated with TMB in 28 cancer types and associated with MSI in 22 cancer types, while there was a negative correlation between SASH3 expression and DNA methylation in diverse human cancer. The high DNA methylation level of SASH3 was correlated with better OS in KIRC and UVM, and associated with poor OS in SKCM. Moreover, we uncover that SASH3 expression was positively associated with the stroma score in 27 cancer types, the microenvironment score, and immune score in 32 cancer types, 38 types of immune cells in 32 cancer types, the 45 immune stimulators, 24 immune inhibitors, 41 chemokines, 18 receptors, and 21 major histocompatibility complex (MHC) molecules in 33 cancer types. Finally, forced SASH3 expression inhibited lung adenocarcinoma (LUAD) cell proliferation and cell migration. Our findings confirmed that SASH3 may be a biomarker for the prognosis and diagnosis of human cancer.

The emerging and diverse roles of the SLy/SASH1-protein family in health and disease-Overview of three multifunctional proteins

Intracellular adaptor proteins are indispensable for the transduction of receptor-derived signals, as they recruit and connect essential downstream effectors. The SLy/SASH1-adaptor family comprises three highly homologous proteins, all of them sharing conserved structural motifs. The initial characterization of the first member SLy1/SASH3 (SH3 protein expressed in lymphocytes 1) in 2001 was rapidly followed by identification of SLy2/HACS1 (hematopoietic adaptor containing SH3 and SAM domains 1) and SASH1/SLy3 (SAM and SH3 domain containing 1). Based on their pronounced sequence similarity, they were subsequently classified as one family of intracellular scaffold proteins. Despite their obvious homology, the three SLy/SASH1-members fundamentally differ with regard to their expression and function in intracellular signaling. On the contrary, growing evidence clearly demonstrates an important role of all three proteins in human health and disease. In this review, we systematically summarize what is known about the SLy/SASH1-adaptors in the field of molecular cell biology and immunology. To this end, we recapitulate current research about SLy1/SASH3, SLy2/HACS1, and SASH1/SLy3, with an emphasis on their similarities and differences.

SASH1 is a prognostic indicator and potential therapeutic target in non-small cell lung cancer

SASH1 (SAM and SH3 domain-containing protein 1) is a tumor suppressor protein that has roles in key cellular processes including apoptosis and cellular proliferation. As these cellular processes are frequently disrupted in human tumours and little is known about the role of SASH1 in the pathogenesis of the disease, we analysed the prognostic value of SASH1 in non-small cell lung cancers using publicly available datasets. Here, we show that low SASH1 mRNA expression is associated with poor survival in adenocarcinoma. Supporting this, modulation of SASH1 levels in a panel of lung cancer cell lines mediated changes in cellular proliferation and sensitivity to cisplatin. The treatment of lung cancer cells with chloropyramine, a compound that increases SASH1 protein concentrations, reduced cellular proliferation and increased sensitivity to cisplatin in a SASH1-dependent manner. In summary, compounds that increase SASH1 protein levels could represent a novel approach to treat NSCLC and warrant further study.

Expression of SASH1 in Preeclampsia and Its Effects on Human Trophoblast

Aim

To explore the involvement of SASH1 in preeclampsia.

Methods

Expression of SASH1 was determined by qPCR, WB, and immunohistochemistry in the placenta of both normal and preeclamptic pregnancies. The SASH1 gene of human HTR-8/SVneo cells was overexpressed by transfection of pEZ-Lv206-SASH1. After that, the CCK-8 assay, EdU assay, transwell assay, and flow cytometry were used to examine the cell proliferation, migration, invasion, and apoptosis.

Results

Higher expression of SASH1 was detected in placental tissues collected from patients with preeclampsia, compared with those from gestational age-matched control samples. The expression of SASH1 was significantly enhanced by transfection with pEZ-Lv206-SASH1 in HTR-8/SVneo cells. In addition, the HTR-8/SVneo cells transfected with pEZ-Lv206-SASH1 exhibited significantly reduced proliferation, migration, and invasion ability compared to the cells in the empty vector group and normal group. Flow cytometry analysis demonstrated that the apoptosis rate of cells transfected with pEZ-Lv206-SASH1 was significantly higher than that of cells transfected with empty vector and untreated cells.

Conclusions

SASH1 is significantly upregulated in the placenta of preeclampsia, and overexpression of SASH1 can inhibit the proliferation, migration, and invasion, but induce apoptosis of trophoblast cells in vitro.

Role of exosomes in malignant glioma: microRNAs and proteins in pathogenesis and diagnosis

Malignant gliomas are the most common and deadly type of central nervous system tumors. Despite some advances in treatment, the mean survival time remains only about 1.25 years. Even after surgery, radiotherapy and chemotherapy, gliomas still have a poor prognosis. Exosomes are the most common type of extracellular vesicles with a size range of 30 to 100 nm, and can act as carriers of proteins, RNAs, and other bioactive molecules. Exosomes play a key role in tumorigenesis and resistance to chemotherapy or radiation. Recent evidence has shown that exosomal microRNAs (miRNAs) can be detected in the extracellular microenvironment, and can also be transferred from cell to cell via exosome secretion and uptake. Therefore, many recent studies have focused on exosomal miRNAs as important cellular regulators in various physiological and pathological conditions. A variety of exosomal miRNAs have been implicated in the initiation and progression of gliomas, by activating and/or inhibiting different signaling pathways. Exosomal miRNAs could be used as therapeutic agents to modulate different biological processes in gliomas. Exosomal miRNAs derived from mesenchymal stem cells could also be used for glioma treatment. The present review summarizes the exosomal miRNAs that have been implicated in the pathogenesis, diagnosis and treatment of gliomas. Moreover, exosomal proteins could also be involved in glioma pathogenesis. Exosomal miRNAs and proteins could also serve as non-invasive biomarkers for prognosis and disease monitoring. Video Abstract.

Silencing SCAMP1-TV2 Inhibited the Malignant Biological Behaviors of Breast Cancer Cells by Interaction With PUM2 to Facilitate INSM1 mRNA Degradation

Background: Molecular-targeted therapy plays an important role in the combined treatment of breast cancer. Long noncoding RNA (LncRNA) plays a significant role in regulating breast cancer progression. The present study is to reveal the potential roles and molecular mechanism that the secretory carrier-associated membrane protein 1-transcript variant 2 (SCAMP1-TV2) has in breast.

Methods: Cell Counting Kit-8 (CCK-8), RNA Immunoprecipitation (RIP), and RNA pull-down assays were employed to determine the interactions between SCAMP1-TV2 and Pumilio RNA binding family member 2 (PUM2). The luciferase reporter assays and chromatin immunoprecipitation (ChIP) assays were used to get to know the effect of human insulinoma-associated 1 (INSM1) directly on the SAM and SH3 domain containing 1 (SASH1) promoter.

Results: Silenced SCAMP1-TV2 inhibited the proliferation, migration, and invasion of breast cancer cells, and promoted cell apoptosis. Meanwhile, SCAMP1-TV2 downregulation decreased its binding to PUM2 and increased the binding of PUM2 to INSM1 messenger RNA (mRNA), thus promoting the degradation of INSM1 mRNA. Silencing INSM1 decreased its inhibitory effect on SASH1 transcription and inhibited the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway. The xenograft tumor growth in a nude mice was significantly inhibited by the silencing of SCAMP1-TV2 in combination with the overexpression of PUM2.

Conclusions: SCAMP1-TV2/PUM2/INSM1 pathway plays an important role in regulating the biological behavior of breast cancer cells.

SASH1 promotes melanin synthesis and migration via suppression of TGF-β1 secretion in melanocytes resulting in pathologic hyperpigmentation

Dyschromatosis universalis hereditaria (DUH) is an autosomal dominant pigmentary genodermatosis characterized by the presence of patches of hyperpigmentation and hypopigmented macules distributed over the body, with most cases reported in Asia. DUH is a heterogeneous disease and a small portion of patients carry the ABCB6 variant. In the present study, exome sequencing of four generations of a Chinese family with DUH identified a c.1761C>G (p.Ser587Arg) mutation in exon 15 of SAM and SH3 domain containing 1 (SASH1) that was found to co-segregate in some family members. Immunohistological analysis of biopsy specimens showed that SASH1 was diffusely distributed in all layers of the epidermis, suggesting increased transepithelial migration of melanocytes (MCs). The point mutation c.1761C>G of SASH1 was successfully induced in immortalized human melanocyte (PIG1) cells, which resulted in the downregulation of SASH1 expression. Bioinformatics analysis showed that mutated SASH1 downregulated thrombospondin 1 (THBS1) expression and inactivated transforming growth factor beta 1 (TGF-β1) signaling. TGF-β1 expression by PIG1cells was found to negatively regulate SASH1 protein expression. Transwell migration and wound-healing assays showed an increase in the migration and invasion capabilities of the cells carrying the mutation. Further, SASH1 mutations induced downregulation of melanin content. The study results suggest cross-talking between SASH1-TGF-β1 signaling, demonstrating the proposed MC migration modulation models and affecting melanin trafficking in the epithelium.

HMGB1 contributes to SASH1 methylation to attenuate astrocyte adhesion

SAM and SH3 domain-containing 1 (SASH1), a scaffold protein, is regarded as a tumor suppressor. Recent studies have verified the decreased expression of SASH1 in many tumors. Our previous clinical investigation found that SASH1 was widely expressed in normal brain tissues but reduced or absent in glioma tissues. However, the functions of SASH1 in normal astrocytes and the reasons for the reductions in SASH1 levels in glioma tissues are unclear. In this study, we found that in astrocytes, SASH1 functions in cell adhesion. We observed that knockdown of SASH1 expression in cultured astrocytes significantly decreased cell adhesion and increased invasion. Conversely, overexpression of SASH1 in C6 cells markedly promoted cell adhesion and decreased cell invasion. In addition, we found that the expression level of one member of the integrin family, integrin β8, was significantly reduced in SASH1-downregulated astrocytes and elevated in SASH1-upregulated C6 cells. Furthermore, the results of methylation and ChIP assays showed that the methylation level of the SASH1 gene was markedly higher in C6 cells than in astrocytes and that HMGB1 could bind to the CpG islands of the SASH1 gene. HMGB1 overexpression in astrocytes significantly increased the methylation level of the SASH1 gene. This study reveals, for the first time, that HMGB1 contributes to the methylation of the SASH1 gene, and our findings suggest that methylation downregulates the expression of the SASH1 gene and later reduces integrin β8 expression, thereby reducing cell adhesion and promoting cell migration.

Diapause in a tropical oil-collecting bee: molecular basis unveiled by RNA-Seq

BACKGROUND

Diapause is a natural phenomenon characterized by an arrest in development that ensures the survival of organisms under extreme environmental conditions. The process has been well documented in arthropods. However, its molecular basis has been mainly studied in species from temperate zones, leaving a knowledge gap of this phenomenon in tropical species. In the present study, the Neotropical and solitary bee Tetrapedia diversipes was employed as a model for investigating diapause in species from tropical zones. Being a bivoltine insect, Tetrapedia diversipes produce two generations of offspring per year. The first generation, normally born during the wet season, develops faster than individuals from the second generation, born after the dry season. Furthermore, it has been shown that the development of the progeny, of the second generation, is halted at the 5th larval instar, and remains in larval diapause during the dry season. Towards the goal of gaining a better understanding of the diapause phenomenon we compared the global gene expression pattern, in larvae, from both reproductive generations and during diapause. The results demonstrate that there are similarities in the observed gene expression patterns to those already described for temperate climate models, and also identify diapause-related genes that have not been previously reported in the literature.

RESULTS

The RNA-Seq analysis identified 2275 differentially expressed transcripts, of which 1167 were annotated. Of these genes, during diapause, 352 were upregulated and 815 were downregulated. According to their biological functions, these genes were categorized into the following groups: cellular detoxification, cytoskeleton, cuticle, sterol and lipid metabolism, cell cycle, heat shock proteins, immune response, circadian clock, and epigenetic control.

CONCLUSION

Many of the identified genes have already been described as being related to diapause; however, new genes were discovered, for the first time, in this study. Among those, we highlight: Niemann-Pick type C1, NPC2 and Acyl-CoA binding protein homolog (all involved in ecdysteroid synthesis); RhoBTB2 and SASH1 (associated with cell cycle regulation) and Histone acetyltransferase KAT7 (related to epigenetic transcriptional regulation). The results presented here add important findings to the understanding of diapause in tropical species, thus increasing the comprehension of diapause-related molecular mechanisms.

Overexpression of SASH1 Inhibits TGF-β1-Induced EMT in Gastric Cancer Cells

The epithelial–mesenchymal transition (EMT) is considered to be one of the critical steps in gastric cancer cell invasion and metastasis. SAM- and SH3-domain containing 1 (SASH1), a member of the SLY family of signal adapter proteins, is a candidate for tumor suppression in several cancers. However, the biological role of SASH1 in gastric cancer remains largely unknown. Therefore, the purpose of this study was to investigate the impact of SASH1 on the biological behavior of gastric cancer cells treated with transforming growth factor (TGF)-β1. In the current study, we provide evidence that SASH1 was lowly expressed in human gastric cancer cells, and TGF-β1 also inhibited the expression of SASH1 in TSGH cells. We found that SASH1 inhibited TGF-β1-mediated EMT in TSGH cells, as well as cell migration and invasion. Furthermore, SASH1 obviously inhibited the phosphorylation of PI3K and Akt in TGF-β1-stimulated TSGH cells. In summary, our study is the first to show that overexpression of SASH1 inhibits TGF-β1-induced EMT in gastric cancer cells through the PI3K/Akt signaling pathway. These results suggest that SASH1 may be a potential therapeutic target for the treatment of gastric cancer.

Overexpression of SASH1 Inhibits the Proliferation, Invasion, and EMT in Hepatocarcinoma Cells

The SASH1 (SAM- and SH3-domain containing 1) gene, a member of the SLY (SH3 domain containing expressed in lymphocytes) family of signal adapter proteins, has been implicated in tumorigenesis of many types of cancers. However, the role and mechanism of SASH1 in the invasion and metastasis of hepatocarcinoma are largely unknown. In this study, we investigated the role and mechanism of SASH1 in the invasion and metastasis of hepatocarcinoma. Our results showed that SASH1 was lowly expressed in hepatocarcinoma cell lines. The in vitro experiments showed that overexpression of SASH1 inhibited the proliferation and migration/invasion of hepatocarcinoma cells, as well as the epithelial-mesenchymal transition (EMT) progress. Furthermore, overexpression of SASH1 suppressed the expression of Shh as well as Smo, Ptc, and Gli-1 in hepatocarcinoma cells. Taken together, these results suggest that overexpression of SASH1 inhibited the proliferation and invasion of hepatocarcinoma cells through the inactivation of Shh signaling pathway. Therefore, these findings reveal that SASH1 may be a potential therapeutic target for the treatment of hepatocarcinoma.

Correlation of SASH1 expression and ultrasonographic features in breast cancer

Objective

SASH1 is a member of the SH3/SAM adapter molecules family and has been identified as a new tumor suppressor and critical protein in signal transduction. An ectopic expression of SASH1 is associated with decreased cell viability of breast cancer. The aim of this study was to explore the association between SASH1 expression and the ultrasonographic features in breast cancer.

Patients and methods

A total of 186 patients diagnosed with breast cancer were included in this study. The patients received preoperative ultrasound examination, and the expression of SASH1 was determined using immunohistochemistry methods. Spearman’s rank correlation analysis was used to analyze the correlation between SASH1-positive expression and the ultrasonographic features.

Results

The positive expression of SASH1 was observed in 63 (33.9%) patients. The positive expression rate of SASH1 was significantly decreased in patients with breast cancer (63/186, 33.9%) compared with controls (P<0.001). The positive expression rate of SASH1 was significantly decreased in patients with edge burr sign (P=0.025), lymph node metastasis (P=0.007), and a blood flow grade of III (P=0.013) compared with patients without those adverse ultrasonographic features. The expression of SASH1 was negatively correlated with edge burr sign (P=0.025), lymph node metastasis (P=0.007), and blood flow grade (P=0.003) of the patients with breast cancer.

Conclusion

The expression of SASH1 was inversely correlated with some critical ultrasonographic features, including edge burr sign, lymph node metastasis, and blood flow grade in breast cancer, and decreased SASH1 expression appears to be associated with adverse clinical and imaging features in breast cancer.

Synthetic Isoliquiritigenin Inhibits Human Tongue Squamous Carcinoma Cells through Its Antioxidant Mechanism

Isoliquiritigenin (ISL), a natural antioxidant, has antitumor activity in different types of cancer cells. However the antitumor effect of ISL on human tongue squamous carcinoma cells (TSCC) is not clear. Here we aimed to investigate the effects of synthetic isoliquiritigenin (S-ISL) on TSCC and elucidate the underlying mechanisms. S-ISL was synthesized and elucidated from its nuclear magnetic resonance spectrum and examined using high performance liquid chromatography. The effects of S-ISL on TSCC cells (Tca8113) were evaluated in relation to cell proliferation, apoptosis and adhesion, migration, and invasion using sulforhodamine B assay, fluorescence microscopy technique, flow cytometry (FCM) analysis, and Boyden chamber assay. The associated regulatory mechanisms were examined using FCM and fluorescence microscopy for intracellular reactive oxygen species (ROS) generation, Gelatin zymography assay for matrix metalloproteinase (MMP) activities, and Western blot for apoptosis regulatory proteins (Bcl-2 and Bax). Our data indicated that S-ISL inhibited Tca8113 cell proliferation, adhesion, migration, and invasion while promoting the cell apoptosis. Such effects were accompanied by downregulation of Bcl-2 and upregulation of Bax, reduction of MMP-2 and MMP-9 activities, and decreased ROS production. We conclude that S-ISL is a promising agent targeting TSCC through multiple anticancer effects, regulated by its antioxidant mechanism.

Activation and cleavage of SASH1 by caspase-3 mediates an apoptotic response

Apoptosis is a highly regulated cellular process that functions to remove undesired cells from multicellular organisms. This pathway is often disrupted in cancer, providing tumours with a mechanism to avoid cell death and promote growth and survival. The putative tumour suppressor, SASH1 (SAM and SH3 domain containing protein 1), has been previously implicated in the regulation of apoptosis; however, the molecular role of SASH1 in this process is still unclear. In this study, we demonstrate that SASH1 is cleaved by caspase-3 following UVC-induced apoptosis. Proteolysis of SASH1 enables the C-terminal fragment to translocate from the cytoplasm to the nucleus where it associates with chromatin. The overexpression of wild-type SASH1 or a cleaved form of SASH1 representing amino acids 231-1247 leads to an increase in apoptosis. Conversely, mutation of the SASH1 cleavage site inhibits nuclear translocation and prevents the initiation of apoptosis. SASH1 cleavage is also required for the efficient translocation of the transcription factor nuclear factor-κB (NF-κB) to the nucleus. The use of the NF-κB inhibitor DHMEQ demonstrated that the effect of SASH1 on apoptosis was dependent on NF-κB, indicating a codependence between SASH1 and NF-κB for this process.

SASH1 mediates sensitivity of breast cancer cells to chloropyramine and is associated with prognosis in breast cancer

Expression of the SASH1 protein is reduced in a range of human cancers and has been implicated in apoptotic cancer cell death. This study investigated whether increasing SASH1 expression could be a useful therapeutic strategy in breast cancer. Ectopic SASH1 expression increased apoptosis in 7/8 breast cancer cell lines. Subsequent in silico connectivity screening demonstrated that the clinically approved antihistamine drug, chloropyramine, increased SASH1 mRNA levels. Chloropyramine has previously been shown to have anti-tumour activity in breast cancer in part through modulation of FAK signalling, a pathway also regulated by SASH1. This study demonstrated that chloropyramine increased SASH1 protein levels in breast cancer cells. Consistent with this the agent reduced cell confluency in 7/8 cell lines treated irrespective of their ER status but not apoptosis incompetent MCF7 cells. In contrast SASH1 siRNA-transfected breast cancer cells exhibited reduced chloropyramine sensitivity. The prognostic significance of SASH1 expression was also investigated in two breast cancer cohorts. Expression was associated with favourable outcome in ER-positive cases, but only those of low histological grade/proliferative status. Conversely, we found a very strong inverse association in HER2+ disease irrespective of ER status, and in triple-negative, basal-like cases. Overall, the data suggest that SASH1 is prognostic in breast cancer and could have subtype-dependent effects on breast cancer progression. Pharmacologic induction of SASH1 by chloropyramine treatment of breast cancer warrants further preclinical and clinical investigation.

Downregulation of SASH1 correlates with tumor progression and poor prognosis in ovarian carcinoma

SAM- and SH3-domain containing 1 (SASH1) is a recently identified tumor suppressor gene that is required in the tumorigenesis of breast and other solid carcinomas. The SASH1 protein contains SH3 and SAM domains, indicating that it may serve an important role in intracellular signal transduction. The purpose of the present study was to investigate the expression of SASH1 in ovarian carcinoma and the correlation between its expression with clinical pathological features and clinical significance, and the effect of SASH1 on cell proliferation, apoptosis and migration of ovarian SKOV3 cells. The human ovarian carcinoma tissues and adjacent normal tissues were collected following surgery. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to detect the expression levels of SASH1 mRNA and protein, respectively. The expression levels of SASH1 mRNA and protein in ovarian carcinoma tissues were significantly lower than that observed in adjacent normal tissues (P<0.05). The expression levels of SASH1 in samples from patients without lymph nodes metastasis and patients with early FIGO stage was lower than those with lymph nodes metastasis and patients with advanced FIGO stage (P<0.05). Flow cytometry analysis and Transwell invasion chamber experiments were used to investigate the effect of SASH1 on the cell proliferation, apoptosis and migration of SKOV3 cells. The recombinant plasmid pcDNA3.1-SASH1 was constructed and transfected into SKOV3 cells. In addition, the SKOV3 cells in the pcDNA3.1-SASH1 group exhibited significantly reduced cell growth, proliferation, and migration ability compared to the empty vector group and normal group (P<0.01). There were a greater number of apoptotic cells in the pcDNA3.1-SASH1 group compared to the empty vector group and normal group (P<0.01). Taken together, these results indicated that SASH1 may be a tumor suppressor gene in ovarian carcinoma, and SASH1 expression inhibited growth, proliferation and migration, and enhanced apoptosis of SKOV3 cells.

Clinical Significance of SASH1 Expression in Glioma

OBJECTIVE

SAM and SH3 domain containing 1 (SASH1) is a recently discovered tumor suppressor gene. The role of SASH1 in glioma has not yet been described. We investigated SASH1 expression in glioma cases to determine its clinical significance on glioma pathogenesis and prognosis.

METHODS

We produced tissue microarrays using 121 patient-derived glioma samples and 30 patient-derived nontumor cerebral samples. Immunohistochemistry and Western blotting were used to evaluate SASH1 expression. We used Fisher's exact tests to determine relationships between SASH1 expression and clinicopathological characteristics; Cox regression analysis to evaluate the independency of different SASH1 expression; Kaplan-Meier analysis to determine any correlation of SASH1 expression with survival rate.

RESULTS

SASH1 expression was closely correlated with the WHO glioma grade. Of the 121 cases, 66.9% with low SASH1 expression were mostly grade III-IV cases, whereas 33.1% with high SASH1 expression were mostly grades I-II. Kaplan-Meier analysis revealed a significant positive correlation between SASH1 expression and postoperative survival.

CONCLUSIONS

SASH1 was widely expressed in normal and low-grade glioma tissues. SASH1 expression strongly correlated with glioma grades, showing higher expression at a lower grade, which decreased significantly as grade increased. Furthermore, SASH1 expression was positively correlated with better postoperative survival in patients with glioma.

SASH1, a new potential link between smoking and atherosclerosis

OBJECTIVE

We have previously reported that SASH1 expression is increased in circulating human monocytes from smokers and was positively correlated with the number of carotid atherosclerotic plaques. The aim of this study was to further validate the link between smoking, SASH1 and atherosclerosis within the vascular wall and to assess the impact of SASH1 expression on endothelial cell functions.

METHOD

Human carotids with atherosclerotic plaques were obtained from 58 patients (45 of them with known smoking status: smoker, non-smoker, ex-smokers), and were processed for gene expression analyses and immunostaining. To investigate its function, SASH1 was silenced in human aortic endothelial cells (HAECs) using two different siRNA and subcellular localization of SASH1 was determined by immunostaining and subcellular fractionation. Subsequently the transcriptomic analyses and functional experiments (wound healing, WST-1 proliferation or Matrigel assays) were performed to characterize SASH1 function.

RESULTS

SASH1 was expressed in human vascular cells (HAECs, smooth muscle cells) and in monocytes/macrophages. Its tissue expression was significantly higher in the atherosclerotic carotids of smokers compared to non-smokers (p < 0.01). In HAECs, SASH1 was expressed mostly in the cytoplasm and SASH1 knockdown resulted in an increased cell migration, proliferation and angiogenesis. Transcriptomic and pathway analyses showed that SASH1 silencing results in a decreased CYP1A1 expression possibly through the inhibition of TP53 activity.

CONCLUSION

We showed that SASH1 expression is increased in atherosclerotic carotids in smokers and its silencing affects endothelial angiogenic functions; therefore we provide a potential link between smoking and atherosclerosis through SASH1 expression.

Transcriptional profiling provides insights into metronomic cyclophosphamide-activated, innate immune-dependent regression of brain tumor xenografts

Background

Cyclophosphamide treatment on a six-day repeating metronomic schedule induces a dramatic, innate immune cell-dependent regression of implanted gliomas. However, little is known about the underlying mechanisms whereby metronomic cyclophosphamide induces innate immune cell mobilization and recruitment, or about the role of DNA damage and cell stress response pathways in eliciting the immune responses linked to tumor regression.

Methods

Untreated and metronomic cyclophosphamide-treated human U251 glioblastoma xenografts were analyzed on human microarrays at two treatment time points to identify responsive tumor cell-specific factors and their upstream regulators. Mouse microarray analysis across two glioma models (human U251, rat 9L) was used to identify host factors and gene networks that contribute to the observed immune and tumor regression responses.

Results

Metronomic cyclophosphamide increased expression of tumor cell-derived DNA damage, cell stress, and cell death genes, which may facilitate innate immune activation. Increased expression of many host (mouse) immune networks was also seen in both tumor models, including complement components, toll-like receptors, interferons, and cytolysis pathways. Key upstream regulators activated by metronomic cyclophosphamide include members of the interferon, toll-like receptor, inflammatory response, and PPAR signaling pathways, whose activation may contribute to anti-tumor immunity. Many upstream regulators inhibited by metronomic cyclophosphamide, including hypoxia-inducible factors and MAP kinases, have glioma-promoting activity; their inhibition may contribute to the therapeutic effectiveness of the six-day repeating metronomic cyclophosphamide schedule.

Conclusions

Large numbers of responsive cytokines, chemokines and immune regulatory genes linked to innate immune cell recruitment and tumor regression were identified, as were several immunosuppressive factors that may contribute to the observed escape of some tumors from metronomic CPA-induced, immune-based regression. These factors may include useful biomarkers that facilitate discovery of clinically effective immunogenic metronomic drugs and treatment schedules, and the selection of patients most likely to be responsive to immunogenic drug scheduling.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1358-y) contains supplementary material, which is available to authorized users.

Autosomal-recessive SASH1 variants associated with a new genodermatosis with pigmentation defects, palmoplantar keratoderma and skin carcinoma

SASH1 (SAM and SH3 domain-containing protein 1) is a tumor suppressor gene involved in the tumorigenesis of a spectrum of solid cancers. Heterozygous SASH1 variants are known to cause autosomal-dominant dyschromatosis. Homozygosity mapping and whole-exome sequencing were performed in a consanguineous Moroccan family with two affected siblings presenting an unclassified phenotype associating an abnormal pigmentation pattern (hypo- and hyperpigmented macules of the trunk and face and areas of reticular hypo- and hyperpigmentation of the extremities), alopecia, palmoplantar keratoderma, ungueal dystrophy and recurrent spinocellular carcinoma. We identified a homozygous variant in SASH1 (c.1849G>A; p.Glu617Lys) in both affected individuals. Wound-healing assay showed that the patient's fibroblasts were better able than control fibroblasts to migrate. Following the identification of SASH1 heterozygous variants in dyschromatosis, we used reverse phenotyping to show that autosomal-recessive variants of this gene could be responsible for an overlapping but more complex phenotype that affected skin appendages. SASH1 should be added to the list of genes responsible for autosomal-dominant and -recessive genodermatosis, with no phenotype in heterozygous patients in the recessive form, and to the list of genes responsible for a predisposition to skin cancer.

MiR-200a impairs glioma cell growth, migration, and invasion by targeting SIM2-s

Recently, single-minded homolog 2-short form (SIM2-s) was reported to be related to tumor development and progression and to be elevated in many human cancer cells. In this study, we investigated the factors that contribute to the regulation of SIM2-s expression in gliomas. The results showed that SIM2-s was elevated in gliomas. In addition, inhibition of SIM2-s reduced glioma cell growth, migration, and invasion. Next, we demonstrated that SIM2-s is a functional target of miR-200a. Further, miR-200a is downregulated in human glioma and inhibition of miR-200a caused upregulation of SIM2-s in T98G cells and promoted their motility. Finally, blockage of miR-200a expression in a mouse model of human glioma resulted in significant promotion of tumor growth. These findings suggest that miR-200a could serve as a therapeutic tool for glioma.

Systematic review of protein biomarkers of invasive behavior in glioblastoma

Glioblastoma (GBM) is an aggressive and incurable brain tumor with a grave prognosis. Recurrence is inevitable even with maximal surgical resection, in large part because GBM is a highly invasive tumor. Invasiveness also contributes to the failure of multiple cornerstones of GBM therapy, including radiotherapy, temozolomide chemotherapy, and vascular endothelial growth factor blockade. In recent years there has been significant progress in the identification of protein biomarkers of invasive phenotype in GBM. In this article, we comprehensively review the literature and survey a broad spectrum of biomarkers, including proteolytic enzymes, extracellular matrix proteins, cell adhesion molecules, neurodevelopmental factors, cell signaling and transcription factors, angiogenic effectors, metabolic proteins, membrane channels, and cytokines and chemokines. In light of the marked variation seen in outcomes in GBM patients, the systematic use of these biomarkers could be used to form a framework for better prediction, prognostication, and treatment selection, as well as the identification of molecular targets for further laboratory investigation and development of nascent, directed therapies.

Clinical significance of expression of SASH1 in esophageal squamous cell carcinoma

AIM: To detect the expression of SAM- and SH3-domain containing 1 (SASH1) in human esophageal squamous cell carcinoma (ESCC), and to analyze the relationship between SASH1 expression and clinical and pathological parameters of ESCC.

METHODS: The expression of SASH1 was detected by immunohistochemistry in 72 ESCC specimens and 40 tumor-adjacent specimens.

RESULTS: The positive rate of SASH1 protein expression in ESCC was significantly lower than that in tumor-adjacent non-carcinoma tissue (41.67% vs 80.00%, P < 0.001). The positive rate of SASH1 protein expression was significantly higher in patients without lymph node metastasis than in those with lymph node metastasis (χ² = 6.583, P < 0.05). Expression of SASH1 was associated with tumor differentiation and TNM stage in ESCC (both P < 0.05).

CONCLUSION: Down-regulation of SASH1 expression occurs in ESCC. SASH1 may be a novel tumor suppressor in ESCC and can be used as a molecular maker for the diagnosis and treatment of ESCC.

CARMA3 is overexpressed in human glioma and promotes cell invasion through MMP9 regulation in A172 cell line

Caspase recruitment domain-containing membrane-associated guanylate kinase protein 10 or CARMA3 (CARD10) is a recently characterized oncoprotein involved in the progression of several human malignancies. The present study aims to investigate the expression pattern and biological roles of CARMA3 protein in human glioma. CARMA3 expression was analyzed in 97 glioma specimens using immunohistochemistry. We observed negative staining in normal astrocytes and positive staining of CARMA3 in 25 out of 97 (25.8%) glioma samples. Overexpression of CARMA3 correlated with tumor grade (p < 0.001). Small interfering RNA knockdown was performed in A172 cell line with relatively high CARMA3 expression. Using colony formation assay and Matrigel invasion assay, we showed that CARMA3 depletion in A172 cell line inhibited cell proliferation and cell invasion. In addition, mRNA and protein levels of matrix metallopeptidase 9 (MMP9) were downregulated, indicating CARMA3 might regulate invasion through MMP9. In conclusion, CARMA3 serves as an oncoprotein in human glioma by regulating cell invasion, possibly through MMP9 regulation.