Sec62 promotes early recurrence of hepatocellular carcinoma through activating integrinα/CAV1 signalling

Dual Sec62/Ki67 immunocytochemistry of liquid-based cytological preparations represents a highly valid biomarker for non-invasive detection of head and neck squamous cell carcinomas

BACKGROUND

Head and neck squamous cell carcinomas (HNSCC) are frequently diagnosed in advanced stages, which limits therapeutic options and results in persistently poor patient outcomes. The aim of this study was to use liquid-based swab cytology (LBC) in combination with dual immunocytochemical detection of migration and proliferation markers Sec62 and Ki67 in order to allow non-invasive early detection of HNSCC as well as to analyse the diagnostic validity of this method for predicting the malignancy of suspicious oral lesions.

METHODS

104 HNSCC patients and 28 control patients, including healthy patients (n = 17), papilloma (n = 1) and leukoplakia patients (n = 10), were included in this study. For all patients, an LBC swab followed by simultaneous immunocytochemical detection of Sec62 and Ki67 was performed. Immunocytochemical as well as cytopathological results were correlated with histological diagnoses and clinical findings.

RESULTS

All HNSCC patients (100%) showed dual Sec62/Ki67 positivity, and all control patients except for the papilloma patient were negative for Sec62/Ki67 (96.4%), resulting in a 100% sensitivity and 96.4% specificity of Sec62/Ki67 dual stain for non-invasive detection of HNSCC. The positive predictive value was 99% and the negative predictive value was 100%. Sec62 expression levels showed a positive correlation with tumour de-differentiation (p = 0.0489).

CONCLUSION

Simultaneous immunocytochemical detection of Sec62/Ki67 using LBC represents a promising non-invasive and easy-to-apply tool for the early detection of HNSCC in routine clinical practice. This novel technique can help to avoid incisional biopsies and reduce the frequency with which general anaesthesia is used in diagnostic procedures in patients with suspicious oral lesions.

Integrins in human hepatocellular carcinoma tumorigenesis and therapy

ABSTRACT

Integrins are a family of transmembrane receptors that connect the extracellular matrix and actin skeleton, which mediate cell adhesion, migration, signal transduction, and gene transcription. As a bi-directional signaling molecule, integrins can modulate many aspects of tumorigenesis, including tumor growth, invasion, angiogenesis, metastasis, and therapeutic resistance. Therefore, integrins have a great potential as antitumor therapeutic targets. In this review, we summarize the recent reports of integrins in human hepatocellular carcinoma (HCC), focusing on the abnormal expression, activation, and signaling of integrins in cancer cells as well as their roles in other cells in the tumor microenvironment. We also discuss the regulation and functions of integrins in hepatitis B virus-related HCC. Finally, we update the clinical and preclinical studies of integrin-related drugs in the treatment of HCC.

NUSAP1, a novel stemness-related protein, promotes early recurrence of hepatocellular carcinoma

Early recurrence (within 2 years after resection) is the primary cause of poor outcomes among hepatocellular carcinoma (HCC) patients, and liver cancer stem cells are the main contributors to postsurgical HCC recurrence. Nucleolar and spindle-associated protein 1 (NUSAP1) has been reported to be involved in tumor progression. We investigated the function and clinical value of NUSAP1 in early recurrence of HCC. Data from public datasets and our cohort were used to assess the association between NUSAP1 expression and early HCC recurrence. Gain- and loss-of-function experiments were carried out in vivo and in vitro. The predictive effect of NUSAP1 on early HCC recurrence was further evaluated by a validation cohort. We found that elevated NUSAP1 expression in HCC specimens was correlated with poor outcome, especially in cases with postoperative early recurrence. Functional studies indicated that NUSAP1 significantly promotes HCC progression. A postsurgical recurrence murine model further revealed that upregulated NUSAP1 dramatically increased the likelihood of HCC early recurrence. RNA sequencing data revealed that the gene sets of cancer stemness and the signal transducer and activator of transcription 3 (STAT3) pathway were enriched by NUSAP1 overexpression. Mechanistically, NUSAP1 enhanced cancer stemness through stimulating STAT3 nuclear translocation and activation through receptor of activated protein C kinase 1 (RACK1). In a validation cohort with 112 HCC patients, NUSAP1 effectively predicted HCC early recurrence. Our results indicated that NUSAP1 promotes early recurrence of HCC by sustaining cancer stemness and could serve as a valuable predictive indicator for postsurgical intervention in HCC patients.

PRP8-Induced CircMaml2 Facilitates the Healing of the Intestinal Mucosa via Recruiting PTBP1 and Regulating Sec62

BACKGROUND

Multiple organ dysfunction syndrome (MODS) occurs in the gastrointestinal tract and injured intestinal mucosa is the anatomical basis for various diseases. The expression of circular RNAs (circRNAs) is implicated in many diseases; however, the role of circRNAs in intestinal mucosal injury is yet to be discovered. Our preliminary gene microarray analysis revealed a novel circular RNA, circMaml2, with a significant intestinal mucosal protection effect. Its expression was found to decrease in severely burned intestinal mucosal tissue, whereas its overexpression might facilitate the reconstruction of the injured intestinal mucous membrane.

METHODS

The function of circMaml2 in cell proliferation and migration was studied in MC38 cells. The repair function of circMaml2 was tested on the intestinal mucosa of mice. RNA-binding protein polypyrimidine tract-binding protein 1(PTBP1) was selected by pull-down assay and mass spectrometry (MS). RNA immunoprecipitation (RIP) was performed to confirm the binding of circMaml2 and PTBP1 and to study PTBP1 and its downstream target, early B-cell factor 1(Ebf1). Bioinformatics software forecast analysis and dual-luciferase reporter assay were performed to ascertain miR-683 and Sec62 as the downstream targets of circMaml2 and miR-683, respectively. Furthermore, PRP8 was discovered to promote the biogenesis of circMaml2.

RESULTS

CircMaml2 promotes cell proliferation and migration of MC38 cells and the repair of the intestinal mucosa of mice. This effect is brought about by combining with PTBP1 to improve Ebf1 and interacting with miR-683 to regulate Sec2. Furthermore, PRP8 was discovered to promote the biogenesis of circMaml2.

CONCLUSIONS

This is the first reported study of the effect of circMaml2 on intestinal mucosal repair.

Endoplasmic reticulum-resident protein Sec62 drives colorectal cancer metastasis via MAPK/ATF2/UCA1 axis

OBJECTIVE

Metastasis is responsible for the poor prognosis of patients with colorectal cancer (CRC), and the role of aberrant expression of endoplasmic reticulum (ER) receptors in tumour metastasis has not been fully elucidated. The aim of the study is to ensure the role of ER-resident protein Sec62 in CRC metastasis and illuminate associated molecular mechanisms.

MATERIALS AND METHODS

Bioinformatics analysis, qRT-PCR, western blot and immunohistochemistry assays were performed to evaluate the expression level and clinical significance of Sec62 in CRC. The specific role of Sec62 in CRC was identified by a series of functional experiments. We conducted RNA sequencing and rescue experiments to analyse the differentially expressed genes and identified UCA1 as a novel pro-metastasis target of Sec62 in CRC. Besides, the efficacy of MAPK/JNK inhibitor or agonist on Sec62-mediated CRC metastasis was evaluated by trans-well and wound healing assays. Finally, luciferase reporter and ChIP assay were employed to further explore the potential mechanisms.

RESULTS

The abnormally elevated expression of Sec62 predicted poor prognosis of CRC patients and facilitated malignant metastasis of CRC cells. Mechanistically, Sec62 enhanced UCA1 expression through activating MAPK/JNK signalling pathway. And the p-JNK activating ATF2 could transcriptionally regulate UCA1 expression. Furthermore, blocking or activating MAPK/JNK signalling with JNK inhibitor or agonist potently suppressed or enhanced Sec62 mediated CRC metastatic process.

CONCLUSIONS

Our study reports for the first time that the Sec62/MAPK/ATF2 /UCA1 axis exists in CRC metastatic process, which could be a potential treatment target of metastatic CRC.

The endoplasmic reticulum membrane protein Sec62 as potential therapeutic target in SEC62 overexpressing tumors

The human SEC62 gene is located on chromosome 3q, was characterized as a tumor driver gene and is found to be overexpressed in an ever-growing number of tumors, particularly those with 3q26 amplification. Where analyzed, SEC62 overexpression was associated with poor prognosis. Sec62 protein is a membrane protein of the endoplasmic reticulum (ER) and has functions in endoplasmic reticulum protein import, endoplasmic reticulum-phagy and -in cooperation with the cytosolic protein calmodulin- the maintenance of cellular calcium homeostasis. Various human tumors show SEC62 overexpression in immunohistochemistry and corresponding cell lines confirm this phenomenon in western blots and immunofluorescence. Furthermore, these tumor cells are characterized by increased stress tolerance and migratory as well as invasive potential, three hallmarks of cancer cells. Strikingly, plasmid-driven overexpression of SEC62 in non-SEC62 overexpressing cells introduces the same three hallmarks of cancer into the transfected cells. Depletion of Sec62 from either type of SEC62 overexpressing tumor cells by treatment with SEC62-targeting siRNAs leads to reduced stress tolerance and reduced migratory as well as invasive potential. Where tested, treatment of SEC62 overexpressing tumor cells with the small molecule/calmodulin antagonist trifluoperazine (TFP) phenocopied the effect of SEC62-targeting siRNAs. Recently, first phase II clinical trials with the prodrug mipsagargin/G202, which targets cellular calcium homeostasis in prostate cells as well as neovascular tissue in various tumors were started. According to experiments with tumor cell lines, however, SEC62 overexpressing tumor cells may be less responsive or resistant against such treatment. Therefore, murine tumor models for tumor growth or metastasis were evaluated with respect to their responsiveness to treatment with a mipsagargin analog (thapsigargin), or trifluoperazine, which had previously been in clinical use for the treatment of schizophrenia, or with the combination of both drugs. So far, no additive effect of the two drugs was observed but trifluoperazine had an inhibitory effect on tumor growth and metastatic potential in the models. Here, we review the state of affairs.

Role of the SEC62 gene in dermato-oncology - impact on tumor cell biology, prognostication, and personalized therapy management

The SEC62 gene encodes for a transmembrane protein of the endoplasmic reticulum (ER). Sec62 protein is involved in the post-translational transport of secretory and membrane-bound proteins in eukaryotic cells, regulates intracellular calcium homeostasis through direct interaction with the Sec61 channel and makes a decisive contribution to the cellular compensation of ER stress in the context of recovER-phagy. A significantly increased expression of the SEC62 gene has already been demonstrated in various tumor entities. First approaches of a targeted therapy have been tested for various tumor entities in vitro and in vivo with promising results that motivate further preclinical and clinical studies. Nevertheless, many questions remain unanswered, in particular with regard to the molecular mechanisms underlying the observed clinical effects, and require further investigation in future studies. The protein also plays a relevant role in dermato-oncology. The overexpression of SEC62 in atypical fibroxanthomas and malignant melanomas has already been demonstrated and a correlation of SEC62 expression with various clinical and pathological features has been observed. Future studies, especially in vivo and clinical, will show whether Sec62 can be established as a prognostic marker in dermato-oncology and whether it can serve as a starting point for targeted therapy.

Antagonizing Sec62 function in intracellular Ca2+ homeostasis represents a novel therapeutic strategy for head and neck cancer

Various cancer types including head and neck squamous cell carcinomas (HNSCC) show a frequent amplification of chromosomal region 3q26 that encodes, among others, for the SEC62 gene. Located in the ER membrane, this translocation protein is known to play a critical role as a potential driver oncogene in cancer development. High SEC62 expression levels were observed in various cancer entities and were associated with a poor outcome and increased metastatic burden. Because of its intracellular localization the SEC62 protein is poorly accessible for therapeutic antibodies, therefore a functional SEC62 knockdown represents the most promising mechanism of a potential antineoplastic targeted therapy. By stimulating the Ca2+ efflux from the ER lumen and thereby increasing cellular stress levels, a functional inhibition of SEC62 bears the potential to limit tumor growth and metastasis formation. In this study, two potential anti-metastatic and -proliferative agents that counteract SEC62 function were investigated in functional in vitro assays by utilizing an immortalized human hypopharyngeal cancer cell line as well as a newly established orthotopic murine in vivo model. Additionally, a CRISPR/Cas9 based SEC62 knockout HNSCC cell line was generated and functionally characterized for its relevance in HNSCC cell proliferation and migration as well as sensitivity to SEC62 targeted therapy in vitro.

Sec62 promotes pro-angiogenesis of hepatocellular carcinoma cells under hypoxia

This study aimed to investigate the underlying molecular pathogenic mechanism of Sec62 in hepatocellular carcinoma (HCC). Microarray analysis was conducted to profile the global gene expression in the HCC cell line Huh7 cells transfected with Sec62high vs. NC and Sec62low vs. NC. Ingenuity pathway analysis and gene set enrichment analysis were used to perform Sec62-related signaling pathway analysis from screened differentially expressed genes (DEGs). A protein-protein interaction network was constructed. Experimental validation of the expression of key DEGs was conducted. Hypoxia-induced tube formation was undertaken to investigate the role of Sec62 in angiogenesis. A total of 74 intersected DEGs were identified from Huh7 cells with Sec62high vs. NC and Sec62low vs. NC. Among them, 65 DEGs were correlated with the expression of Sec62. The P53 signaling pathway was found to be enriched in Huh7 cells with Sec62high vs. NC, while the acute phase response signaling pathway was enriched in Huh7 cells with Sec62low vs. NC. DEGs, such as serine protease inhibitor E (SERPINE) and tumor necrosis factor receptor superfamily, member 11B (TNFRSF11B), were not only identified as the lead genes of these enriched pathways, but were also found to be closely related to Sec62. Moreover, knockdown of Sec62 decreased the expression of SERPINE1 (plasminogen activator inhibitor type 1 (PAI-1)) and TNFRSF11B, whereas overexpression of Sec62 had the opposite effects. In addition, knockdown of Sec62 inhibited hypoxia-induced tube formation via PAI-1. Sec62 promoted pro-angiogenesis of HCC under hypoxia by regulating PAI-1, and it may be a crucial angiogenic switch in HCC.

Complexity and Specificity of Sec61-Channelopathies: Human Diseases Affecting Gating of the Sec61 Complex

The rough endoplasmic reticulum (ER) of nucleated human cells has crucial functions in protein biogenesis, calcium (Ca2+) homeostasis, and signal transduction. Among the roughly one hundred components, which are involved in protein import and protein folding or assembly, two components stand out: The Sec61 complex and BiP. The Sec61 complex in the ER membrane represents the major entry point for precursor polypeptides into the membrane or lumen of the ER and provides a conduit for Ca2+ ions from the ER lumen to the cytosol. The second component, the Hsp70-type molecular chaperone immunoglobulin heavy chain binding protein, short BiP, plays central roles in protein folding and assembly (hence its name), protein import, cellular Ca2+ homeostasis, and various intracellular signal transduction pathways. For the purpose of this review, we focus on these two components, their relevant allosteric effectors and on the question of how their respective functional cycles are linked in order to reconcile the apparently contradictory features of the ER membrane, selective permeability for precursor polypeptides, and impermeability for Ca2+. The key issues are that the Sec61 complex exists in two conformations: An open and a closed state that are in a dynamic equilibrium with each other, and that BiP contributes to its gating in both directions in cooperation with different co-chaperones. While the open Sec61 complex forms an aqueous polypeptide-conducting- and transiently Ca2+-permeable channel, the closed complex is impermeable even to Ca2+. Therefore, we discuss the human hereditary and tumor diseases that are linked to Sec61 channel gating, termed Sec61-channelopathies, as disturbances of selective polypeptide-impermeability and/or aberrant Ca2+-permeability.

Sec62 promotes stemness and chemoresistance of human colorectal cancer through activating Wnt/β-catenin pathway

BACKGROUND

Cancer stem cell (CSC)-related chemoresistance leads to poor outcome of the patients with colorectal cancer (CRC). In this study, we identified the chemoresistance-relevant molecules and decipher the involved mechanisms to provide potential therapeutic target for CRC. We focused on Sec62, a novel target with significantly increased expression in chemoresistant CRC tissues, and further investigated its role in the progression of CRC.

METHODS

Through analyzing the differentially-expressed genes between chemoresistant and chemosensitive CRCs, we selected Sec62 as a novel chemoresistance-related target in CRC. The expression and clinical significance of Sec62 were determined by immunoblotting and immunohistochemistry in tissues and cell lines of CRC. The roles of Sec62 in drug resistance, stemness and tumorigenesis were evaluated in vitro and in vivo using functional experiments. GST pull-down, western blot, coimmunoprecipitation and Me-RIP assays were performed to further explore the downstream molecular mechanisms.

RESULTS

Sec62 upregulation was associated with the chemoresistance of CRC and poor outcome of CRC patients. Depletion of Sec62 sensitized CRC cells to chemotherapeutic drugs. Sec62 promoted the stemness of CRC cells through activating Wnt/β-catenin signaling. Mechanistically, Sec62 bound to β-catenin and inhibited the degradation of β-catenin. Sec62 competitively disrupted the interaction between β-catenin and APC to inhibit the β-catenin destruction complex assembly. Moreover, Sec62 expression was upregulated by the m6A-mediated stabilization of Sec62 mRNA.

CONCLUSIONS

Sec62 upregulated by the METTL3-mediated m6A modification promotes the stemness and chemoresistance of CRC by binding to β-catenin and enhancing Wnt signalling. Thus, m6A modification-Sec62-β-catenin molecular axis might act as therapeutic targets in improving treatment of CRC.

SEC62 and SEC63 Expression in Hepatocellular Carcinoma and Tumor-Surrounding Liver Tissue

Introduction

The endoplasmic reticulum transmembrane proteins Sec61, Sec62, and Sec63 are responsible for the intracellular trafficking of precursor proteins and affect intracellular signaling. SEC62 overexpression has been linked to various human cancers. Our aim was to investigate SEC62 and SEC63 expression in hepatocellular carcinoma (HCC) and surrounding liver tissue.

Patients and Methods

Primary liver tissue was collected from 11 consecutive patients (70 ± 9 years; 10 men) who underwent HCC resection. In the HCC and the tumor-surrounding liver tissue we investigated SEC62 und SEC63 mRNA expression using quantitative real-time PCR. For Sec62, immunohistochemistry was performed.

Results

SEC62and SEC63 total mRNA contents were significantly (p = 0.001) higher in HCCs (C_T 22.5 ± 0.4 and 22.6 ± 0.3) when compared to the surrounding tissue (C_T 24.6 ± 0.6 and 25.1 ± 0.9). Using the comparative C_Tmethod, SEC62 and SEC63 expression in HCC was increased 5- and 8.1-fold, respectively, in comparison to surrounding tissue. For Sec62 immunohistochemistry, the mean immunoreactive scores (IRS) were 7.9 ± 2.9 for HCC and 4.8 ± 1.2 for non-tumorous liver (p = 0.027). The mean IRS in HCC were 5.7 ± 3.5 and 8.9 ± 2.3 for patients without (n = 3) and with tumor recurrence (n = 8), respectively.

Conclusions

Overexpression of SEC62 and SEC63 is a common feature of HCC. The role of Sec62 as a prognostic marker for tumor recurrence after surgery and its potential role in treatment stratification must be addressed in future studies.

Recent progress in treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death worldwide. In the past decade, there have been improvements in non-drug therapies and drug therapies for HCC treatment. Non-drug therapies include hepatic resection, liver transplantation, transarterial chemoembolization (TACE) and ablation. The former two surgical treatments are beneficial for patients with early and mid-stage HCC. As the first choice for non-surgical treatment, different TACE methods has been developed and widely used in combination therapy. Ablation has become an important alternative therapy for the treatment of small HCC or cases of unresectable surgery. Meanwhile, the drugs including small molecule targeted drugs like sorafenib and lenvatinib, monoclonal antibodies such as nivolumab are mainly used for the systematic treatment of advanced HCC. Besides strategies described above are recommended as first-line therapies due to their significant increase in mean overall survival, there are also potential drugs in clinical trials or under preclinical development. In addition, a number of potential preclinical surgical or adjuvant therapies are being studied, such as oncolytic virus, mesenchymal stem cells, biological clock, gut microbiome composition and peptide vaccine, all of which have shown different degrees of inhibition on HCC. With some potential anti-HCC drugs being reported, many promising therapeutic targets in related taxonomic signaling pathways including cell cycle, epigenetics, tyrosine kinase and so on that affect the progression of HCC have also been found. Together, the rational application of existing therapies and drugs as well as the new strategies will bring a bright future for the global cure of HCC in the coming decades.

A robust twelve-gene signature for prognosis prediction of hepatocellular carcinoma

Background

The prognosis of hepatocellular carcinoma (HCC) patients remains poor. Identifying prognostic markers to stratify HCC patients might help to improve their outcomes.

Methods

Six gene expression profiles (GSE121248, GSE84402, GSE65372, GSE51401, GSE45267 and GSE14520) were obtained for differentially expressed genes (DEGs) analysis between HCC tissues and non-tumor tissues. To identify the prognostic genes and establish risk score model, univariable Cox regression survival analysis and Lasso-penalized Cox regression analysis were performed based on the integrated DEGs by robust rank aggregation method. Then Kaplan-Meier and time-dependent receiver operating characteristic (ROC) curves were generated to validate the prognostic performance of risk score in training datasets and validation datasets. Multivariable Cox regression analysis was used to identify independent prognostic factors in liver cancer. A prognostic nomogram was constructed based on The Cancer Genome Atlas (TCGA) dataset. Finally, the correlation between DNA methylation and prognosis-related genes was analyzed.

Results

A twelve-gene signature including SPP1, KIF20A, HMMR, TPX2, LAPTM4B, TTK, MAGEA6, ANX10, LECT2, CYP2C9, RDH16 and LCAT was identified, and risk score was calculated by corresponding coefficients. The risk score model showed a strong diagnosis performance to distinguish HCC from normal samples. The HCC patients were stratified into high-risk and low-risk group based on the cutoff value of risk score. The Kaplan-Meier survival curves revealed significantly favorable overall survival in groups with lower risk score (P < 0.0001). Time-dependent ROC analysis showed well prognostic performance of the twelve-gene signature, which was comparable or superior to AJCC stage at predicting 1-, 3-, and 5-year overall survival. In addition, the twelve-gene signature was independent with other clinical factors and performed better in predicting overall survival after combining with age and AJCC stage by nomogram. Moreover, most of the prognostic twelve genes were negatively correlated with DNA methylation in HCC tissues, which SPP1 and LCAT were identified as the DNA methylation-driven genes.

Conclusions

We identified a twelve-gene signature as a robust marker with great potential for clinical application in risk stratification and overall survival prediction in HCC patients.