Anti-cancer Activity of Novel TM4SF5-Targeting Antibodies through TM4SF5 Neutralization and Immune Cell-Mediated Cytotoxicity

Isoxazole-based molecules restore NK cell immune surveillance in hepatocarcinogenesis by targeting TM4SF5 and SLAMF7 linkage

Dynamic communication between hepatocytes and the environment is critical in hepatocellular carcinoma (HCC) development. Clinical immunotherapy against HCC is currently unsatisfactory and needs more systemic considerations, including the identification of new biomarkers and immune checkpoints. Transmembrane 4 L six family member 5 (TM4SF5) is known to promote HCC, but it remains unclear how cancerous hepatocytes avoid immune surveillance and whether avoidance can be blocked. We investigated how TM4SF5-mediated hepatic tumorigenesis avoids surveillance by natural killer (NK) cells, which are prevalent in the liver, and whether the avoidance can be blocked by anti-TM4SF5 agents. We used comprehensive structure activity relationship analysis to identify TM4SF5-specific isoxazole (TSI)-based small molecules that inhibit TM4SF5-mediated effects. TM4SF5 expressed by hepatocytes reduced NK cell cytotoxicity by downregulating stimulatory ligands/receptors, including signaling lymphocytic activation molecule family member 7 (SLAMF7). TM4SF5 bound SLAMF7 depending on N-glycosylation and caused intracellular trafficking of SLAMF7 from the plasma membrane to lysosomes for degradation. TSI treatments in cell lines and animal models of HCC blocked this binding, intracellular trafficking, and downregulation, resulting in higher levels of stimulatory NK cell ligands. In mouse xenograft models, TSI treatment abrogated HCC development by increasing the abundance and dispersion of Slamf7-positive cells in liver tissues, recapitulating the phenotype of Tm4sf5-knockout mice and indicating TSI-mediated restoration of NK cell surveillance. These findings suggest that TSIs can inhibit TM4SF5-mediated liver carcinogenesis by increasing NK cell surveillance.

TMO-Net: an explainable pretrained multi-omics model for multi-task learning in oncology

Cancer is a complex disease composing systemic alterations in multiple scales. In this study, we develop the Tumor Multi-Omics pre-trained Network (TMO-Net) that integrates multi-omics pan-cancer datasets for model pre-training, facilitating cross-omics interactions and enabling joint representation learning and incomplete omics inference. This model enhances multi-omics sample representation and empowers various downstream oncology tasks with incomplete multi-omics datasets. By employing interpretable learning, we characterize the contributions of distinct omics features to clinical outcomes. The TMO-Net model serves as a versatile framework for cross-modal multi-omics learning in oncology, paving the way for tumor omics-specific foundation models.

Anoikis-related gene signature is associated with immune infiltration and predicts the prognosis of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common histological type of lung cancer. With the in-depth exploration of cell death manners, numerous studies found that anoikis is an important mechanism that associated with treatment. Therefore, we aimed to explore the prognostic value and treatment guidance of anoikis in NSCLC patients. In the current study, we first constructed a prognostic model based on the anoikis-related genes based on bulk RNA-sequencing and single-cell RNA-sequencing (scRNA-seq) dataset. Then, immuno-correlations of anoikis-related risk scores (ARGRS) were analyzed. In addition, HMGA1, a risky gene in ARGRS, was further explored to define its expression and immuno-correlation. Results showed that patients with higher ARGRS had worse clinical outcomes. Moreover, the five genes in the prognostic model were all highly expressed on tumor cells. Moreover, further analysis found that the ARGRS was negatively correlated with ImmuneScore, but positively with tumor purity. Besides, patients in the ARGRS-high group had lower levels of immunological characteristics, such as the immune-related signaling pathways and subpopulations. Additionally, in the immunotherapy cohorts, patients with the ARGRS-high phenotype were more resistant to immunotherapy and tended to not achieve remission after treatment. Last, HMGA1 was chosen as the representative biomarker, and analysis of the in-house cohort showed that HMGA1 was highly expressed in tumor tissues and correlated with decreased T cell infiltration. To sum up, ARGRS was correlated with a desert tumor microenvironment and identified immune-cold tumors, which can be a novel biomarker for the recognition of immunological characteristics and an immunotherapeutic response in NSCLC.

Three Members of Transmembrane-4-Superfamily, TM4SF1, TM4SF4, and TM4SF5, as Emerging Anticancer Molecular Targets against Cancer Phenotypes and Chemoresistance

There are six members of the transmembrane 4 superfamily (TM4SF) that have similar topology and sequence homology. Physiologically, they regulate tissue differentiation, signal transduction pathways, cellular activation, proliferation, motility, adhesion, and angiogenesis. Accumulating evidence has demonstrated, among six TM4SF members, the regulatory roles of transmembrane 4 L6 domain family members, particularly TM4SF1, TM4SF4, and TM4SF5, in cancer angiogenesis, progression, and chemoresistance. Hence, targeting derailed TM4SF for cancer therapy has become an emerging research area. As compared to others, this review aimed to present a focused insight and update on the biological roles of TM4SF1, TM4SF4, and TM4SF5 in the progression, metastasis, and chemoresistance of various cancers. Additionally, the mechanistic pathways, diagnostic and prognostic values, and the potential and efficacy of current anti-TM4SF antibody treatment were also deciphered. It also recommended the exploration of other interactive molecules to be implicated in cancer progression and chemoresistance, as well as potential therapeutic agents targeting TM4SF as future perspectives. Generally, these three TM4SF members interact with different integrins and receptors to significantly induce intracellular signaling and regulate the proliferation, migration, and invasion of cancer cells. Intriguingly, gene silencing or anti-TM4SF antibody could reverse their regulatory roles deciphered in different preclinical models. They also have prognostic and diagnostic value as their high expression was detected in clinical tissues and cells of various cancers. Hence, TM4SF1, TM4SF4, and TM4SF5 are promising therapeutic targets for different cancer types preclinically and deserve further investigation.

Systemic TM4SF5 overexpression in ApcMin/+ mice promotes hepatic portal hypertension associated with fibrosis

Mutation of the gene for adenomatous polyposis coli (APC), as seen in Apc^Min/+ mice, leads to intestinal adenomas and carcinomas via stabilization of β-catenin. Transmembrane 4 L six family member 5 (TM4SF5) is involved in the development of non-alcoholic fatty liver disease, fibrosis, and cancer. However, the functional linkage between TM4SF5 and APC or β-catenin has not been investigated for pathological outcomes. After interbreeding Apc^Min/+ with TM4SF5-overexpressing transgenic (Tg^TM4SF5) mice, we explored pathological outcomes in the intestines and livers of the offspring. The intestines of 26-week-old dual-transgenic mice (Apc^Min/+:Tg^TM4SF5) had intramucosal adenocarcinomas beyond the single-crypt adenomas in Apc^Min/+ mice. Additional TM4SF5 overexpression increased the stabilization of β-catenin via reduced glycogen synthase kinase 3β (GSK3β) phosphorylation on Ser9. Additionally, the livers of the dualtransgenic mice showed distinct sinusoidal dilatation and features of hepatic portal hypertension associated with fibrosis, more than did the relatively normal livers in Apc^Min/+ mice. Interestingly, TM4SF5 overexpression in the liver was positively linked to increased GSK3β phosphorylation (opposite to that seen in the colon), β-catenin level, and extracellular matrix (ECM) protein expression, indicating fibrotic phenotypes. Consistent with these results, 78-week-old Tg^TM4SF5 mice similarly had sinusoidal dilatation, immune cell infiltration, and fibrosis. Altogether, systemic overexpression of TM4SF5 aggravates pathological abnormalities in both the colon and the liver. [BMB Reports 2022; 55(12): 609-614].

Systemic TM4SF5 overexpression in ApcMin/+ mice promotes hepatic portal hypertension associated with fibrosis

Mutation of the gene for adenomatous polyposis coli (APC), as seen in ApcMin/+ mice, leads to intestinal adenomas and carcinomas via stabilization of β-catenin. Transmembrane 4 L six family member 5 (TM4SF5) is involved in the development of non-alcoholic fatty liver disease, fibrosis, and cancer. However, the functional linkage between TM4SF5 and APC or β-catenin has not been investigated for pathological outcomes. After interbreeding ApcMin/+ with TM4SF5-overexpressing transgenic (TgTM4SF5) mice, we explored pathological outcomes in the intestines and livers of the offspring. The intestines of 26-week-old dual-transgenic mice (ApcMin/+:TgTM4SF5) had intramucosal adenocarcinomas beyond the single-crypt adenomas in ApcMin/+ mice. Additional TM4SF5 overexpression increased the stabilization of β-catenin via reduced glycogen synthase kinase 3β (GSK3β) phosphorylation on Ser9. Additionally, the livers of the dualtransgenic mice showed distinct sinusoidal dilatation and features of hepatic portal hypertension associated with fibrosis, more than did the relatively normal livers in ApcMin/+ mice. Interestingly, TM4SF5 overexpression in the liver was positively linked to increased GSK3β phosphorylation (opposite to that seen in the colon), β-catenin level, and extracellular matrix (ECM) protein expression, indicating fibrotic phenotypes. Consistent with these results, 78-week-old TgTM4SF5 mice similarly had sinusoidal dilatation, immune cell infiltration, and fibrosis. Altogether, systemic overexpression of TM4SF5 aggravates pathological abnormalities in both the colon and the liver. [BMB Reports 2022; 55(12): 609-614].

TM4SF5-Mediated Regulation of Hepatocyte Transporters during Metabolic Liver Diseases

Nonalcoholic fatty liver disease (NAFLD) is found in up to 30% of the world’s population and can lead to hepatocellular carcinoma (HCC), which has a poor 5-year relative survival rate of less than 40%. Clinical therapeutic strategies are not very successful. The co-occurrence of metabolic disorders and inflammatory environments during the development of steatohepatitis thus needs to be more specifically diagnosed and treated to prevent fatal HCC development. To improve diagnostic and therapeutic strategies, the identification of molecules and/or pathways responsible for the initiation and progression of chronic liver disease has been explored in many studies, but further study is still required. Transmembrane 4 L six family member 5 (TM4SF5) has been observed to play roles in the regulation of metabolic functions and activities in hepatocytes using in vitro cell and in vivo animal models without or with TM4SF5 expression in addition to clinical liver tissue samples. TM4SF5 is present on the membranes of different organelles or vesicles and cooperates with transporters for fatty acids, amino acids, and monocarbohydrates, thus regulating nutrient uptake into hepatocytes and metabolism and leading to phenotypes of chronic liver diseases. In addition, TM4SF5 can remodel the immune environment by interacting with immune cells during TM4SF5-mediated chronic liver diseases. Because TM4SF5 may act as an NAFLD biomarker, this review summarizes crosstalk between TM4SF5 and nutrient transporters in hepatocytes, which is related to chronic liver diseases.

Therapeutic effects of TM4SF5-targeting chimeric and humanized monoclonal antibodies in hepatocellular and colon cancer models

The transmembrane 4 L six family member 5 (TM4SF5) is aberrantly expressed in hepatocellular and colorectal cancers, and has been implicated in tumor progression, suggesting that it could serve as a novel therapeutic target. Previously, we screened a murine antibody phage-display library to generate a novel monoclonal antibody, Ab27, that is specific to the extracellular loop 2 of TM4SF5. In this study, we evaluated the effects of chimeric Ab27 using cancer cells expressing endogenous TM4SF5 or stably overexpressing TM4SF5 in vivo and in vitro. Monotherapy with Ab27 significantly decreased tumor growth in liver and colon cancer xenograft models, including a sorafenib-resistant model, and decreased the phosphorylation of focal adhesion kinase (FAK), p27^Kip1, and signal transducer and activator of transcription 3 (STAT3). No general Ab27 toxicity was observed in vivo. Combination treatment with Ab27 and sorafenib or doxorubicin exerted higher antitumor activity than monotherapy. In addition, we humanized the Ab27 sequence by the complementarity-determining region (CDR) grafting method. The humanized antibody Ab27-hz9 had reduced immunogenicity but exhibited target recognition and antitumor activity comparable with those of Ab27. Both Ab27 and Ab27-hz9 efficiently targeted tumor cells expressing TM4SF5 in vivo. These observations strongly support the further development of Ab27-hz9 as a novel therapeutic agent against liver and colorectal cancers.

TM4SF5-mediated liver malignancy involves NK cell exhaustion-like phenotypes

Aberrant extracellular matrix and immune cell alterations within the tumor microenvironment promote the pathological progression of liver carcinogenesis. Although transmembrane 4 L six family member 5 (TM4SF5) is involved in liver fibrosis and cancer, its mechanism avoiding immune surveillance during carcinogenesis remains unknown. We investigated how TM4SF5-mediated signaling caused immune evasion using in vitro primary cells and in vivo liver tissues from genetic or chemically induced mouse models. TM4SF5-transgenic and diethylnitrosamine (DEN)-induced liver cancer mouse models exhibited fibrotic and cancerous livers, respectively, with enhanced TM4SF5, pY⁷⁰⁵STAT3, collagen I, and laminin γ2 levels. These TM4SF5-mediated effects were abolished by TM4SF5 inhibitor, 4'-(p-toluenesulfonylamido)-4-hydroxychalcone (TSAHC). TM4SF5-dependent tumorigenesis involved natural killer (NK) cell exhaustion-like phenotypes including the reduction of NK cell number or function, which were blocked with TSAHC treatment. TM4SF5 expression in cancer cells downregulated stimulatory ligands and receptors for NK cell cytotoxicity, including SLAMF6, SLAMF7, MICA/B, and others. TM4SF5 suppression or inhibition reduced STAT3 signaling activity and recovered the receptor levels and NK cell surveillance, leading to reduced fibrotic and cancerous phenotypes, and longer survival. Altogether, these findings suggest that TM4SF5-mediated STAT3 activity for extracellular matrix modulation is involved in the progression of liver disease to HCC and that TM4SF5 appears to suppress NK cells during liver carcinogenesis.

A convergent synthetic platform for dual anticancer drugs functionalized by reduced graphene nanocomposite delivery for hepatocellular cancer

Hepatocellular carcinoma (HCC) is widespread cancer with a high degree of morbidity and mortality in individuals worldwide and a serious concern for its resistance to present chemotherapy drugs. In this investigation, the combination of cisplatin (CPT) and metformin (MET) to kill the HepG2 and caco-2 cells was developed into a new pH-responding magnetic nanocomposite based on reduced graphene oxide. Polyhydroxyethyl methacrylic (PHEA) was then linked employing grafting from approach to the reduced graphene oxide by ATRP polymerization (Fe3O4@rGO-G-PSEA). FT-IR, SEM, XRD, DLS, and TGA analyses evaluated physicochemical characteristics of the nanocomposite. In addition, the cellular uptake property of the nanocomposites was examined by the HepG2 cells. The outcomes of cell viability results indicate that the nanoparticles loaded with MET&CPT showed the lowest concentration rate of HepG2 and Caco-2 cells compared to the drug-loaded single nanocomposite groups and free drugs. The histological analysis has demonstrated relatively safe and does not produce different stress such as swelling and inflammation of the mice organs. Our results show the enhancement in cytotoxicity in HepG2 and Cocoa-2 cells by MET and CPT graphene oxide-based nanocomposite by promoting apoptotic response. Moreover, Fe3O4@rGO-G-PSEA showed potent in vivo antitumor efficacy but showed no adverse toxicity to normal tissues. Together, this study can provide insight into how surface embellishment may tune these nanocomposites' tumor specificity and provide the basis for developing anticancer efficacy.

TM4SF5-dependent crosstalk between hepatocytes and macrophages to reprogram the inflammatory environment

Chronic injury to hepatocytes results in inflammation, steatohepatitis, fibrosis, and nonalcoholic fatty liver disease (NAFLD). The tetraspanin TM4SF5 is implicated in fibrosis and cancer. We investigate the role of TM4SF5 in communication between hepatocytes and macrophages (MΦs) and its possible influence on the inflammatory microenvironment that may lead to NAFLD. TM4SF5 induction in differentiated MΦs promotes glucose uptake, glycolysis, and glucose sensitivity, leading to M1-type MΦ activation. Activated M1-type MΦs secrete pro-inflammatory interleukin-6 (IL-6), which induces the secretion of CCL20 and CXCL10 from TM4SF5-positive hepatocytes. Although TM4SF5-dependent secretion of these chemokines enhances glycolysis in M0 MΦs, further chronic exposure reprograms MΦs for an increase in the proportion of M2-type MΦs in the population, which may support diet- and chemical-induced NAFLD progression. We suggest that TM4SF5 expression in MΦs and hepatocytes is critically involved in modulating the inflammatory environment during NAFLD progression.

Fully human recombinant antibodies against EphA2 from a multi-tumor patient immune library suitable for tumor-targeted therapy

Enhanced EphA2 expression is observed in a variety of epithelial-derived malignancies and is an important target for anti-tumor therapy. Currently, Therapeutic monoclonal antibodies against immune checkpoints have shown good efficacy for tumor treatment. In this study, we constructed an immune single-chain fragment variable (scFv) library using peripheral blood mononuclear cells (PBMCs) from 200 patients with a variety of malignant tumors. High affinity scFvs against EphA2 can be easily screened from the immune library using phage display technology. Anti-EphA2 scFvs can be modified into any form of recombinant antibody, including scFv-Fc and full-length IgG1 antibodies, and the recombinant antibody affinity was improved following modification. Among the modified anti-EphA2 antibodies the affinity of 77-IgG1 was significantly increased, reaching a pmol affinity level (10⁻¹²). We further demonstrated the binding activity of recombinant antibodies to the EphA2 protein, tumor cells, and tumor tissues using macromolecular interaction techniques, flow cytometry and immunohistochemistry. Most importantly, both the constructed scFvs-Fc, as well as the IgG1 antibodies against EphA2 were able to inhibit the growth of tumor cells to some extent. These results suggest that the immune libraries from patients with malignant tumors are more likely to screen for antibodies with high affinity and therapeutic effect. The constructed fully human scFv immune library has broad application prospects for specific antibody screening. The screened scFv-Fc and IgG1 antibodies against EphA2 can be used for the further study of tumor immunotherapy.

TMEM52B suppression promotes cancer cell survival and invasion through modulating E-cadherin stability and EGFR activity

Background

TMEM52B is a novel gene broadly expressed in a variety of normal human tissues. However, the biological function of TMEM52B expression in cancer is largely unknown.

Methods

The effects of TMEM52B on tumor growth and metastasis were investigated in vitro and in vivo, and the underlying biological and molecular mechanisms involved in this process were evaluated. Clinical datasets from KmPlotter and The Cancer Genome Atlas (TCGA) were analyzed in relation to TMEM52B expression and function.

Results

Suppression of TMEM52B in colon cancer cells promoted cancer cell epithelial-mesenchymal transition (EMT), invasion, and survival in vitro. Similarly, in vivo studies showed increased tumor growth and circulating tumor cell survival (early metastasis). ERK1/2, JNK, and AKT signaling pathways were involved in TMEM52B suppression-induced invasiveness and cell survival. TMEM52B suppression promoted activation and internalization of epidermal growth factor receptor (EGFR) with enhanced downstream signaling activity, leading to enhanced cell survival and invasion. In addition, TMEM52B suppression reduced E-cadherin stability, likely due to a reduced association between it and E-cadherin, which led to enhanced β-catenin transcriptional activity. Concomitantly, TMEM52B suppression promoted generation of soluble E-cadherin fragments, contributing to the activation of EGFR. Clinical data showed that high TMEM52B expression correlated with increased patient survival in multiple types of cancer, including breast, lung, kidney, and rectal cancers, and suggested a correlation between TMEM52B and E-cadherin.

Conclusions

These findings suggest that TMEM52B is a novel modulator of the interplay between E-cadherin and EGFR. It is possible that TMEM52B functions as a tumor-suppressor that could potentially be used as a novel prognostic marker for cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01828-7.

Metastatic behavior analyses of tetraspanin TM4SF5-expressing spheres in three-dimensional (3D) cell culture environment

Cancer metastasis involves diverse cellular functions via bidirectional communications between intracellular and extracellular spaces. To achieve development of the anti-metastatic drugs, one needs to consider the efficacy and mode of action (MOA) of the drug candidates to block the metastatic potentials of cancerous cells. Rather than under two-dimensional environment, investigation of the metastatic potentials under three-dimensional environment would be much pharmaceutically beneficent, since it can mimic the in vivo tumor lesions in cancer patients, leading to allowance of drug candidates analyzed in the 3D culture systems to lower failure rates during the anti-metastatic drug development. Here we have reviewed on the analyses of metastatic potentials of certain cancer models in 3D culture systems surrounded with extracellular matrix proteins, which could be supported by TM4SF5- and/or EMT-mediated actions. We particularly focused the initial events of the cancer metastasis, such as invasive outgrowth and dissemination from the cancer cell masses, spheroids, embedded in the 3D gel culture systems. This review summarizes the significance of tetraspanin TM4SF5 and Snail1 that are related to EMT in the metastatic potentials explored in the 3D gel systems.

Translational Considerations to Improve Response and Overcome Therapy Resistance in Immunotherapy for Hepatocellular Carcinoma

Over the last decade, progress in systemic therapies significantly improved the outcome of primary liver cancer. More recently, precision oncological and immunotherapeutic approaches became the focus of intense scientific and clinical research. Herein, preclinical studies showed promising results with high response rates and improvement of overall survival. However, results of phase III clinical trials revealed that only a subfraction of hepatocellular carcinoma (HCC) patients respond to therapy and display only moderate objective response rates. Further, predictive molecular characteristics are largely missing. In consequence, suitable trial design has emerged as a crucial factor for the success of a novel compound. In addition, increasing knowledge from translational studies indicate the importance of targeting the tumor immune environment to overcome resistance to immunotherapy. Thus, combination of different immunotherapies with other treatment modalities including antibodies, tyrosine kinase inhibitors, or local therapies is highly promising. However, the mechanisms of failure to respond to immunotherapy in liver cancer are still not fully understood and the modulation of the immune system and cellular tumor composition is particularly relevant in this context. Altogether, it is increasingly clear that tailoring of immunotherapy and individualized approaches are required to improve efficacy and patient outcome in liver cancer. This review provides an overview of the current knowledge as well as translational considerations to overcome therapy resistance in immunotherapy of primary liver cancer.

A promising cancer diagnosis and treatment strategy: targeted cancer therapy and imaging based on antibody fragment

With the arrival of the precision medicine and personalized treatment era, targeted therapy that improves efficacy and reduces side effects has become the mainstream approach of cancer treatment. Antibody fragments that further enhance penetration and retain the most critical antigen-specific binding functions are considered the focus of research targeting cancer imaging and therapy. Thanks to the superior penetration and rapid blood clearance of antibody fragments, antibody fragment-based imaging agents enable efficient and sensitive imaging of tumour sites. In tumour-targeted therapy, antibody fragments can directly inhibit tumour proliferation and growth, serve as an ideal carrier for delivery of anti-tumour drugs, or manipulate the immune system to eliminate tumour cells. In this review, the excellent physicochemical properties and the basic structure of antibody fragments are expressly depicted depicted, the progress of antibody fragments in cancer therapy and imaging are thoroughly summarized, and the future development of antibody fragments is predicted.

Targeting TM4SF5 with anti-TM4SF5 monoclonal antibody suppresses the growth and motility of human pancreatic cancer cells

Pancreatic cancer is one of the most lethal cancers. Transmembrane 4 superfamily member 5 protein (TM4SF5) is one of the candidate molecular targets used for the prevention and treatment of TM4SF5-expressing cancers, including hepatocellular carcinoma, colon cancer and pancreatic cancer. Recently, a previous study reported the preventive effects of a peptide vaccine, which targeted TM4SF5, in a mouse pancreatic cancer model. The present study investigated the implication of TM4SF5 and the suppressive effect of anti-human TM4SF5 monoclonal antibody (anti-hTM4SF5 antibody) in human pancreatic cancer cell lines in vitro. Treatment with anti-hTM4SF5 antibody reduced cell viability, modulated the expression of EMT markers Vimentin and E-cadherin, and decreased cell motility in human pancreatic cancer cells that endogenously expressed TM4SF5. When TM4SF5 was exogenously overexpressed in the TM4SF5-negative cell line, the cells indicated increased cell viability and motility compared with control cells, and the phenotype was reversed by anti-hTM4SF5 antibody treatment. Therefore, the results of the current study demonstrated that the high expression of TM4SF5 is a tumorigenic factor in human pancreatic cells and anti-hTM4SF5 antibody treatment exhibits a suppressive effect in TM4SF5-expressing pancreatic cancer cells.

Anti-cancer activity of the novel 2-hydroxydiarylamide derivatives IMD-0354 and KRT1853 through suppression of cancer cell invasion, proliferation, and survival mediated by TMPRSS4

Elevated expression of transmembrane serine protease 4 (TMPRSS4) correlates with poor prognosis in non-small cell lung cancer, gastric cancer, colorectal cancer, prostate cancer, and other cancer patients. Previously, we demonstrated that TMPRSS4 mediates tumor cell invasion, migration, proliferation, and metastasis. In addition, we reported novel 2-hydroxydiarylamide derivatives, IMD-0354 and KRT1853, as TMPRSS4 serine protease inhibitors. Here, we further evaluated the effects of the representative derivatives on TMPRSS4-mediated cellular function and signaling. IMD-0354 and KRT1853 inhibited cancer cell invasion, migration, and proliferation in TMPRSS4-expressing prostate, colon, and lung cancer cells. Both compounds suppressed TMPRSS4-mediated induction of Sp1/3, AP-1, and NF-κB transcription factors. Furthermore, TMPRSS4 promoted cancer cell survival and drug resistance, and both compounds enhanced anoikis sensitivity as well as reduced bcl-2 and survivin levels. Importantly, KRT1853 efficiently reduced tumor growth in prostate and colon cancer xenograft models. These results strongly recommend KRT1853 for further development as a novel anti-cancer agent.

Transmembrane 4 L Six Family Member 5 Senses Arginine for mTORC1 Signaling

The mechanistic target of rapamycin complex (mTORC1) is a signaling hub on the lysosome surface, responding to lysosomal amino acids. Although arginine is metabolically important, the physiological arginine sensor that activates mTOR remains unclear. Here, we show that transmembrane 4 L six family member 5 (TM4SF5) translocates from plasma membrane to lysosome upon arginine sufficiency and senses arginine, culminating in mTORC1/S6K1 activation. TM4SF5 bound active mTOR upon arginine sufficiency and constitutively bound amino acid transporter SLC38A9. TM4SF5 binding to the cytosolic arginine sensor Castor1 decreased upon arginine sufficiency, thus allowing TM4SF5-mediated sensing of metabolic amino acids. TM4SF5 directly bound free L-arginine via its extracellular loop possibly for the efflux, being supported by mutant study and homology and molecular docking modeling. Therefore, we propose that lysosomal TM4SF5 senses and enables arginine efflux for mTORC1/S6K1 activation, and arginine-auxotroph in hepatocellular carcinoma may be targeted by blocking the arginine sensing using anti-TM4SF5 reagents.

Epigenetic suppression of E-cadherin expression by Snail2 during the metastasis of colorectal cancer

Background

The transcription factor Snail2 is a repressor of E-cadherin expression during carcinogenesis; however, the specific mechanisms involved in this process in human colorectal cancer (CRC) remain largely unknown.

Method

We checked the expression of Snail2 in several clinical CRC specimens. Then, we established Snail2-overexpressing and knockdown cell lines to determine the function of Snail2 during EMT and metastasis processes in CRC. In addition, we used luciferase reporter assay to explore how Snail2 inhibits the expression of E-cadherin and induces EMT.

Results

We found that the expression of Snail2 was higher in clinical specimens of colorectal cancer (CRC) compared to non-cancerous tissues. Overexpression of Snail2 induced migration and metastatic properties in CRC cells in vitro and in vivo. Furthermore, overexpression of Snail2 promoted the occurrence of the epithelial–mesenchymal transition (EMT), downregulating the expression of E-cadherin and upregulating that of vimentin. Specifically, Snail2 could interact with HDAC6 and then recruited HDAC6 and PRC2 to the promoter of E-cadherin and thus inhibited the expression of E-cadherin, promoting EMT and inducing invasion and metastasis of CRC.

Conclusion

Our study reveals that Snail2 might epigenetically suppress the expression of E-cadherin during CRC metastasis.

Peroxiredoxin 5 promotes the epithelial-mesenchymal transition in colon cancer

Globally, colorectal cancer (CRC) is common cause of cancer-related deaths. The high mortality rate of patients with colon cancer is due to cancer cell invasion and metastasis. Initiation of the epithelial-to-mesenchymal transition (EMT) is essential for the tumorigenesis. Peroxiredoinxs (PRX1-6) have been reported to be overexpressed in various tumor tissues, and involved to be responsible for tumor progression. However, the exact role of PRX5 in colon cancer remains to be investigated enhancing proliferation and promoting EMT properties. In this study, we constructed stably overexpressing PRX5 and suppressed PRX5 expression in CRC cells. Our results revealed that PRX5 overexpression significantly enhanced CRC cell proliferation, migration, and invasion. On the other hand, PRX5 suppression markedly inhibited these EMT properties. PRX5 was also demonstrated to regulate the expression of two hallmark EMT proteins, E-cadherin and Vimentin, and the EMT-inducing transcription factors, Snail and Slug. Moreover, in the xenograft mouse model, showed that PRX5 overexpression enhances tumor growth of CRC cells. Thus, our findings first provide evidence in CRC that PRX5 promotes EMT properties by inducing the expression of EMT-inducing transcription factors. Therefore, PRX5 can be used as a predictive biomarker and serves as a putative therapeutic target for the development of clinical treatments for human CRC.