Doxorubicin-induced epithelial–mesenchymal transition through SEMA 4A in hepatocellular carcinoma

Semaphorin4A promotes lung cancer by activation of NF-κB pathway mediated by PlexinB1

Background

Lung cancer (LC) is the most prevalent cancer with a poor prognosis. Semaphorin4A (Sema4A) is important in many physiological and pathological processes. This study aimed to explore the role and mechanism of Sema4A in LC.

Methods

Firstly, Sema4A expression was analyzed by the available dataset and detected in human normal bronchial epithelial cell line (HBE) and LC cell line (NCI-H460). Then, LC cells were transfected with Sema4A siRNA, and the cells were stimulated by PlexinB1, PlexinB2, PlexinD1 blocking antibodies, IgG antibody, BAY 11-7082 (an inhibitor for NF-κB pathway) and Sema4A-Fc protein, alone or in combination. After transfection, PlexinB1 mRNA expression was analyzed. Next, the biological functions, including proliferative, migratory, invasive abilities and viability of the cells were detected by colony formation, scratch, Transwell and MTT assays, respectively. NF-κB, Stat3 and MAPK protein expressions were determined by western blot. Furthermore, the secretion of IL-6 in LC cells was tested by ELISA.

Results

Sema4A was highly expressed in LC tissues and cells, could activate the NF-κB pathway and upregulate PlexinB1 mRNA expression. Furthermore, we observed that Sema4A knockdown suppressed the biological functions of NCI-H460 cells, while Sema4A-Fc protein reversed the situation. However, Sema4A-induced biological functions and activation in the NF-κB pathway were inhibited by PlexinB1 blocking antibody. Consistently, Sema4A promoted IL-6 production, which was down-regulated by PlexinB1 blocking antibody and BAY 11-7082.

Conclusions

Sema4A may facilitate LC development via the activation of the NF-κB pathway mediated by PlexinB1, suggesting that Sema4A would be a novel therapeutic target for LC treatment.

Doxorubicin and other anthracyclines in cancers: Activity, chemoresistance and its overcoming

Anthracyclines have been important and effective treatments against a number of cancers since their discovery. However, their use in therapy has been complicated by severe side effects and toxicity that occur during or after treatment, including cardiotoxicity. The mode of action of anthracyclines is complex, with several mechanisms proposed. It is possible that their high toxicity is due to the large set of processes involved in anthracycline action. The development of resistance is a major barrier to successful treatment when using anthracyclines. This resistance is based on a series of mechanisms that have been studied and addressed in recent years. This work provides an overview of the anthracyclines used in cancer therapy. It discusses their mechanisms of activity, toxicity, and chemoresistance, as well as the approaches used to improve their activity, decrease their toxicity, and overcome resistance.

Emerging roles and mechanisms of semaphorins activity in cancer

Semaphorins are regulatory molecules that are linked to the modulation of several cancer processes, such as angiogenesis, cancer cell invasiveness and metastasis, tumor growth, as well as cancer cell survival. Semaphorin (SEMA) activity depends on the cancer histotypes and their particularities. In broad terms, the effects of SEMAs result from their interaction with specific receptors/co-receptors - Plexins, Neuropilins and Integrins - and the subsequent effects upon the downstream effectors (e.g. PI3K/AKT, MAPK/ERK). The present article serves as an integrative review work, discussing the broad implications of semaphorins in cancer, focusing on cell proliferation/survival, angiogenesis, invasion, metastasis, stemness, and chemo-resistance/response whilst highlighting their heterogeneity as a family. Herein, we emphasized that semaphorins are largely implicated in cancer progression, interacting with the tumor microenvironment components. Whilst some SEMAs (e.g. SEMA3A, SEMA3B) function widely as tumor suppressors, others (e.g. SEMA3C) act as pro-tumor semaphorins. The differences observed in terms of the biological structure of SEMAs and the particularities of each cancer histotypes require that each semaphorin be viewed as a unique entity, and its roles must be researched accordingly. A more in-depth and comprehensive view of the molecular mechanisms that promote and sustain the malignant behavior of cancer cells is of utmost importance.

Value of biomarkers in epithelial-mesenchymal transition models of liver cancer under different interventions: a meta-analysis

Aim: A meta-analysis was conducted to evaluate the effectiveness of crucial biomarkers in HepG2 cells during epithelial-mesenchymal transformation induced by multiple interventions. Methods: PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, Wan Fang Data and VIP databases were systematically searched from inception to 14 June 2020, by two independent reviewers. Results: A total of 58 studies were included in the meta-analysis. E-cadherin, N-cadherin and vimentin performed well under medicinal interventions. E-cadherin worked well under genetic interventions. E-cadherin and N-cadherin also performed significantly well under tumor microenvironment interventions. Under ncRNA interventions, the expression of E-cadherin significantly changed. Conclusion: Different sets of biomarkers should be selected under various interventions based on their performance.

Class IV semaphorins in disease pathogenesis

Semaphorins are a large family of secreted and/or transmembrane proteins, originally identified as proteins that function in axon guidance during neuronal development. However, semaphorins play crucial roles in other physiological and pathological processes, including immune responses, angiogenesis, maintenance of tissue homeostasis, and cancer progression. Class IV semaphorins may be present as transmembrane and soluble forms and are implicated in the pathogenesis of various diseases. This review discusses recent progress on the roles of class IV semaphorins determined by clinical and experimental pathology studies.

The involvement of epithelial-to-mesenchymal transition in doxorubicin resistance: Possible molecular targets

Considering the fact that cancer cells can switch among various molecular pathways and mechanisms to ensure their progression, chemotherapy is no longer effective enough in cancer therapy. As an anti-tumor agent, doxorubicin (DOX) is derived from Streptomyces peucetius and can induce cytotoxicity by binding to topoisomerase enzymes to suppress DNA replication, leading to apoptosis and cell cycle arrest. However, efficacy of DOX in suppressing cancer progression is restricted by development of drug resistance. Cancer cells elevate their metastasis in triggering DOX resistance. The epithelial-to-mesenchymal transition (EMT) mechanism participates in transforming epithelial cells into mesenchymal cells that have fibroblast-like features. The EMT diminishes intercellular adhesion and enhances migration of cells that are necessary for carcinogenesis. Various oncogenic molecular pathways stimulate EMT in cancer. EMT can induce DOX resistance, and in this way, upstream mediators such as ZEB proteins, microRNAs, Twist1 and TGF-β play a significant role. Identification of molecular pathways involved in EMT regulation and DOX resistance has resulted in using gene therapy such as microRNA transfection and siRNA in overcoming chemoresistance. Furthermore, curcumin and formononetin, owing to their cytotoxicity against cancer cells, can suppress EMT in mediating DOX sensitivity. For promoting efficacy in DOX sensitivity, nanoparticles have been developed for boosting ability in EMT inhibition.

MicroRNA-520c-3p Modulates Doxorubicin-Chemosensitivity in HepG2 Cells

BACKGROUND

Doxorubicin (DOX) is one of the most common drugs used in cancer therapy, including Hepatocellular Carcinoma (HCC). Drug resistance is one of chemotherapy's significant problems. Emerging studies have shown that microRNAs (miRNAs) could participate in regulating this mechanism. Nevertheless, the impact of miRNAs on HCC chemoresistance is still enigmatic.

OBJECTIVE

Investigating the role of microRNA-520c-3p (miR-520c-3p) in the enhancement of the anti-tumor effect of DOX against HepG2 cells.

METHODS

Expression profile for liver-related miRNAs (384 miRNAs) has been analyzed on HepG2 cells treated with DOX using qRT-PCR. miR-520c-3p, the most deregulated miRNA, was selected for combination treatment with DOX. The expression level for LEF1, CDK2, CDH1, VIM, Mcl-1 and p53 was evaluated in miR-520c-3p transfected cells. Cell viability, colony formation, wound healing as well as apoptosis assays have been demonstrated. Furthermore, Mcl-1 protein level was measured using the western blot technique.

RESULTS

The present data indicated that miR-520c-3p overexpression could render HepG2 cells chemo-sensitive to DOX through enhancing its suppressive effects on proliferation, migration, and induction of apoptosis. The suppressive effect of miR-520c-3p involved altering the expression levels of some key regulators of cell cycle, proliferation, migration and apoptosis, including LEF1, CDK2, CDH1, VIM, Mcl-1 and p53. Interestingly, Mcl-1 was found to be one of the potential targets of miR-520c-3p, and its protein expression level was down-regulated upon miR-520c-3p overexpression.

CONCLUSION

Our data referred to the tumor suppressor function of miR-520c-3p that could modulate the chemosensitivity of HepG2 cells towards DOX treatment, providing a promising therapeutic strategy in HCC.

Semaphorin 4A restricts tumor progression by inhibiting angiogenesis of oral squamous cell carcinoma cells

OBJECTIVE

To investigate the effects of Semaphorin 4A (Sema4A) on the angiogenesis, migration and invasion of oral squamous cell carcinoma (OSCC) cells.

METHODS

Sema4A expression in OSCC patients was detected by Immunohistochemistry, and its relationship with clinicopathological features and prognosis of patients was analyzed. The mRNA and protein expression of Sema4A in primary human oral keratinocytes (HOKs) and OSCC cells (SCC-25, HSC-3, CAL-27) were determined by Western blotting and qRT-PCR. After HOKs, HSC-3 cells and SCC-25 cells transfected with Control/Sema4A CRISPR activation plasmid, the migration and invasion abilities were detected by Wound healing and Transwell invasion. Tube formation assay was also performed on endothelial cells and the contents of VEGF and bFGF were quantified using qRT-PCR and ELISA.

RESULTS

Cytoplasmic Sema4A expression was related to T classification, clinical stage and nodal metastasis of OSCC patients. Patients with low cytoplasmic Sema4A expression showed the higher microvessel density (MVD) and the poorer prognosis in OSCC. Compared with HOK, OSCC cells (SCC-25, HSC-3, CAL-27) declined apparently in Sema4A expression, which was much more significant in metastatic HSC-3 and SCC-25 cells. After HOKs, HSC-3 cells and SCC-25 cells transfected with Sema4A over-expression plasmid, the invasion and migration abilities were decreased. Besides, overexpression of Sema4A could significantly inhibit the tube formation of HUVEC induced by OSCC cells with reductions of angiogenic factors (VEGF and bFGF).

CONCLUSION

Over-expression of Sema4A could restrict tumor progression through inhibiting the angiogenesis, invasion and migration of OSCC cells.

Semaphorin 4A, 4C, and 4D: Function comparison in the autoimmunity, allergy, and cancer

Semaphorins are a group of proteins that are divided into eight subclasses and identified by a conserved Sema domain on their carboxyl terminus. Sema4A, 4C, and 4D are the members of the fourth class of semaphorin family, which are known as membrane semaphorins; however, these molecules can be altered to soluble semaphorins by proteolytic cleavage. Semaphorins have various roles in the immune, nervous, and metabolic systems. In the immune system, these molecules contribute to the formation of cellular, humoral, and innate immune responses, such as inflammation, leukocyte migration, immunological synapse formation, and germinal center events. Given the diverse roles of semaphorins in the immune system, in this review, we have tried to give a comprehensive look at the role of these molecules in autoimmunity, allergy, and cancer. Sema4D and 4A seem to play a critical role in the pathogenesis of some autoimmune diseases, such as multiple sclerosis. In contrast, it has been shown that Sema4A and 4C have beneficial effects on allergies, and their absence can exacerbate the severity of the disease. In the case of cancer, an increase in all three of these molecules has been reported. Sema4D and 4C can contribute to tumor progression in human patients or experimental models, while the role of Sema4A has not yet been fully understood. In conclusion, semaphorins seem to be a favorable therapeutic target for autoimmune diseases and allergies. However, in cancer, studies have not yet been able to identify the exact role of semaphorins, and further studies are needed.

Low‑intensity ultrasound enhances the antitumor effects of doxorubicin on hepatocellular carcinoma cells through the ROS‑miR‑21‑PTEN axis

Hepatocellular carcinoma (HCC) is a type of liver cancer and is a leading cause of cancer-associated mortality. In China, ~466,000 patients are diagnosed with HCC and it is responsible for ~422,000 cases of mortality each year. Surgery is the most effective treatment available; however it is only suitable for patients with early-stage HCC. Chemotherapy has been confirmed as a necessary treatment for patients with advanced HCC, although drug resistance may limit its clinical outcome. Low intensity ultrasound (LIUS) represents a novel therapeutic approach to treat patients with HCC; however, its underlying molecular mechanism remains unclear. In the present study, cell viability, apoptosis and reactive oxygen species (ROS) generation were determined via Cell Counting Kit-8, flow cytometry and 2′,7′-dichlorofluorescein diacetate assays, respectively. The expression of miRNA in HCC cells following exposure to LIUS and doxorubicin (Dox) was analyzed using a microarray and reverse transcription-quantitative polymerase chain reaction analysis. It was revealed treatment with LIUS in combination with Dox was able to induce apoptosis of Huh7 cells, increasing the intracellular levels of reactive oxygen species (ROS) and malondialdehyde. Glutathione peroxidase and superoxide dismutase 1 are ROS-scavenging enzymes, which serve important roles in the oxidative balance, preventing oxidative stress. The protein expression levels of these two enzymes were significantly decreased following treatment with LIUS combined with Dox. The present results suggested that LIUS may decrease Dox resistance in HCC cells and that LIUS may be combined with chemotherapy to treat HCC. By performing microarray analysis, the expression levels of microRNA-21 (miR-21) were decreased following treatment with LIUS combined with Dox. Functional experiments showed that knockdown of miR-21 enhanced the antitumor activity of Dox, whereas overexpression of miR-21 reversed these effects. Phosphatase and tensin homolog (PTEN), a well-known tumor suppressor, was revealed to be a direct target of miR-21, and its translation was suppressed by miR-21. Finally, it was determined that combined treatment of LIUS and Dox induced anticancer effects by blocking the activation of the AKT/mTOR pathway, as demonstrated by the downregulation of phosphorylated (p-)AKT and p-mTOR; N-acetylcysteine, a general ROS inhibitor reversed the suppressive effects on the AKT/mTOR pathway mediated by LIUS and Dox. Collectively, the present results suggested that LIUS increased cell sensitivity to Dox via the ROS/miR-21/PTEN pathway. Chemotherapy combined with LIUS may represent a novel effective therapeutic strategy to treat patients with advanced HCC.

Semaphorins as Regulators of Phenotypic Plasticity and Functional Reprogramming of Cancer Cells

Semaphorins, initially found as neuronal guidance cues in embryo development, are now appreciated as major regulators of tissue morphogenesis and homeostasis, as well as of cancer progression. In fact, semaphorin signals have a profound impact on cell morphology, which has been commonly associated with the ability to regulate monomeric GTPases, cell-substrate adhesion, and cytoskeletal dynamics. Recently, however, several reports have indicated a novel and additional function of diverse semaphorins in the regulation of gene expression and cell phenotype plasticity. In this review article, we discuss these novel findings, focusing on the role of semaphorin signals in the regulation of bi-directional epithelial-mesenchymal transitions, stem cell properties, and drug resistance, which greatly contribute to the pathogenesis of cancer.

Sema4A Responds to Hypoxia and Is Involved in Breast Cancer Progression

Semaphorin4A (Sema4A) is a family member of semaphorins expressed in immune cells and is also related with disease progression of tumor disease. In this study, we investigate the expression and pathological role of Sema4A in breast cancer (BCa). Our data showed that the expression of Sema4A increased in the tissues and serum of BCa patients when compared with normal controls. The expression of Sema4A in BCa cells could be induced by hypoxic treatment, whereas silencing hypoxia-inducible factor (HIF)-1α could attenuate the above induced. Furthermore, chromatin immunoprecipitation (ChIP) analysis demonstrated that HIF-1α could regulate the expression of Sema4A through directly binding to the promoter of Sema4A gene, whose enrichment could be further enhanced by hypoxic stimulation. In addition, silencing Sema4A could inhibit the proliferation, vascular endothelial growth factor (VEGF) production and the phosphorylation of Akt, extracellular signal-regulated kinase (ERK)1/2 mitogen-activated protein kinase (MAPK) and signal transduction and activator of transcription (STAT)3, but induce apoptosis of BCa cells in the presence of hypoxia. In contrast, recombinant human Sema4A treatment showed the opposite effects. Taken together, these results suggest that Sema4A could promote progression of BCa in the presence of hypoxia and it may hold potential for treatment target for BCa.

Blocking epithelial-to-mesenchymal transition in glioblastoma with a sextet of repurposed drugs: the EIS regimen

This paper outlines a treatment protocol to run alongside of standard current treatment of glioblastoma- resection, temozolomide and radiation. The epithelial to mesenchymal transition (EMT) inhibiting sextet, EIS Regimen, uses the ancillary attributes of six older medicines to impede EMT during glioblastoma. EMT is an actively motile, therapy-resisting, low proliferation, transient state that is an integral feature of cancers’ lethality generally and of glioblastoma specifically. It is believed to be during the EMT state that glioblastoma’s centrifugal migration occurs. EMT is also a feature of untreated glioblastoma but is enhanced by chemotherapy, by radiation and by surgical trauma. EIS Regimen uses the antifungal drug itraconazole to block Hedgehog signaling, the antidiabetes drug metformin to block AMP kinase (AMPK), the analgesic drug naproxen to block Rac1, the anti-fibrosis drug pirfenidone to block transforming growth factor-beta (TGF-beta), the psychiatric drug quetiapine to block receptor activator NFkB ligand (RANKL) and the antibiotic rifampin to block Wnt- all by their previously established ancillary attributes. All these systems have been identified as triggers of EMT and worthy targets to inhibit. The EIS Regimen drugs have a good safety profile when used individually. They are not expected to have any new side effects when combined. Further studies of the EIS Regimen are needed.