Activation of AMPKα mediates additive effects of solamargine and metformin on suppressing MUC1 expression in castration-resistant prostate cancer cells

Solamargine improves the therapeutic efficacy of anti-PD-L1 in lung adenocarcinoma by inhibiting STAT1 activation

OBJECTIVE

The effect of solamargine on lung adenocarcinoma and its effect on STAT1 signaling pathway mediated immune escape were studied through network pharmacology and in vitro and in vivo experiments.

METHODS

The solamargine targets were screened using the TCMSP and the LUAD targets were screened using the GeneCard, OMIM, PharmGkb, TTD and DrugBank databases. PPI network analysis and target prediction were performed using GO and KEGG. Colony formation assay, EDU staining, wound healing, transwell assay, Hoechst and flow cytometry were used to detect the effects of solamargine on the proliferation, migration and apoptosis of LUAD. Western blotting (WB) and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to detect P-STAT1 and PD-L1 expression. And immunofluorescence was used to detect P-STAT1 expression. In vivo experiments, C57BL/6 mice were divided into control group, low concentration group, high concentration group, positive control group and combination group. Every other day, following seven consecutive doses, the size of the tumor was assessed. Finally, the expressions of P-STAT1, STAT1, PD-L1 and apoptosis index proteins were detected by WB.

RESULTS

The anti-LUAD effect of solamargine was found by wound healing, colony formation assay, transwell assay, hoechst and EdU staining. The results of network pharmacological analysis showed that solamargine could suppress STAT1 expression level. Further enrichment assay of STAT1 showed that STAT1 was associated with immune-related pathways. In addition, molecular signal analysis by WB and RT-qPCR indicated that solamargine could reduce the expression levels of P-STAT1 and PD-L1 in a concentration-dependent manner. According to the results of in vivo assays, combination of solamargine and immune checkpoint inhibitors (ICIs) durvalumab could significantly inhibit the growth of Lewis transplanted tumors in C57BL/6 mice, and no toxic side effect was recoded.

CONCLUSION

These results indicated that solamargine could inhibit the proliferation and promote the apoptosis of LUAD. It also could reduce the expression level of P-STAT1 protein and inhibit the expression level of PD-L1. At the same time, the combination with the ICIs can better block the expression of PD-L1 in cells, thereby inhibiting the immune escape pathway of tumor cells and achieving anti-tumor effects. This study proposed a novel combined therapeutic approach, involving the inhibition of STAT1 by solamargine in conjunction with ICIs.

Metformin: A Dual-Role Player in Cancer Treatment and Prevention

Cancer continues to pose a significant global health challenge, as evidenced by the increasing incidence rates and high mortality rates, despite the advancements made in chemotherapy. The emergence of chemoresistance further complicates the effectiveness of treatment. However, there is growing interest in the potential of metformin, a commonly prescribed drug for type 2 diabetes mellitus (T2DM), as an adjuvant chemotherapy agent in cancer treatment. Although the precise mechanism of action of metformin in cancer therapy is not fully understood, it has been found to have pleiotropic effects, including the modulation of metabolic pathways, reduction in inflammation, and the regulation of cellular proliferation. This comprehensive review examines the anticancer properties of metformin, drawing insights from various studies conducted in vitro and in vivo, as well as from clinical trials and observational research. This review discusses the mechanisms of action involving both insulin-dependent and independent pathways, shedding light on the potential of metformin as a therapeutic agent for different types of cancer. Despite promising findings, there are challenges that need to be addressed, such as conflicting outcomes in clinical trials, considerations regarding dosing, and the development of resistance. These challenges highlight the importance of further research to fully harness the therapeutic potential of metformin in cancer treatment. The aims of this review are to provide a contemporary understanding of the role of metformin in cancer therapy and identify areas for future exploration in the pursuit of effective anticancer strategies.

Active components of Solanum nigrum and their antitumor effects: a literature review

Cancer poses a serious threat to human health and overall well-being. Conventional cancer treatments predominantly encompass surgical procedures and radiotherapy. Nevertheless, the substantial side effects and the emergence of drug resistance in patients significantly diminish their quality of life and overall prognosis. There is an acute need for innovative, efficient therapeutic agents to address these challenges. Plant-based herbal medicines and their derived compounds offer promising potential for cancer research and treatment due to their numerous advantages. Solanum nigrum (S. nigrum), a traditional Chinese medicine, finds extensive use in clinical settings. The steroidal compounds within S. nigrum, particularly steroidal alkaloids, exhibit robust antitumor properties either independently or when combined with other drugs. Many researchers have delved into unraveling the antitumor mechanisms of the active components present in S. nigrum, yielding notable progress. This literature review provides a comprehensive analysis of the research advancements concerning the active constituents of S. nigrum. Furthermore, it outlines the action mechanisms of select monomeric anticancer ingredients. Overall, the insights derived from this review offer a new perspective on the development of clinical anticancer drugs.

The Therapeutic Value of Solanum Steroidal (Glyco)Alkaloids: A 10-Year Comprehensive Review

Steroidal (glycol)alkaloids S(G)As are secondary metabolites made of a nitrogen-containing steroidal skeleton linked to a (poly)saccharide, naturally occurring in the members of the Solanaceae and Liliaceae plant families. The genus Solanum is familiar to all of us as a food source (tomato, potato, eggplant), but a few populations have also made it part of their ethnobotany for their medicinal properties. The recent development of the isolation, purification and analysis techniques have shed light on the structural diversity among the SGAs family, thus attracting scientists to investigate their various pharmacological properties. This review aims to overview the recent literature (2012-2022) on the pharmacological benefits displayed by the SGAs family. Over 17 different potential therapeutic applications (antibiotic, antiviral, anti-inflammatory, etc.) were reported over the past ten years, and this unique review analyzes each pharmacological effect independently without discrimination of either the SGA's chemical identity or their sources. A strong emphasis is placed on the discovery of their biological targets and the subsequent cellular mechanisms, discussing in vitro to in vivo biological data. The therapeutic value and the challenges of the solanum steroidal glycoalkaloid family is debated to provide new insights for future research towards clinical development.

Anticancer activity of glycoalkaloids from Solanum plants: A review

Cancer is still one of the main causes of death worldwide. For this reason, new compounds that have chemotherapeutic potential have been identified. One such group of substances is Solanaceae glycoalkaloids (GAs). They are natural compounds produced by plants widely used in traditional medicine for healing many disorders. Among others, GAs exhibit significant antitumor properties, for example, a strong inhibitory effect on cancer cell growth. This activity can result in the induction of tumor cell apoptosis, which can occur via different molecular pathways. The molecular mechanisms of the action of GAs are the subject of intensive research, as improved understanding could lead to the development of new cancer therapies. The genetic basis for the formation of neoplasms are mutations in protooncogenes, suppressors, and apoptosis-controlling and repair genes; therefore, substances with antineoplastic properties may affect the levels of their expression or the levels of their expression products. Therapeutic compounds can be applied separately or in combination with other drugs to increase the efficiency of cancer therapy; they can act on the cell through various mechanisms at different stages of carcinogenesis, inducing the process of apoptosis, blocking cell proliferation and migration, and inhibiting angiogenesis. This review summarizes the newest studies on the anticancer properties of solanine (SN), chaconine (CH), solasonine (SS), solamargine (SM), tomatine (TT) and their extracts from Solanum plants.

Solamargine Alleviates Proliferation and Metastasis of Cervical Cancer Cells by Blocking the CXCL3-Mediated Erk Signaling Pathway

Solamargine has unique antitumor efficacy in a variety of cancers. The study is to explore the role of solamargine in cervical cancer. HeLa and SiHa cells were exposed to solamargine treatment at divergent concentrations (0, 5, 10, and 20 μM). The antitumor role of solamargine in cervical cancer cells was determined by cell counting kit 8 (CCK-8), colony formation, scratch test, transwell assay, and western blot. The expression of mRNAs regulating the extracellular regulated protein kinases (Erk) pathway in solamargine-treated cells was detected by qRT-PCR. Rescue experiments were conducted to explore the effect of C-X-C motif chemokine ligand 3 (CXCL3). Following that, we inhibited Erk1/2 by PD98059 to investigate the interplay between CXCL3 and Erk pathway in solamargine-treated cells by measuring migration, invasion, and related matrix metalloproteinase (MMP) expressions. Solamargine inhibited the viability, proliferation, migration, and invasion of cervical cancer cells in a dose-dependent manner. The expression of p-Erk1/2 was downregulated by solamargine. CXCL3 overexpression abrogated the antitumor effect of solamargine on cervical cancer cells. The inhibition of the Erk signaling pathway restored the inhibiting role of solamargine which interfered with CXCL3 overexpression, in invasion, migration, and expressions of MMP-2 and MMP-9 in cervical cancer cells. Moreover, solamargine inhibited the growth of tumor in vivo xenograft model. Solamargine alleviated proliferation and metastasis of cervical cancer cells by blocking the CXCL3-mediated Erk signaling pathway.

Characteristics of clinical trials for non-small cell lung cancer therapeutic vaccines registered on ClinicalTrials.gov

Background

Even after complete surgical treatment or chemotherapy, Non-Small Cell Lung Cancer (NSCLC) patients are also at substantial risk for recurrence and spread trend. Therapeutic cancer vaccination could increase the anti-tumor immune response and prevent tumor relapse. This study aimed to assess the characteristics of NSCLC therapeutic vaccines registered on ClinicalTrials.gov.

Methods

We conducted a cross-sectional, descriptive study of clinical trials for Non-Small Cell Lung Cancer Therapeutic Vaccines Registered on ClinicalTrials.gov (https://clinicaltrials.gov/) through March 17, 2022.

Results

This study encompassed 117 registered trials included for data analysis. The number of trials was significantly correlated with a beginning year (r = 0.504, P < 0.010). Of these trials, 45.30% were completed, 12.82% were terminated, and 8.55% were withdrawn. More than half of trials (52.99%) were funded by industry, and more than half of trials (52.14%) were located in economically developed North America. Regarding study designs of these trials, 27.35% were randomized, 52.14% were single group assignment, 83.76% were without masking, 35.90% were phase 1, and more than half of the trials (56.41%) recruited less than 50 participants. The highest proportion of vaccine types was protein/peptide vaccines (41.88%). Regarding TNM staging, the highest proportion of the trials is stage III-IV (26.50%).

Conclusion

The number of clinical trials about the cancer therapeutic vaccines was sustained an increase in recent years. The main characteristic of clinical trials for NSCLC therapeutic vaccines is lack of randomized control, lack of mask, and recruiting less than 50 participants. In recent years, the protein/peptide vaccines for NSCLC active immunotherapy have been well studied.

Identification of solamargine as a cisplatin sensitizer through phenotypical screening in cisplatin-resistant NSCLC organoids

Although Cisplatin (DDP) is a widely used first-line chemotherapy medication, DDP resistance is one of the main causes of treatment failure in advanced lung cancer. Therefore, it is urgent to identify DDP sensitizers and investigate the underlying molecular mechanisms. Here we utilized DDP-resistant organoids established from tumor biopsies of patients with relapsed lung cancers. In this study, we identified Solamargine as a potential DDP sensitizer through screening a natural product library. Mechanically, Solamargine induced G0/G1-phase arrest and apoptosis in DDP-resistant lung cancer cell lines. Gene expression analysis and KEGG pathway analysis indicated that the hedgehog pathway was suppressed by Solamargine. Moreover, Gli responsive element (GRE) reporter gene assay and BODIPY-cyclopamine binding assay showed that Solamargine inhibited the hedgehog pathway via direct binding to SMO protein. Interestingly, Solamargine and DDP showed a synergetic effect in inhibiting DDP-resistant lung cancer cell lines. Taken together, our work herein revealed Solamargine as a hedgehog pathway inhibitor and DDP-sensitizer, which might provide a new direction for further treatment of advanced DDP-resistant lung cancer patients.

Solamargine Inhibits the Development of Hypopharyngeal Squamous Cell Carcinoma by Decreasing LncRNA HOXA11-As Expression

Hypopharyngeal squamous cell carcinoma (HSCC) is one of the high mortality cancers with a poor prognosis, which is driving the development of new chemotherapeutic agents. We identified the anticancer effects of a natural compound, solamargine (SM), on FaDU cells and explored its mechanism in terms of non-coding RNA. It was observed that SM inhibited the proliferation of FaDU cells with an IC₅₀ of 5.17 μM. High-throughput sequencing data revealed that lncRNA HOXA11-AS was significantly downregulated in cells co-incubated with SM. Further assays demonstrated that SM-induced downregulation of lncRNA HOXA11-AS showed important implications for apoptosis. Given the properties of HOXA11-AS as a miR-155 sponge, we further confirmed that SM upregulated the expression of miR-155 in FaDU cells. C-Myc is a transcription factor that regulates cell differentiation and apoptosis, whose mRNA is considered to be targeted by miR-155. We showed that c-Myc expression was downregulated by SM and accompanied by increased apoptosis, which was consistent with the findings of transcriptome sequencing. Furthermore, SM administration suppressed xenograft tumor growth in a xenograft mouse model in vivo. In the light of the aforementioned findings, our results suggested that SM downregulated the expression of HOXA11-AS, which in turn induces apoptosis by downregulating c-Myc in FaDU, providing evidence for the anticancer effect of SM on HSCC and uncovering the effect of SM on non-coding RNAs as, at least partly, a mechanism of action.

Role of Plant-Derived Active Constituents in Cancer Treatment and Their Mechanisms of Action

Despite significant technological advancements in conventional therapies, cancer remains one of the main causes of death worldwide. Although substantial progress has been made in the control and treatment of cancer, several limitations still exist, and there is scope for further advancements. Several adverse effects are associated with modern chemotherapy that hinder cancer treatment and lead to other critical disorders. Since ancient times, plant-based medicines have been employed in clinical practice and have yielded good results with few side effects. The modern research system and advanced screening techniques for plants’ bioactive constituents have enabled phytochemical discovery for the prevention and treatment of challenging diseases such as cancer. Phytochemicals such as vincristine, vinblastine, paclitaxel, curcumin, colchicine, and lycopene have shown promising anticancer effects. Discovery of more plant-derived bioactive compounds should be encouraged via the exploitation of advanced and innovative research techniques, to prevent and treat advanced-stage cancers without causing significant adverse effects. This review highlights numerous plant-derived bioactive molecules that have shown potential as anticancer agents and their probable mechanisms of action and provides an overview of in vitro, in vivo and clinical trial studies on anticancer phytochemicals.

Peroxisome Proliferator Activated Receptor Gamma Coactivator-1 Alpha: A Double-Edged Sword in Prostate Cancer

Peroxisome proliferator activated receptor gamma coactivator-1 alpha (PGC-1α/PPARGC1A) is a pivotal transcriptional coactivator involved in the regulation of mitochondrial metabolism, including biogenesis and oxidative metabolism. PGC-1α is finely regulated by AMP-activated protein kinases (AMPKs), the role of which in tumors remains controversial to date. In recent years, a growing amount of research on PGC-1α and tumor metabolism has emphasized its importance in a variety of tumors, including prostate cancer (PCA). Compelling evidence has shown that PGC-1α may play dual roles in promoting and inhibiting tumor development under certain conditions. Therefore, a better understanding of the critical role of PGC-1α in PCA pathogenesis will provide new insights into targeting PGC-1α for the treatment of this disease. In this review, we highlight the procancer and anticancer effects of PGC-1α in PCA and aim to provide a theoretical basis for targeting AMPK/PGC-1α to inhibit the development of PCA. In addition, our recent findings provide a candidate drug target and theoretical basis for targeting PGC-1α to regulate lipid metabolism in PCA.

Metformin and Cancer Hallmarks: Molecular Mechanisms in Thyroid, Prostate and Head and Neck Cancer Models

Metformin is the most used drug for type 2 diabetes (T2DM). Its antitumor activity has been described by clinical studies showing reduced risk of cancer development in T2DM patients, as well as management of T2DM compared with those receiving other glucose-lowering drugs. Metformin has a plethora of molecular actions in cancer cells. This review focused on in vitro data on the action mechanisms of metformin on thyroid, prostate and head and neck cancer. AMPK activation regulating specific downstream targets is a constant antineoplastic activity in different types of cancer; however, AMPK-independent mechanisms are also relevant. In vitro evidence makes it clear that depending on the type of tumor, metformin has different actions; its effects may be modulated by different cell conditions (for instance, presence of HPV infection), or it may regulate tissue-specific factors, such as the Na⁺/I⁻ symporter (NIS) and androgen receptors. The hallmarks of cancer are a set of functional features acquired by the cell during malignant development. In vitro studies show that metformin regulates almost all the hallmarks of cancer. Interestingly, metformin is one of these therapeutic agents with the potential to synergize with other chemotherapeutic agents, with low cost, low side effects and high positive consequences. Some questions are still challenging: Are metformin in vitro data able to translate from bench to bedside? Does metformin affect drug resistance? Can metformin be used as a generic anticancer drug for all types of tumors? Which are the specific actions of metformin on the peculiarities of each type of cancer? Several clinical trials are in progress or have been concluded for repurposing metformin as an anticancer drug. The continuous efforts in the field and future in vitro studies will be essential to corroborate clinical trials results and to elucidate the raised questions.

Solamargine inhibits the growth of hepatocellular carcinoma and enhances the anticancer effect of sorafenib by regulating HOTTIP-TUG1/miR-4726-5p/MUC1 pathway

Hepatocellular carcinoma (HCC) is one of the most common primary malignancies. Drug resistance has significantly prevented the clinical application of sorafenib (SF), a first‐line targeted medicine for the treatment of HCC. Solamargine (SM), a natural alkaloid, has shown potential antitumor activity, but studies about antitumor effect of SM are obviously insufficient in HCC. In the present study, we found that SM significantly inhibited the growth of HCC and enhanced the anticancer effect of SF. In brief, SM significantly inhibited the growth of HepG2 and Huh‐7 cells. The combination of SM and SF showed a synergistic antitumor effect. Mechanistically, SM downregulated the expression of long noncoding RNA HOTTIP and TUG1, followed by increasing the expression of miR‐4726‐5p. Moreover, miR‐4726‐5p directly bound to the 3′‐UTR region of MUC1 and decreased the expression of MUC1 protein. Overexpression of MUC1 partially reversed the inhibitory effect of SM on HepG2 and Huh‐7 cells viability, which suggested that MUC1 may be the key target in SM‐induced growth inhibition of HCC. More importantly, the combination of SM and SF synergistically restrained the expression of MUC1 protein. Taken together, our study revealed that SM inhibited the growth of HCC and enhanced the anticancer effect of SF through HOTTIP‐TUG1/miR‐4726‐5p/MUC1 signaling pathway. These findings will provide potential therapeutic targets and strategies for the treatment of HCC.

Cancer Antigen 15-3/Mucin 1 Levels in CCTG MA.32: A Breast Cancer Randomized Trial of Metformin vs Placebo

Background

Circulating levels of cancer antigen (CA) 15-3, a tumor marker and regulator of cellular metabolism, were reduced by metformin in a nonrandomized neoadjuvant study. We examined the effects of metformin (vs placebo) on CA 15-3 in participants of MA.32, a phase III randomized trial in early-stage breast cancer.

Methods

A total of 3649 patients with T1-3, N0-3, M0 breast cancer were randomly assigned; pretreatment and 6-month on-treatment fasting plasma were centrally assayed for CA 15-3. Genomic DNA was analyzed for the rs11212617 single nucleotide polymorphism. Absolute and relative change of CA 15-3 (metformin vs placebo) were compared using Wilcoxon rank and t tests. Regression models adjusted for baseline differences and assessed key interactions. All statistical tests were 2-sided.

Results

Mean (SD) age was 52.4 (10.0) years. The majority of patients had T2/3, node-positive, hormone receptor-positive, HER2-negative breast cancer treated with (neo)adjuvant chemotherapy and hormone therapy. Mean (SD) baseline CA 15-3 was 17.7 (7.6) and 18.0 (8.1 U/mL). At 6 months, CA 15-3 was statistically significantly reduced in metformin vs placebo arms (absolute geometric mean reduction in CA 15-3 = 7.7% vs 2.0%, P < .001; relative metformin: placebo level of CA 15-3 [adjusted for age, baseline body mass index, and baseline CA 15-3] = 0.94, 95% confidence interval = 0.92 to 0.96). This reduction was independent of tumor characteristics, perioperative systemic therapy, baseline body mass index, insulin, and the single nucleotide polymorphism status (all Ps > .11).

Conclusions

Our observation that metformin reduces CA 15-3 by approximately 6% was corroborated in a large placebo-controlled randomized trial. The clinical implications of this reduction in CA 15-3 will be explored in upcoming efficacy analyses of breast cancer outcomes in MA.32.

Anti-tumor effects of Solanum nigrum L. extraction on C6 high-grade glioma

ETHNOPHARMACOLOGICAL RELEVANCE

Solanum nigrum L. (SN) is a traditional Chinese medicine with anti-tumor effects, has been used in cancer for centuries, but the role on high-grade gliomas (HGG) is not clear.

AIM OF THE STUDY

This work was to investigate the anti-tumor effects of SN extract on rat C6 glioma in vitro and in vivo, providing a new medium for the treatment of HGG.

MATERIALS AND METHODS

After identification and quality inspection of SN medicinal materials by HPLC-MS/MS and HPLC, CCK8 and colony formation assay were conducted to study the effects of SN on vitality and proliferation of C6 cells. Cell morphology was evaluated by HE staining, and flow cytometry was used for apoptosis analysis. The effects on cell migration and invasion were determined by transwell and wound healing assay. Western blot was used to further investigate the influence of SN on migration, invasion and apoptosis of tumor cells. In addition, the rat intracranial transplanted tumor model was used to evaluate the effects of SN on growth and infiltration of tumor and proliferation of transplanted tumor cells.

RESULTS

SN extract suppressed the viability of C6 cells in a dose-dependent manner. The extract attenuated cell cloning, migration and invasion, and induced cell Annexin V+ PI+ late-stage apoptosis. Besides, SN induced the expression of apoptotic proteins including Bax and Cleaved Caspase-3, downregulated anti-apoptotic protein Bcl-2, and decreased the level of migratory proteins MMP-2 and MMP-9. Moreover, SN reduced the growth and infiltration of C6 glioma tissue and suppressed the proliferation of tumor cells in rat brain.

CONCLUSIONS

SN extract has significant inhibitory activity on the growth and invasion of C6 HGG in vivo and in vitro.

Identification of the constituents and the cancer-related targets of the fruit of Solanum nigrum based on molecular docking and network pharmacology

The fruit of Solanum nigrum (FSN) exhibited a variety of biological activities. However, the chemical composition of the fruit, as well as the steroidal alkaloids responsible for the bioactivity and the mechanism of action need to be further studied. The ultrahigh performance liquid chromatography coupled with hybrid quadrupole-orbitrap mass spectrometry (UHPLC-Q Orbitrap HRMS) and nuclear magnetic resonance (NMR) were applied to investigate the chemical composition of FSN, which led to the identification of 170 compounds, including 12 amino acids, 4 caffeoylquinic acids, 2 flavonols, 114 steroid alkaloids, 5 steroid saponins and 33 other structure compounds. The network pharmacology showed that the anticancer effect of 14 steroid alkaloids was probably acting through 99 biological targets. Among them, 11 alkaloids and 11 targets probably played the important role based on the results of molecular docking. This study enriched our knowledge about the chemical composition of FSN, as well as the anticancer mechanism of steroidal alkaloids in FSN.

The Effect of Metformin on Male Reproductive Function and Prostate: An Updated Review

Metformin is the first-line oral antidiabetic drug that shows multiple pleiotropic effects of anti-inflamation, anti-cancer, anti-aging, anti-microbia, anti-atherosclerosis, and immune modulation. Metformin's effects on men's related health are reviewed here, focusing on reproductive health under subtitles of erectile dysfunction (ED), steroidogenesis and spermatogenesis; and on prostate-related health under subtitles of prostate specific antigen (PSA), prostatitis, benign prostate hyperplasia (BPH), and prostate cancer (PCa). Updated literature suggests a potential role of metformin on arteriogenic ED but controversial and contradictory effects (either protective or harmful) on testicular functions of testosterone synthesis and spermatogenesis. With regards to prostate-related health, metformin use may be associated with lower levels of PSA in humans, but its clinical implications require more research. Although there is a lack of research on metform's effect on prostatitis, it may have potential benefits through its anti-microbial and anti-inflammatory properties. Metformin may reduce the risk of BPH by inhibiting the insulin-like growth factor 1 pathway and some but not all studies suggest a protective role of metformin on the risk of PCa. Many clinical trials are being conducted to investigate the use of metformin as an adjuvant therapy for PCa but results currently available are not conclusive. While some trials suggest a benefit in reducing the metastasis and recurrence of PCa, others do not show any benefit. More research works are warranted to illuminate the potential usefulness of metformin in the promotion of men's health.

Probing the Antitumor Mechanism of Solanum nigrum L. Aqueous Extract against Human Breast Cancer MCF7 Cells

Solanum nigrum L. is one of the major medicinal plants used to treat cancer. However, the functional mechanism of S. nigrum L. extract is still unknown in spite of numerous studies on its active components. In this study, we probed the potential anticancer mechanism of the aqueous extract of S. nigrum L. (AESN) towards human breast cancer cell line MCF7. At a concentration of 10 g/L, AESN caused 43% cytotoxicity, inhibited the migration, and suppressed the activities of hexokinase and pyruvate kinase by about 30% and 40%, respectively, towards the MCF7 cells. RT²-PCR analysis of a panel of 89 caner-related genes identified 13 upregulated and eight downregulated genes (>2-folds) in MCF7 cells upon AESN treatment. Gene ontology (GO) and functional disease ontology (FunDO) analyses show that the antitumor function of S. nigrum L. involves multiple genes and these genes are shared across other diseases or disorders.

Novel reciprocal interaction of lncRNA HOTAIR and miR-214-3p contribute to the solamargine-inhibited PDPK1 gene expression in human lung cancer

Solamargine (SM) has been shown to have anti‐cancer properties. However, the underlying mechanism involved remains undetermined. We showed that SM inhibited the growth of non‐small cell lung cancer (NSCLC) cells, which was enhanced in cells with silencing of long non‐coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR), while it overcame by overexpression of HOTAIR. In addition, SM increased the expression of miR‐214‐3p and inhibited 3‐phosphoinositide‐dependent protein kinase‐1 (PDPK1) gene expression, which was strengthened by miR‐214‐3p mimics. Intriguingly, HOTAIR could directly bind to miR‐214‐3p and sequestered miR‐214‐3p from the target gene PDPK1. Intriguingly, overexpression of PDPK1 overcame the effects of SM on miR‐214‐3p expressions and neutralized the SM‐inhibited cell growth. Similar results were observed in vivo. In summary, our results showed that SM‐inhibited NSCLC cell growth through the reciprocal interaction between HOTAIR and miR‐214‐3p, which ultimately suppressed PDPK1 gene expression. HOTAIR effectively acted as a competing endogenous RNA (ceRNA) to stimulate the expression of target gene PDPK1. These complex interactions and feedback mechanisms contribute to the overall effect of SM. This unveils a novel molecular mechanism underlying the anti‐cancer effect of SM in human lung cancer.

Poly(I:C)-Mediated Death of Human Prostate Cancer Cell Lines Is Induced by Interleukin-27 Treatment

Interleukin (IL)-27 is a promising anti-cancer cytokine with therapeutic potential. Exhibiting overlapping properties with type I and II interferons (IFNs), IL-27 impacts cancer cell viability and immune cell activity. Known to modulate toll-like receptor (TLR) expression, we investigated whether IL-27 affected TLR-mediated death in cancer cells. Using DU145 and PC3 cell lines as models of prostate cancer, we investigated whether IL-27 and IFN-γ affect TLR3-mediated cell death. Our results demonstrate that when IL-27 or IFN-γ is added with polyinosinic-polycytidylic acid [poly(I:C)], type I IFN (IFN-I) expression increases concurrently with cell death. IL-27 and IFN-γ enhanced TLR3 expression, suggesting a mechanism for sensitization to cell death. Further, PC3 cells were more sensitive to IL-27/poly(I:C)-induced cell death compared with DU145 cells. This correlated with higher production of IFN-β and inducible protein-10 versus IL-6 in response to treatment of PC3 cells compared with DU145. Taken together, this study demonstrates a potential role for IL-27 in the treatment of prostate cancer.

Solamargine inhibits gastric cancer progression by regulating the expression of lncNEAT1_2 via the MAPK signaling pathway

Solamargine, a derivative from the steroidal solasodine in Solanum species, has exhibited anticancer activities in numerous types of cancer; however, its role in gastric cancer (GC) remains unknown. In the present study, it was demonstrated that Solamargine suppressed the viability of five gastric cancer cell lines in a dose‑dependent manner and induced notable alterations in morphology. Treatment with Solamargine promoted cell apoptosis (P<0.01). Solamargine increased the expression of long noncoding RNA (lnc) p53 induced transcript and lnc nuclear paraspeckle assembly transcript 1 (NEAT1)_2 (P<0.01) in GC by reducing the phosphorylation of extracellular signal‑regulated kinase (Erk)1/2 mitogen‑activated protein kinase (MAPK). To gain insight into the potential mechanism, an Erk1/2 inhibitor (U0126) was applied. The results revealed that lncNEAT1_2 expression levels increased, which was consistent with the effects of Solamargine. Downregulation of lncNEAT1_2 in GC cells revealed no effect on the expression levels of total Erk1/2 and, and counteracted the effect of Solamargine. Solamargine was observed to increase the expression of lncNEAT1_2 via the Erk1/2 MAPK signaling pathway. Of note, the knockdown of lncNEAT1_2 reduced the inhibitory effect of Solamargine (P<0.05). Additionally, experiments in vivo and in primary GC cells from patients demonstrated that Solamargine significantly suppressed tumor growth (P<0.05). In vivo analysis of a xenograft mouse model further supported that Solamargine could induce the apoptosis of cancer cells in tumor tissue as observed by a terminal deoxynucleotidyl transferase‑mediated dUTP‑biotin nick end labeling and H&E staining (P<0.05). Experiments in primary GC cells from patients verified the anti‑tumor effect of Solamargine. In summary, the findings of the present study indicated that Solamargine inhibited the progression of GC by regulating lncNeat1_2 via the MAPK pathway.

Metformin: A Bridge between Diabetes and Prostate Cancer

Prostate cancer (PCa) has become the most frequent type of cancer in men. Recent data suggest that diabetic patients taking metformin have a lower incidence of certain cancer, including PCa. Metformin is the most common drug used in type II diabetes mellitus; its use has been shown to lower the incidence of several cancers, although there are ambiguous data about the anticancer activity of metformin. A large number of studies examined the potential antineoplastic mechanism of metformin although it is not still completely understood. This review summarizes the literature concerning the effects of metformin on PCa cells, highlighting its numerous mechanisms of action through which it can act. We analyze the possible causes of the discordances regarding the impact of metformin on risk of PCa; we discuss the latest findings in this field, suggesting that metformin may have a future role in the management of PCa both as monotherapy and in combination with other drugs.