Metformin Potentiates the Anticancer Effect of Everolimus on Cervical Cancer In Vitro and In Vivo

Identification of a disulfidptosis-related genes signature for diagnostic and immune infiltration characteristics in cervical cancer

BACKGROUND

Cervical cancer (CC) ranks as the fourth most common malignancy affecting women globally, with research highlighting a rising incidence among younger age groups. Disulfidptosis, a newly identified form of regulated cell death, has been implicated in the pathogenesis of numerous diseases. This study employs bioinformatics analyses to explore the expression profiles and functional roles of disulfidptosis-related genes (DRGs) in the context of cervical cancer.

METHODS

Differential analysis of the gene expression matrix in CC was performed to identify differentially expressed genes. The overlap between these genes and disulfidptosis-related genes was then determined. Key hub genes were identified using multiple machine learning approaches, including LASSO regression, support vector machines (SVM), and random forest (RF). These hub genes were subsequently used to construct a predictive model, which was validated using external datasets to ensure robustness and reliability.

RESULTS

In this study, 11 overlapping genes were identified, among which four hub genes-BRK1, NDUFA11, RAC1, and NDUFS1-were extracted using machine learning techniques. The diagnostic performance of these hub genes was validated with external datasets, and a predictive model was constructed based on their expression. The model demonstrated an exceptionally high area under the curve (AUC) of 0.997. Moreover, AUC values exceeding 0.85 for two independent validation datasets further confirmed the model's accuracy and stability. Notably, NDUFA11 and BRK1 showed significant associations with patient survival, highlighting their prognostic importance in cervical squamous cell carcinoma. Using CMAP and DGIdb databases, Metformin and Coenzyme-I were identified as potential targeted therapies for NDUFS1 and NDUFA11, respectively, offering new therapeutic avenues for patients.

CONCLUSION

This study uncovered a strong association between disulfidptosis and CC and developed a predictive model to assess the risk in CC patients. These findings offer novel insights into identifying biomarkers and potential therapeutic targets for CC, paving the way for improved diagnostic and treatment strategies.

Metformin upregulates circadian gene PER2 to inhibit growth and enhance the sensitivity of glioblastoma cell lines to radiotherapy via SIRT2/G6PD pathway

Introduction

Glioblastoma multiform (GBM) is considered the deadliest brain cancer. Standard therapies are followed by poor patient's survival outcomes, so novel and more efficacious therapeutic strategies are imperative to tackle this scourge. Metformin has been reported to have anti-cancer effects. However, the precise mechanism underlying these effects remains elusive. A better understanding of its underlying mechanism will inform future experimental designs exploring metformin as a potential adjuvant therapy for GBM. This research aimed to elucidate the potential molecular mechanism of metformin in GBM by integrating proteomics and transcriptomics.

Methods

The study examined the effects of metformin on GBM cell lines using various methods. The U87, U251 and HA1800 were cultured and modified through PER2 knockdown and overexpression. Cell viability was assessed using the CCK8 assay, and G6PDH activity and intracellular NADPH+ levels were measured with specific kits. ROS levels, mitochondrial membrane potential, cell cycle distribution and apoptosis were analyzed by flow cytometry. RNA was extracted for transcriptomic analysis through RNA sequencing, while proteomic analysis was performed on total protein from treated cells. WB detected specific proteins, and RT-qPCR quantified gene expression. In vivo experiments, GBM xenograft on nude mice treated with metformin combining radiotherapy was evaluated and received IHC and TUNEL staining for protein expression and apoptosis assessment. Statistical analyses were conducted using Prism software to identify significant group differences.

Results

We found that differential expressional genes and proteins relating to circadian rhythm were enriched in proteomic or transcriptomic. The expression of PER2, the key circadian gene, was up-regulated in GBM cell lines when treated with metformin. Furthermore, the expression of silent information regulator 2(SIRT2) was down-regulated, while the expression of the G6PD protein just slightly increased in GBM cell lines. Meanwhile, NADPH+ production and G6PDH enzyme activity significantly decreased. Further study validated that metformin inhibited the cell growth of GBM cell lines through up-regulating PER2 and inhibited SIRT2/G6PD signaling pathway, enhancing radiotherapy(RT) sensitivity. We also found that the inhibition of SIRT2 caused by metformin is mediated by PER2.

Discussion

We found the pivotal role of metformin as an effective circadian rhythm regulator. Targeting circadian clock gene to modify and rescue the dysfunctional circadian clock of GBM cells at molecular level might be an innovative way to administer cancer chronotherapy and maintain metabolic homeostasis in real world practice.

Proteomics-based network pharmacology and molecular docking reveal the potential mechanisms of 5,6,7,4'-tetramethoxyflavone against HeLa cancer cells

Recent research has highlighted the therapeutic potential of citrus-derived dietary 5,6,7,4'-tetramethoxyflavone (TMF) against HeLa cancer. Our study aims to elucidate its mechanisms of action through proteomics analysis, network pharmacology, and molecular docking. The results suggested that TMF demonstrated efficacy by upregulating CD40, CD40L, Fas, Fas-L, HSP27, HSP60, IGFBP-1, IGFBP-2, IGF-1sR, Livin, p21, p27, sTNFR2, TRAILR2, TRAILAR3, TRAILR4, XIAP, p-Sre, p-Stat1, p-Stat2 p-c-Fos, p-SMAD1, p-SMAD2, p-SMAD4, p-SMAD5, p-IκBα, p-MSK1, p-NFκB, p-TAK1, p-TBK1, p-ZAP70, and p-MSK2, while downregulating p-EGFR, p-ATF2, p-cJUN, p-HSP27, p-JNK, and p-GSK3A. These targets are primarily involved in MAPK, apoptosis, and TNF signaling pathways. Notably, p21, p27, EGFR, SMAD4, JNK, ATF2, and c-JUN merged as pivotal targets contributing to TMF's anti-cancer efficacy against HeLa cells. This study is first to delineate the potential signaling pathways and core targets of TMF in treating of HeLa cancer, paving the way for further exploration of TMF's medical potential.

Metformin in the treatment of colorectal cancer and neuroendocrine tumours

Colorectal cancer is being detected in increasingly younger age groups, and its incidence has been on the rise in recent years. Neuroendocrine tumors have also shown an increase in occurrence despite their rarity. Neuroendocrine tumors most commonly occur in the gastrointestinal tract and lungs. Therefore, new, better, and more effective treatment methods are being sought. Metformin, a drug commonly used in the treatment of type 2 diabetes, has demonstrated its ability to reduce the incidence and increase the efficacy of chemotherapy in colorectal cancer and neuroendocrine tumors. The biguanide works by inhibiting the mammalian target of rapamycin pathway, activating 5'AMP activated protein kinase, and reducing insulin-like growth factor 1. In studies conducted on human cells and xenografts, the drug has shown its positive effects in combating these tumors by reducing proliferation, slowing the growth of cancer cells, and inhibiting metastasis. The main goal of this review is to comprehensively summarize the current state of knowledge regarding metformin in the treatment of colorectal cancer and neuroendocrine tumors.

Changes in the Sensitivity of MCF-7 and MCF-7/DX Breast Cancer Cells to Cytostatic in the Presence of Metformin

Multidrug resistance is a serious problem in modern medicine and the reason for the failure of various therapies. A particularly important problem is the occurrence of multidrug resistance in cancer therapies which affects many cancer patients. Observations on the effect of metformin-a well-known hypoglycemic drug used in the treatment of type 2 diabetes-on cancer cells indicate the possibility of an interaction of this substance with drugs already used and, as a result, an increase in the sensitivity of cancer cells to cytostatics. The aim of this study was to evaluate the effect of metformin on the occurrence of multidrug resistance of breast cancer cells. The MCF-7-sensitive cell line and the MCF-7/DX cytostatic-resistant cell line were used for this study. WST-1 and LDH assays were used to evaluate the effects of metformin and doxorubicin on cell proliferation and viability. The effect of metformin on increasing the sensitivity of MCF-7 and MCF-7/DX cells to doxorubicin was evaluated in an MDR test. The participation of metformin in increasing the sensitivity of resistant cells to the effect of the cytostatic (doxorubicin) has been demonstrated.

Molecular Mechanisms Underlying the Anticancer Properties of Pitavastatin against Cervical Cancer Cells

Cervical cancer ranks as the fourth most prevalent form of cancer and is a significant contributor to female mortality on a global scale. Pitavastatin is an anti-hyperlipidemic medication and has been demonstrated to exert anticancer and anti-inflammatory effects. Thus, the purpose of this study was to evaluate the anticancer effect of pitavastatin on cervical cancer and the underlying molecular mechanisms involved. The results showed that pitavastatin significantly inhibited cell viability by targeting cell-cycle arrest and apoptosis in Ca Ski, HeLa and C-33 A cells. Pitavastatin caused sub-G1- and G0/G1-phase arrest in Ca Ski and HeLa cells and sub-G1- and G2/M-phase arrest in C-33 A cells. Moreover, pitavastatin induced apoptosis via the activation of poly-ADP-ribose polymerase (PARP), Bax and cleaved caspase 3; inactivated the expression of Bcl-2; and increased mitochondrial membrane depolarization. Furthermore, pitavastatin induced apoptosis and slowed the migration of all three cervical cell lines, mediated by the PI3K/AKT and MAPK (JNK, p38 and ERK1/2) pathways. Pitavastatin markedly inhibited tumor growth in vivo in a cancer cell-originated xenograft mouse model. Overall, our results identified pitavastatin as an anticancer agent for cervical cancer, which might be expanded to clinical use in the future.

Activation of AMPK inhibits cervical cancer growth by hyperacetylation of H3K9 through PCAF

BACKGROUND

Dysregulation in histone acetylation, a significant epigenetic alteration closely associated with major pathologies including cancer, promotes tumorigenesis, inactivating tumor-suppressor genes and activating oncogenic pathways. AMP-activated protein kinase (AMPK) is a cellular energy sensor that regulates a multitude of biological processes. Although a number of studies have identified the mechanisms by which AMPK regulates cancer growth, the underlying epigenetic mechanisms remain unknown.

METHODS

The impact of metformin, an AMPK activator, on cervical cancer was evaluated through assessments of cell viability, tumor xenograft model, pan-acetylation analysis, and the role of the AMPK-PCAF-H3K9ac signaling pathway. Using label-free quantitative acetylproteomics and chromatin immunoprecipitation-sequencing (ChIP) technology, the activation of AMPK-induced H3K9 acetylation was further investigated.

RESULTS

In this study, we found that metformin, acting as an AMPK agonist, activates AMPK, thereby inhibiting the proliferation of cervical cancer both in vitro and in vivo. Mechanistically, AMPK activation induces H3K9 acetylation at epigenetic level, leading to chromatin remodeling in cervical cancer. This also enhances the binding of H3K9ac to the promoter regions of multiple tumor suppressor genes, thereby promoting their transcriptional activation. Furthermore, the absence of PCAF renders AMPK activation incapable of inducing H3K9 acetylation.

CONCLUSIONS

In conclusion, our findings demonstrate that AMPK mediates the inhibition of cervical cancer growth through PCAF-dependent H3K9 acetylation. This discovery not only facilitates the clinical application of metformin but also underscores the essential role of PCAF in AMPK activation-induced H3K9 hyperacetylation.

Comprehensive review of the repositioning of non-oncologic drugs for cancer immunotherapy

Drug repositioning or repurposing has gained worldwide attention as a plausible way to search for novel molecules for the treatment of particular diseases or disorders. Drug repurposing essentially refers to uncovering approved or failed compounds for use in various diseases. Cancer is a deadly disease and leading cause of mortality. The search for approved non-oncologic drugs for cancer treatment involved in silico modeling, databases, and literature searches. In this review, we provide a concise account of the existing non-oncologic drug molecules and their therapeutic potential in chemotherapy. The mechanisms and modes of action of the repurposed drugs using computational techniques are also highlighted. Furthermore, we discuss potential targets, critical pathways, and highlight in detail the different challenges pertaining to drug repositioning for cancer immunotherapy.

The function, mechanisms, and clinical applications of metformin: potential drug, unlimited potentials

Metformin has been used clinically for more than 60 years. As time goes by, more and more miraculous effects of metformin beyond the clinic have been discovered and discussed. In addition to the clinically approved hypoglycemic effect, it also has a positive metabolic regulation effect on the human body that cannot be ignored. Such as anti-cancer, anti-aging, brain repair, cardiovascular protection, gastrointestinal regulation, hair growth and inhibition of thyroid nodules, and other nonclinical effects. Metformin affects almost the entire body in the situation taking it over a long period, and the preventive effects of metformin in addition to treating diabetes are also beginning to be recommended in some guidelines. This review is mainly composed of four parts: the development history of metformin, the progress of clinical efficacy, the nonclinical efficacy of metformin, and the consideration and prospect of its application.

The Potential Therapeutic Impact of Metformin in Glioblastoma Multiforme

In terms of frequency and aggressiveness, glioblastoma multiforme (GBM) is undoubtedly the most frequent and fatal primary brain tumor. Despite advances in clinical management, the response to current treatments is dismal, with a 2-year survival rate varying between 6 and 12 percent. Metformin, a derivative of biguanide widely used in treating type 2 diabetes, has been shown to extend the lifespan of patients with various malignancies. There is limited evidence available on the long-term survival of GBM patients who have taken metformin. This research examined the literature to assess the connection between metformin's anticancer properties and GBM development. Clinical findings, together with the preclinical data from animal models and cell lines, are included in the present review. This comprehensive review covers not only the association of hyperactivation of the AMPK pathway with the anticancer activity of metformin but also other mechanisms underpinning its role in apoptosis, cell proliferation, metastasis, as well as its chemo-radio-sensitizing behavior against GBM. Current challenges and future directions for developments and applications of metformin-based therapeutics are also discussed.

Metformin suppresses foam cell formation, inflammation and ferroptosis via the AMPK/ERK signaling pathway in ox‑LDL‑induced THP‑1 monocytes

Numerous studies have shown that the formation of foam cells is of vital importance in the process of atherosclerosis. The aim of the present study was to assess the effects of metformin on foam cell formation in oxidized low-density lipoprotein (ox-LDL)-treated THP-1 cells and explore its associated mechanism of action. Human monocytic THP-1 cells were pretreated with metformin for 2 h and subsequently treated with ox-LDL for 24 h. The data indicated that metformin significantly inhibited lipid accumulation in ox-LDL-treated THP-1 cells by decreasing the expression of scavenger receptor A, cluster of differentiation 36 and adipocyte enhancer-binding protein 1. In addition, metformin increased the expression levels of scavenger receptor B1 and ATP binding cassette transporter G1 and suppresses the esterification of free cholesterol. Furthermore, it markedly inhibited ferroptosis (reflected by the upregulation of glutathione peroxidase glutathione peroxidase 4 and the downregulation of Heme oxygenase-1). In addition, it caused a marked suppression in the expression levels of cysteinyl aspartate specific proteinase-1, IL-1β, NOD-like receptor protein 3, IL-18 secretion and in the levels of oxidative stress. Metformin attenuated the activation of ERK and facilitated the phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK). Treatment of THP-1 cells with an ERK inhibitor reversed these effects, while inhibition of AMPK activity exacerbated the effects noted in ox-LDL-treated THP-1 cells. In conclusion, the present study suggested that metformin suppressed foam cell formation, inflammatory responses and inhibited ferroptosis in ox-LDL-treated macrophages via the AMPK/ERK signaling pathway.

Metformin Enhancement of Therapeutic Effects of 5-Fluorouracil and Oxaliplatin in Colon Cancer Cells and Nude Mice

Studies have demonstrated that metformin has antitumor effects in addition to therapeutic effects on hyperglycemia; however, few studies have explored the effects of metformin in chemotherapy. Therefore, we hypothesized that the administration of metformin would enhance the therapeutic effects of 5-fluorouracil and oxaliplatin (FuOx) to inhibit the growth of colorectal cancer (CRC) cells in vitro and in vivo. The results of our in vitro experiments demonstrated that metformin significantly increased the effects of FuOx with respect to cell proliferation (p < 0.05), colony formation (p < 0.05), and migration (p < 0.01) and induced cell cycle arrest in the G0/G1 phase in HT29 cells and the S phase in SW480 and SW620 cells (p < 0.05). Flow cytometry analysis revealed that metformin combined with FuOx induced late apoptosis (p < 0.05) by mediating mitochondria-related Mcl-1 and Bim protein expression. Furthermore, in vivo, metformin combined with FuOx more notably reduced tumor volume than FuOx or metformin alone did in BALB/c mice (p < 0.05). These findings demonstrate that metformin may act as an adjunctive agent to enhance the chemosensitivity of CRC cells to FuOx. However, further clinical trials are warranted to validate the clinical implications of the findings.