STAT3 and p53: Dual Target for Cancer Therapy

It's all downstream from here: RTK/Raf/MEK/ERK pathway resistance mechanisms in glioblastoma

BACKGROUND

The receptor tyrosine kinase (RTK)/Ras/Raf/MEK/ERK signaling pathway is one of the most tumorigenic pathways in cancer, with its hyperactivation strongly linked to the aggressive nature of glioblastoma (GBM). Although extensive research has focused on developing therapeutics targeting this pathway, clinical success remains elusive due to the emergence of resistance mechanisms.

OBJECTIVE

This review investigates how inhibition of the RTK/Ras/Raf/MEK/ERK pathway alters transcription factors, contributing to acquired resistance mechanisms in GBM. It also highlights the critical role of transcription factor dysregulation in therapeutic resistance.

METHODS & RESULTS

Findings from key studies on the RTK/Ras/Raf/MEK/ERK pathway in GBM were synthesized to explore the role of transcription factor dysregulation in resistance to targeted therapies, radiation, and chemotherapy. The review highlights that transcription factors undergo significant dysregulation following RTK/Ras/Raf/MEK/ERK pathway inhibition, contributing to therapeutic resistance.

CONCLUSION

Transcription factors are promising targets for overcoming treatment resistance in GBM, with cotreatment strategies combining RTK/Ras/Raf/MEK/ERK pathway inhibitors and transcription factor-targeted therapies presenting a novel approach. Despite the challenges of targeting complex structures and interactions, advancements in drug development and precision technologies hold great potential. Continued research is essential to refine these strategies and improve outcomes for GBM and other aggressive cancers.

Chemical Information Network and Molecular Docking Inspire the Novel Indole Discovery Against Glioma from Tabernaemontana corymbosa

The alkaloid ingredients were considered to be responsible for the diverse pharmacological activities of the medicinal plant Tabernaemontana corymbosa (Roxb. ex Wall.). In the current finding, the systematic phytochemical investigation on T. corymbosa have been achieved. One new indole alkaloid tabercorympyline A (1) along with seven known indoles (2-8) were isolated from T. corymobsa. Their structures were elucidated by means of spectroscopic techniques and quantum chemical calculations. Tabercorympyline A (1) possessed the indole skeleton with rare N-containing nine membered ring. Chemical information network was used to comprehensively discover the clues for the glioma therapeutic leads from T. corymbosa alkaloids (TA). Inspired by chemical information network analysis, all the isolated compounds have been further validated their anti glioma activities in glioma cell line U251. Interestingly, the compounds 2, 3, 5, and 6 exhibited significant inhibitory effects on glioma cells in vitro. Molecular docking was ultimately used to indicate possible binding performance and mechanism between active compounds (2-3) and the core targets. This study sequentially assembled chemical information and network analysis, phytochemistry, molecular docking, and in vitro activity validation to comprehensively explore the effective compounds, related targets, and potential mechanisms of TA therapy for glioma.

Probiotic Mixture Attenuates Colorectal Tumorigenesis in Murine AOM/DSS Model by Suppressing STAT3, Inducing Apoptotic p53 and Modulating Gut Microbiota

Colorectal cancer (CRC) is one of the most common cancers worldwide. The standard CRC chemo drug, 5-Fluorouracil (5-FU), has a poor response rate and chemoresistance, prompting the need for a more effective and affordable treatment. In this study, we aimed to evaluate whether Prohep, a novel probiotic mixture, would alleviate azoxymethane/dextran sodium sulfate (AOM/DSS)-induced colorectal tumorigenesis and enhance 5-FU efficacy and its mechanism. Our results suggested that Prohep showed stronger anti-tumorigenesis effects than 5-FU alone or when combined in the AOM/DSS model. Prohep significantly reduced the total tumor count, total tumor size, caecum weight, colonic crypt depth, colonic inflammation, and collagen fibrosis. Prohep downregulated pro-inflammatory TNF-α and proliferative p-STAT3 and upregulated apoptotic p53. Metagenomics analysis indicated that Prohep-enriched Helicobacter ganmani, Desulfovibrio porci, Helicobacter hepaticus, and Candidatus Borkfalkia ceftriaxoniphila were inversely correlated to the total tumor count. In addition, Prohep-enriched Prevotella sp. PTAC and Desulfovibrio porci were negatively correlated to AOM/DSS enriched bacteria, while forming a co-existing community with other beneficial bacteria. From KEGG analysis, Prohep downregulated CRC-related pathways and enhanced pathways related to metabolites suppressing CRC like menaquinone, tetrapyrrole, aminolevulinic acid, and tetrahydrofolate. From Metacyc analysis, Prohep downregulated CRC-related peptidoglycan, LPS, and uric acid biosynthesis, and conversion. Prohep elevated the biosynthesis of the beneficial L-lysine, lipoic acid, pyrimidine, and palmitate. Prohep also elevated metabolic pathways related to energy utilization of lactic acid-producing bacteria (LAB) and acetate producers. Similarly, fecal acetate concentration was upregulated by Prohep. To sum up, Prohep demonstrated exceptional anti-tumorigenesis effects in the AOM/DSS model, which revealed its potential to develop into a novel CRC therapeutic in the future.

Clinical Applications of Antisense Oligonucleotides in Cancer: A Focus on Glioblastoma

Antisense oligonucleotides (ASOs) are promising drugs capable of modulating the protein expression of virtually any target with high specificity and high affinity through complementary base pairing. However, this requires a deep understanding of the target sequence and significant effort in designing the correct complementary drug. In addition, ASOs have been demonstrated to be well tolerated during their clinical use. Indeed, they are already used in many diseases due to pathogenic RNAs of known sequences and in several neurodegenerative diseases and metabolic diseases, for which they were given marketing authorizations (MAs) in Europe and the United States. Their use in oncology is gaining momentum with several identified targets, promising preclinical and clinical results, and recent market authorizations in the US. However, many challenges remain for their clinical use in cancer. It seems necessary to take a step back and review our knowledge of ASOs and their therapeutic uses in oncology. The objectives of this review are (i) to summarize the current state of the art of ASOs; (ii) to discuss the therapeutic use of ASOs in cancer; and (iii) to focus on ASO usage in glioblastoma, the challenges, and the perspective ahead.

GOLPH3 promotes tumor malignancy via inhibition of ferroptosis by upregulating SLC7A11 in cholangiocarcinoma

Golgi phosphoprotein 3 (GOLPH3) has been reported as an oncogene in various tumors; however, the role and function of GOLPH3 and its relevant molecular mechanism in cholangiocarcinoma (CCA) are unclear. Herein, GOLPH3 expression in CCA tissues was observed to be significantly higher than that in paired adjacent noncancerous tissues. Clinicopathological analysis showed that GOLPH3 expression correlated positively with the tumor-node-metastasis stage. In addition, GOLPH3 expression correlated inversely with the overall survival of patients with CCA. Multivariate analysis showed that GOLPH3 was an independent prognostic factor for patients with CCA. Transcriptome analysis (RNA sequencing) of GOLPH3 knockdown cells showed that the expression levels of nine ferroptosis-related genes were significantly changed, indicating the important biological function of GOLPH3 in ferroptosis in CCA cells. Furthermore, GOLPH3 knockdown could significantly promote Erastin-induced ferroptosis in vitro and suppress tumor growth in vivo. Overexpression of GOLPH3 had the opposite effect on this phenotype. Further studies revealed that GOLPH3 knockdown was significantly associated with a decrease in cysteine content, an accumulation of the lipid peroxidation product malondialdehyde, an increase in reactive oxygen species, and sensitized CCA cells to Erastin-induced ferroptosis. Moreover, changes in GOLPH3 expression were found to be consistent with the expression of light chain subunit solute carrier family 7 member 11 (SLC7A11). Thus, our study suggested that GOLPH3 functions as an oncoprotein in CCA and may suppress ferroptosis by facilitating SLC7A11 expression, suggesting that GOLPH3 could serve as a therapeutic target for CCA treatment.

Unfolded protein response suppression potentiates LPS-induced barrier dysfunction and inflammation in bovine pulmonary artery endothelial cells

The development of novel strategies to counteract diseases related to barrier dysfunction is a priority, since sepsis and acute respiratory distress syndrome are still associated with high mortality rates. In the present study, we focus on the effects of the unfolded protein response suppressor (UPR) 4-Phenylbutyrate (4-PBA) in Lipopolysaccharides (LPS)-induced endothelial injury, to investigate the effects of that compound in the corresponding damage. 4-PBA suppressed binding immunoglobulin protein (BiP) - a UPR activation marker - and potentiated LPS - induced signal transducer and activator of transcription 3 (STAT3) and extracellular signal‑regulated protein kinase (ERK) 1/2 activation. In addition to those effects, 4-PBA enhanced paracellular hyperpermeability in inflamed bovine pulmonary endothelial cells, and did not affect cell viability in moderate concentrations. Our observations suggest that UPR suppression due to 4-PBA augments LPS-induced endothelial injury, as well as the corresponding barrier disruption.

KIAA0040 enhances glioma growth by controlling the JAK2/STAT3 signalling pathway

The role of KIAA0040 role in glioma development is not yet understood despite its connection to nervous system diseases. In this study, KIAA0040 expression levels were evaluated using qRT-PCR, WB and IHC, and functional assays were conducted to assess its impact on glioma progression, along with animal experiments. Moreover, WB was used to examine the impact of KIAA0040 on the JAK2/STAT3 signalling pathway. Our study found that KIAA0040 was increased in glioma and linked to tumour grade and poor clinical outcomes, serving as an independent prognostic factor. Functional assays showed that KIAA0040 enhances glioma growth, migration and invasion by activating the JAK2/STAT3 pathway. Of course, KIAA0040 enhances glioma growth by preventing tumour cell death and promoting cell cycle advancement. Our findings suggest that targeting KIAA0040 could be an effective treatment for glioma due to its role in promoting aggressive tumour behaviour and poor prognosis.

Hepatocellular Carcinoma: Old and Emerging Therapeutic Targets

Liver cancer, predominantly hepatocellular carcinoma (HCC), globally ranks sixth in incidence and third in cancer-related deaths. HCC risk factors include non-viral hepatitis, alcohol abuse, environmental exposures, and genetic factors. No specific genetic alterations are unequivocally linked to HCC tumorigenesis. Current standard therapies include surgical options, systemic chemotherapy, and kinase inhibitors, like sorafenib and regorafenib. Immunotherapy, targeting immune checkpoints, represents a promising avenue. FDA-approved checkpoint inhibitors, such as atezolizumab and pembrolizumab, show efficacy, and combination therapies enhance clinical responses. Despite this, the treatment of hepatocellular carcinoma (HCC) remains a challenge, as the complex tumor ecosystem and the immunosuppressive microenvironment associated with it hamper the efficacy of the available therapeutic approaches. This review explores current and advanced approaches to treat HCC, considering both known and new potential targets, especially derived from proteomic analysis, which is today considered as the most promising approach. Exploring novel strategies, this review discusses antibody drug conjugates (ADCs), chimeric antigen receptor T-cell therapy (CAR-T), and engineered antibodies. It then reports a systematic analysis of the main ligand/receptor pairs and molecular pathways reported to be overexpressed in tumor cells, highlighting their potential and limitations. Finally, it discusses TGFβ, one of the most promising targets of the HCC microenvironment.

Natural bioactive compounds and STAT3 against hepatocellular carcinoma: An update

Hepatocellular carcinoma (HCC) is a challenging and very fatal liver cancer. The signal transducer and activator of transcription 3 (STAT3) pathway is a crucial regulator of tumor development and are ubiquitously active in HCC. Therefore, targeting STAT3 has emerged as a promising approach for preventing and treating HCC. Various natural bioactive compounds (NBCs) have been proven to target STAT3 and have the potential to prevent and treat HCC as STAT3 inhibitors. Numerous kinds of STAT3 inhibitors have been identified, including small molecule inhibitors, peptide inhibitors, and oligonucleotide inhibitors. Due to the undesirable side effects of the conventional therapeutic drugs against HCC, the focus is shifted to NBCs derived from plants and other natural sources. NBCs can be broadly classified into the categories of terpenes, alkaloids, carotenoids, and phenols. Most of the compounds belong to the family of terpenes, which prevent tumorigenesis by inhibiting STAT3 nuclear translocation. Further, through STAT3 inhibition, terpenes downregulate matrix metalloprotease 2 (MMP2), matrix metalloprotease 9 (MMP9) and vascular endothelial growth factor (VEGF), modulating metastasis. Terpenes also suppress the anti-apoptotic proteins and cell cycle markers. This review provides comprehensive information related to STAT3 abrogation by NBCs in HCC with in vitro and in vivo evidences.

Circ_0004676 exacerbates triple-negative breast cancer progression through regulation of the miR-377-3p/E2F6/PNO1 axis

BACKGROUND

The significant roles of circular RNAs (circRNAs) in different cancers and diseases have been reported. We now focused on the possible role of a newly recognized circRNA, circ_0004674 in triple-negative breast cancer (TNBC), and the related downstream mechanism.

METHODS

The expression of circ_0004674 in TNBC tissues and cells was determined followed by analysis of the correlation between circ_0004674 and TNBC patients' prognosis. The interaction between circ_0004674, miR-377-3p, E2F6, and PNO1 was then identified using bioinformatics analysis combined with FISH, RIP, RNA pull-down, RT-qPCR, and Western blot analysis. Using gain-of-function and loss-of-function methods, we analyzed the effect of circ_0004674, miR-377-3p, E2F6, and PNO1 on TNBC in vivo and in vitro.

RESULTS

Increased circ_0004674 and E2F6 but decreased miR-377-3p were observed in TNBC tissues and MDA-MB-231 TNBC cells, all of which findings were associated with poor prognosis in patients with TNBC. Silencing of circ_0004676 remarkably suppressed the proliferation, cell cycle progression, and migration of TNBC cells in vitro, as well as inhibiting tumorigenesis and metastasis in vivo. Additionally, circ_0004676 served as a sponge of miR-377-3p which bound to the transcription factor E2F6. In the presence of overexpression of circ_0004676, E2F6 expression and its target PNO1 expression were elevated, while miR-377-3p expression was decreased. Interestingly, overexpression of E2F6 could reverse the inhibitory effect on tumor growth caused by downregulation of circ_0004676.

CONCLUSION

Our study highlighted the carcinogenic effect of circ_0004676 on TNBC through regulation of the miR-377-3p/E2F6/PNO1 axis. 1. Circ_0004674 is highly expressed in TNBC tissues and cells. 2. Circ_0004674 upregulates the expression of E2F6 by sponging miR-377-3p. 3. E2F6 upregulates PNO1 by binding to the PNO1 promoter. 4. Circ_0004674 favors TNBC progression by regulating the miR-377-3p/E2F6/PNO1 axis. 5. This study provides a new target for the treatment of TNBC.

Pterostilbene induces apoptosis in hepatocellular carcinoma cells: Biochemical, pathological, and molecular markers

Worldwide, hepatocellular carcinoma (HCC) is considered the sixth most prevalent cancer and ranked third in causes leading to death. Pterostilbene (PTE), a dimethylated analog of resveratrol, is a phytochemical found in fruits such as blueberries and grapes, and is known for its anticancer effect. The current study intended to investigate the effect of PTE on HepG2 cells. Cell viability, colony-forming potential, lipid peroxidation, catalase enzyme (CAT), superoxide dismutase (SOD), and caspase 3 activities, histone release, and expression levels of mTOR, S6K1, p53, and STAT3 proteins were assessed in PTE-treated HepG2 cells. In addition, the cellular and ultrastructural alterations were evaluated by light and transmission electron microscopy. PTE induced a significant reduction in HepG2 viability in a dose-dependent manner (IC₅₀ of PTE = 74 ± 6 μM), accompanied by a decrease in colony formation potential. PTE-treated cancer cells exhibited a decrease in lipid peroxidation and CAT activity, and an increase in histone release, caspase-3, and SOD activities. Ultrastructurally, PTE-treated cells exhibited notable cell shrinkage, reduced number of filopodia, increased vacuolization, apoptotic bodies, accumulation of lipid droplets, enlarged mitochondria, dilated endoplasmic reticulum, pyknotic nuclei, and cellular fragmentation. mTOR, S6K1, and STAT3 levels were downregulated, however p53 level was modulated in PTE-treated cells. The anticancer potential of PTE might be related to its ability to alter the ultrastructure morphology, reduce mitotic activity, and modulate some key protein required for cell proliferation, suggesting its potential to trigger cancer cells towards apoptosis.

MAT2A inhibits the ferroptosis in osteosarcoma progression regulated by miR-26b-5p

Osteosarcoma (OS) is the most frequent primary malignant bone tumor. Ferroptosis, a form of regulated cell death, is a key tumor suppression mechanism. Although methionine adenosyltransferase II alpha (MAT2A) has been reported to inhibit several tumor cells, it is unclear whether inhibition of MAT2A in OS cells can reduce ferroptosis. CCK-8, flow cytometry, and Transwell assays were performed to evaluate cell viability, cell apoptosis/cycle, and cell migration, respectively. The levels of ferrous iron and glutathione (GSH) levels in cells were measured to evaluate the degree of cell ferroptosis. Western blot analysis was performed to detect protein levels of MAT2A, p-STAT3 (Ser727)/STAT3, and solute carrier family 7 member 11 (SLC7A11) in OS cells. MAT2A was significantly upregulated in OS specimens and high MAT2A expression was associated with a poorer prognosis in OS patients. shRNA targeting MAT2A significantly increased OS cell apoptosis, triggered cell cycle arrest in the G2 phase, and attenuated migration ability in vitro. MAT2A depletion dramatically inhibited tumor progression of OS in vivo. Overexpression of MAT2A rescued the tumor inhibition caused by miR-26b-5p. MAT2A knockdown promoted OS cell ferroptosis. miR-26b-5p/MAT2A regulates tumor malignant progression and OS cell ferroptosis by controlling p-STAT3 and SLC7A11 expressions. Taken together, our study displayed that miR-26b-5p/MAT2A triggers ferroptosis in OS cells by increasing intracellular ferrous iron levels and inhibiting the STAT3/SLC7A11 axis. Our results reveal a MAT2A-mediated ferroptosis defense mechanism used by OS cells and propose a potential ferroptosis-inducing strategy for the treatment of OS patients.

Optimal ranking and directional signature classification using the integral strategy of multi-objective optimization-based association rule mining of multi-omics data

Introduction: Association rule mining (ARM) is a powerful tool for exploring the informative relationships among multiple items (genes) in any dataset. The main problem of ARM is that it generates many rules containing different rule-informative values, which becomes a challenge for the user to choose the effective rules. In addition, few works have been performed on the integration of multiple biological datasets and variable cutoff values in ARM. Methods: To solve all these problems, in this article, we developed a novel framework MOOVARM (multi-objective optimized variable cutoff-based association rule mining) for multi-omics profiles. Results: In this regard, we identified the positive ideal solution (PIS), which maximized the profit and minimized the loss, and negative ideal solution (NIS), which minimized the profit and maximized the loss for all gene sets (item sets), belonging to each extracted rule. Thereafter, we computed the distance (d +) from PIS and distance (d -) from NIS for each gene set or product. These two distances played an important role in determining the optimized associations among various pairs of genes in the multi-omics dataset. We then globally estimated the relative closeness to PIS for ranking the gene sets. When the relative closeness score of the rule is greater than or equal to the pre-defined threshold value, the rule can be considered a final resultant rule. Moreover, MOOVARM evaluated the relative score of the rule based on the status of all genes instead of individual genes. Conclusions: MOOVARM produced the final rank of the extracted (multi-objective optimized) rules of correlated genes which had better disease classification than the state-of-the-art algorithms on gene signature identification.

TP53 mutations in Romanian patients with colorectal cancer

BACKGROUND

Colorectal cancer (CRC) has been ranked as the second most deadly cancer and the third most diagnosed cancer cases for the year 2020. Specifically for Romania, the number of CRC-related deaths in 2019 was estimated at 6307 people, with a standardized mortality rate of 33.8 per 100,000 inhabitants. Although the tumor protein 53 (TP53) gene is intensively studied, there are few data on TP53 mutations in Romanian CRC. Furthermore, since genetic alterations may show geographical differences, our study aimed to analyze the clinical status and TP53 somatic variation in Romanian CRC patients.

SUBJECTS AND METHODS

DNA from 40 randomly selected cases of CRC was extracted from formalin-fixed paraffin-embedded tissues and sequenced using direct Sanger sequencing techniques, and variants were annotated according to the recommendations of the Human Genome Variation Society. Novel variants were analyzed using MutationTaster2021 to predict their effects.

RESULTS

The mean age was 63.6 years (range 33-85 years) with a male to female ratio of 2.3. More than 45% (18/40) had an advanced cancer stage (≥ stage III). Mutations were found in 21/40 cases (52.5%), with one case having two mutations, giving a total of twenty-two mutations in the TP53 coding DNA. These mutations include 3 (13.6%) insertion-deletion mutations, two of which are novel frameshift mutations: c.165delT (in exon 4) and c.928_935dup (in exon 9), both of which are predicted to lead to nonsense-mediated mRNA decay and are classified as deleterious. The remaining 19 (86.36%) were substitution mutations: 1 nonsense and 18 (81.8%) missense mutations, with G > A (n = 7/19; 36.8%) and C > T (n = 6/19; 31.5%) transitions being the most common. The G > T transversion was found in 21.05% (4/19) of the substitution mutations.

CONCLUSION

We have described two novel frameshift mutations in TP53. The discovery of novel mutations following the efforts of The Cancer Genome Atlas and other large-scale cancer genome sequencing projects may be further evidence of the heterogeneous nature of mutations in cancer and may indicate that the identification of carcinogenic mutations is not yet saturated. Further sequencing is therefore needed, especially in less studied populations. Importantly, consideration of their geographical environment will shed light on population-specific carcinogenesis.

Combinatorial Network of Transcriptional and miRNA Regulation in Colorectal Cancer

Colorectal cancer is one of the leading causes of cancer-associated mortality across the worldwide. One of the major challenges in colorectal cancer is the understanding of the regulatory mechanisms of biological molecules. In this study, we aimed to identify novel key molecules in colorectal cancer by using a computational systems biology approach. We constructed the colorectal protein–protein interaction network which followed hierarchical scale-free nature. We identified TP53, CTNBB1, AKT1, EGFR, HRAS, JUN, RHOA, and EGF as bottleneck-hubs. The HRAS showed the largest interacting strength with functional subnetworks, having strong correlation with protein phosphorylation, kinase activity, signal transduction, and apoptotic processes. Furthermore, we constructed the bottleneck-hubs’ regulatory networks with their transcriptional (transcription factor) and post-transcriptional (miRNAs) regulators, which exhibited the important key regulators. We observed miR-429, miR-622, and miR-133b and transcription factors (EZH2, HDAC1, HDAC4, AR, NFKB1, and KLF4) regulates four bottleneck-hubs (TP53, JUN, AKT1 and EGFR) at the motif level. In future, biochemical investigation of the observed key regulators could provide further understanding about their role in the pathophysiology of colorectal cancer.

Overcoming Acquired Drug Resistance to Cancer Therapies through Targeted STAT3 Inhibition

Anti-neoplastic agents for cancer treatment utilize many different mechanisms of action and, when combined, can result in potent inhibition of cancer growth. Combination therapies can result in long-term, durable remission or even cure; however, too many times, these anti-neoplastic agents lose their efficacy due to the development of acquired drug resistance (ADR). In this review, we evaluate the scientific and medical literature that elucidate STAT3-mediated mechanisms of resistance to cancer therapeutics. Herein, we have found that at least 24 different anti-neoplastic agents-standard toxic chemotherapeutic agents, targeted kinase inhibitors, anti-hormonal agents, and monoclonal antibodies-that utilize the STAT3 signaling pathway as one mechanism of developing therapeutic resistance. Targeting STAT3, in combination with existing anti-neoplastic agents, may prove to be a successful therapeutic strategy to either prevent or even overcome ADR to standard and novel cancer therapies.

Modulation of Host Cell Signaling Pathways by Varicella-Zoster Virus

Host-pathogen interactions involve complex inside-out and outside-in signal transmission through critical cellular networks that dictate disease outcomes. The phosphoinositide 3-kinase (PI3K)/Akt pathway is a pivotal junction that regulates several cell functions, and phospho-Akt (pAkt) is often found to be constitutively active in cancer cells, similar to phospho-STAT3. In this chapter, we discuss the regulation of PI3K/Akt pathway in VZV infected cells and of other pathways including p53 which, unlike pAkt and pSTAT3, directs cells towards apoptosis. The fine spatio-temporal balance of activation of pro- and anti-apoptotic factors during VZV infection likely provides an optimum environment for the virus to replicate and cause disease in the human host.

Ethanolic extract of Origanum syriacum L. leaves exhibits potent anti-breast cancer potential and robust antioxidant properties

Background: Breast cancer (BC) is the second most common cancer overall. In women, BC is the most prevalent cancer and the leading cause of cancer-related mortality. Triple-negative BC (TNBC) is the most aggressive BC, being resistant to hormonal and targeted therapies. Hypothesis/Purpose: The medicinal plant Origanum syriacum L. is a shrubby plant rich in bioactive compounds and widely used in traditional medicine to treat various diseases. However, its therapeutic potential against BC remains poorly investigated. In the present study, we screened the phytochemical content of an ethanolic extract of O. syriacum (OSEE) and investigated its anticancer effects and possible underlying mechanisms of action against the aggressive and highly metastatic human TNBC cell line MDA-MB-231. Methods: MTT, trans-well migration, and scratch assays were used to assess cell viability, invasion, or migration, respectively. Antioxidant potential was evaluated in vitro using the DPPH radical-scavenging assay and levels of reactive oxygen species (ROS) were assessed in cells in culture using DHE staining. Aggregation assays were used to determine cell-cell adhesion. Flow cytometry was used to analyze cell cycle progression. Protein levels of markers of apoptosis (BCL-2, pro-Caspase3, p53), proliferation (p21, Ki67), cell migration, invasion, or adhesion (FAK, E-cadherin), angiogenesis (iNOS), and cell signaling (STAT3, p38) were determined by immunoblotting. A chorioallantoic Membrane (CAM) assay evaluated in ovo angiogenesis. Results: We demonstrated that OSEE had potent radical scavenging activity in vitro and induced the generation of ROS in MDA-MB-231 cells, especially at higher OSEE concentrations. Non-cytotoxic concentrations of OSEE attenuated cell proliferation and induced G₀/G₁ cell cycle arrest, which was associated with phosphorylation of p38 MAPK, an increase in the levels of tumor suppressor protein p21, and a decrease of proliferation marker protein Ki67. Additionally, only higher concentrations of OSEE were able to attenuate inhibition of proliferation induced by the ROS scavenger N-acetyl cysteine (NAC), indicating that the anti-proliferative effects of OSEE could be ROS-dependent. OSEE stimulated apoptosis and its effector Caspase-3 in MDA-MB-231 cells, in correlation with activation of the STAT3/p53 pathway. Furthermore, the extract reduced the migration and invasive properties of MDA-MB-231 cells through the deactivation of focal adhesion kinase (FAK). OSEE also reduced the production of inducible nitric oxide synthase (iNOS) and inhibited in ovo angiogenesis. Conclusion: Our findings reveal that OSEE is a rich source of phytochemicals and has robust anti-breast cancer properties that significantly attenuate the malignant phenotype of MD-MB-231 cells, suggesting that O. syriacum may not only act as a rich source of potential TNBC therapeutics but may also provide new avenues for the design of novel TNBC drugs.

The involvement of homeobox-C 4 in predicting prognosis and unraveling immune landscape across multiple cancers via integrated analysis

Background: There has been growing evidence that the aberrantly expressed Homeobox-C 4 (HOXC4) plays crucial roles in the development of some cancer types. However, it remains unclear as far as its expression patterns and prognostic significance are concerned, as is tumor immunity.

Methods: To investigate the expression levels and prognostic implications of HOXC4, multiple data sources were used in conjunction with quantitative real-time polymerase chain reaction (qRT-PCR) verification. Afterward, diverse immunological-related analyses, along with anti-cancer drug sensitivity, were performed in a number of cancer types. A further exploration of the underlying mechanisms of HOXC4 in tumorigenesis and immunity was carried out using the Gene Set Enrichment Analysis (GSEA) and the Gene Set Variation Analysis (GSVA).

Results: Based on extensive database mining, HOXC4 was ubiquitously expressed across 21 tumor cell lines and significantly higher than that of normal tissues in 21 tumor types. The outcome of survival analysis including overall survival (OS), disease-free interval (DFI), disease-specific survival (DSS) and progression-free interval (PFI) revealed that upregulation of HOXC4 expression in several cancers was associated with worse prognosis. Additionally, HOXC4 was observed to correlate closely with colon adenocarcinoma (COAD), head and neck squamous cell carcinoma (HNSC), lower grade glioma (LGG), liver hepatocellular carcinoma (LIHC), rectum adenocarcinoma (READ), and thyroid carcinoma (THCA) in terms of tumor immune cells infiltration. As a result of our comprehensive pan-cancer study, we have identified a significant link between the expression of HOXC4 and the efficacy of immunotherapy-related treatments, together with anti-cancer drug sensitivity. As a final note, HOXC4 was found to modulate multiple signaling pathways involved in tumorigenesis and immunity.

Conclusion: HOXC4 has been implicated in our study for the first time as an oncogene in cancers with a poor prognosis, potentially laying the groundwork for promising clinical biomarkers and immunotherapy approaches.

c-Myc Sustains Pancreatic Cancer Cell Survival and mutp53 Stability through the Mevalonate Pathway

It has been shown that wild-type (wt)p53 inhibits oncogene c-Myc while mutant (mut)p53 may transactivate it, with an opposite behavior that frequently occurs in the crosstalk of wt or mutp53 with molecules/pathways promoting carcinogenesis. Even if it has been reported that mutp53 sustains c-Myc, whether c-Myc could in turn influence mutp53 expression remains to be investigated. In this study, we found that pharmacological or genetic inhibition of c-Myc downregulated mutp53, impaired cell survival and increased DNA damage in pancreatic cancer cells. At the molecular level, we observed that c-Myc inhibition reduced the expression of mevalonate kinase (MVK), a molecule belonging to the mevalonate pathway that—according to previous findings—can control mutp53 stability, and thus contributes to cancer cell survival. In conclusion, this study unveils another criminal alliance between oncogenes, such as c-Myc and mutp53, that plays a key role in oncogenesis.

Energy-Stress-Mediated AMPK Activation Promotes GPX4-Dependent Ferroptosis through the JAK2/STAT3/P53 Axis in Renal Cancer

Energy stress is an unfavorable condition that tumor cells are often exposed to. Ferroptosis is considered an emerging target for tumor therapy. However, the role of ferroptosis in energy stress in renal cancer is currently unknown. In this study, we found that glucose deprivation significantly enhanced GPX4-dependent ferroptosis through AMPK activation. Further, AMPK activation suppressed GPX4 expression at the transcriptional level through the upregulation of P53 expression. Additionally, the inactivation of JAK2/STAT3 transcriptionally promoted P53 expression, thereby promoting AMPK-mediated GPX4-dependent ferroptosis. In conclusion, energy stress promotes AMPK-mediated GPX4-dependent erastin-induced ferroptosis in renal cancer through the JAK2/STAT3/P53 signaling axis.

The miR-590-3p/CFHR3/STAT3 signaling pathway promotes cell proliferation and metastasis in hepatocellular carcinoma

Accumulating evidence has indicated that Complement factor H-related 3 (CFHR3) plays an essential role in various diseases. However, the biological functions of CFHR3 in hepatocellular carcinoma (HCC) remain largely unclear. Therefore, we perform a further study on CFHR3 in HCC. In this article, we report the suppressive role of CFHR3 in the proliferation and metastasis of HCC cells. CFHR3 downregulation is closely associated with large (T3-T4) HCC, tumor recurrence, and advanced (stage III-IV) clinical stage, functioning as an independent factor for the prognoses of HCC patients. Knockdown of CFHR3 promotes proliferation, migration, and invasion of HCC cells. Mechanistically, downregulation of CFHR3 is induced by miR-590-3p binding to the 3’ untranslated region (UTR) of CFHR3. CFHR3 downregulation promotes the phosphorylation of STAT3 protein, thereby suppressing p53 expression. The promotional effect upon downregulation of CFHR3 induced by CFHR3 stable knockdown or miR-590-3p on HCC cell malignant phenotypes is attenuated by STAT3 inhibitor, S3I-201. In conclusion, our results reveal that CFHR3 is a protective biomarker for HCC patients, and targeting the miR-590-3p/CFHR3/p-STAT3/p53 signaling axis provides a promising strategy for HCC therapeutics.

Forced Overexpression of Signal Transducer and Activator of Transcription 3 (STAT3) Activates Yes-Associated Protein (YAP) Expression and Increases the Invasion and Proliferation Abilities of Small Cell Lung Cancer (SCLC) Cells

Background: We sought to investigate the interaction between signal transducer and activator of transcription 3 (STAT3) and the Yes-associated protein (YAP) signaling pathway in human small cell lung cancer (SCLC) cells. Methods: The STAT3-overexpressing SCLC cell lines H146 and H446 were established by plasmid DNA transfection for in vitro and in vivo experiments. Results: Overexpression of STAT3 increased YAP protein expression in H146 and H446 cells. STAT3 overexpression significantly increased YAP mRNA expression and the mRNA expression of the YAP signaling downstream genes CTGF and CYR61 in H146 and H446 cells (p < 0.05). We showed that STAT3 overexpression promoted EMT (epithelial−mesenchymal transition) with increased matrix metalloproteinase (MMP)-2 and MMP9 expression. Transwell assays showed that STAT3 overexpression increased the invasion ability of H146 and H446 cells. In addition, STAT3-overexpressing H146 cells grew significantly more rapidly than control H146 cells in the xenograft mouse model (p < 0.05). Immunohistochemistry (IHC) staining and Western blotting (WB) showed that STAT3-overexpressing H146 tumors had increased p-STAT3 and YAP staining and protein expression compared with control tumors. Increased EMT was also observed in STAT3-overexpressed xenograft tumors. Conclusions: The results of our study suggest that the overexpression of STAT3 promotes SCLC EMT, invasion, and proliferation through the activation of the YAP signaling pathway.

STAT3-EMT axis in tumors: modulation of cancer metastasis, stemness and therapy response

Epithelial-to-mesenchymal transition (EMT) mechanism is responsible for metastasis of tumor cells and their spread to various organs and tissues of body, providing undesirable prognosis. In addition to migration, EMT increases stemness and mediates therapy resistance. Hence, pathways involved in EMT regulation should be highlighted. STAT3 is an oncogenic pathway that can elevate growth rate and migratory ability of cancer cells and induce drug resistance. The inhibition of STAT3 signaling impairs cancer progression and promotes chemotherapy-mediated cell death. Present review focuses on STAT3 and EMT interaction in modulating cancer migration. First of all, STAT3 is an upstream mediator of EMT and is able to induce EMT-mediated metastasis in brain tumors, thoracic cancers and gastrointestinal cancers. Therefore, STAT3 inhibition significantly suppresses cancer metastasis and improves prognosis of patients. EMT regulators such as ZEB1/2 proteins, TGF-β, Twist, Snail and Slug are affected by STAT3 signaling to stimulate cancer migration and invasion. Different molecular pathways such as miRNAs, lncRNAs and circRNAs modulate STAT3/EMT axis. Furthermore, we discuss how STAT3 and EMT interaction affects therapy response of cancer cells. Finally, we demonstrate targeting STAT3/EMT axis by anti-tumor agents and clinical application of this axis for improving patient prognosis.

Importance of STAT3 signalling in cancer, metastasis and therapeutic interventions

The Signal Transducer and Activator of Transcription 3 (STAT3) protein is encoded on chromosome 17q21. The SH2 and the DNA binding domains are critical structural components of the protein, together with tyrosine and serine residues that initiate phosphorylation. STAT3 interacts with DNA directly and functions in cells as both a signal transducer and a transcription factor. Its cytoplasmic activation results in dimerisation and nuclear translocation, where it is involved in the transcription of a large number of target genes. STAT3 is hyperactive in cancer cells as a result of upstream STAT3 mutations or enhanced cytokine production in the tumour environment. The STAT3 signalling pathway promotes many hallmarks of carcinogenesis and metastasis, including enhanced cell proliferation and survival, as well as migration and invasion into the extracellular matrix. Recent investigations into novel STAT3-based therapies describe a range of innovative approaches, such as the use of novel oligonucleotide drugs. These limit STAT3 binding to its target genes by attaching to SH2 and DNA-binding domains. Yet, despite these significant steps in understanding the underpinning mechanisms, there are currently no therapeutic agents that addresses STAT3 signalling in a clinically relevant manner.

Deoxyelephantopin and Its Isomer Isodeoxyelephantopin: Anti-Cancer Natural Products with Multiple Modes of Action

Cancer is a leading cause of morbidity and mortality worldwide. The development of cancer involves aberrations in multiple pathways, representing promising targets for anti-cancer drug discovery. Natural products are regarded as a rich source for developing anti-cancer therapies due to their unique structures and favorable pharmacology and toxicology profiles. Deoxyelephantopin and isodeoxyelephantopin, sesquiterpene lactone compounds, are major components of Elephantopus scaber and Elephantopus carolinianus, which have long been used as traditional medicines to treat multiple ailments, including liver diseases, diabetes, bronchitis, fever, diarrhea, dysentery, cancer, renal disorders, and inflammation-associated diseases. Recently, deoxyelephantopin and isodeoxyelephantopin have been extensively explored for their anti-cancer activities. This review summarizes and discusses the anti-cancer activities of deoxyelephantopin and isodeoxyelephantopin, with an emphasis on their modes of action and molecular targets. Both compounds disrupt several processes involved in cancer progression by targeting multiple signaling pathways deregulated in cancers, including cell cycle and proliferation, cell survival, autophagy, and invasion pathways. Future directions of research on these two compounds towards anti-cancer drug development are discussed.

Elaeagnus angustifolia Plant Extract Induces Apoptosis via P53 and Signal Transducer and Activator of Transcription 3 Signaling Pathways in Triple-Negative Breast Cancer Cells

Elaeagnus angustifolia (EA) is used as an alternative medicine in the Middle East to manage numerous human diseases. We recently reported that EA flower extract inhibits cell proliferation and invasion of human oral and HER2-positive breast cancer cells. Nevertheless, the outcome of EA extract on triple-negative breast cancer (TNBC) cells has not been explored yet. We herein investigate the effect of the aqueous EA extract (100 and 200 μl/ml) on two TNBC cell lines (MDA-MB-231 and MDA-MB-436) for 48 h and explore its underlying molecular pathways. Our data revealed that EA extract suppresses cell proliferation by approximately 50% and alters cell-cycle progression of these two cancer cell lines. Additionally, EA extract induces cell apoptosis by 40–50%, accompanied by the upregulation of pro-apoptotic markers (Bax and cleaved caspase-8) and downregulation of the anti-apoptotic marker, Bcl-2. Moreover, EA extract inhibits colony formation compared to their matched control. More significantly, the molecular pathway analysis of EA-treated cells revealed that EA extract enhances p53 expression, while inhibiting the expression of total and phosphorylated Signal Transducer and Activator Of Transcription 3 (STAT3) in both cell lines, suggesting p53 and STAT3 are the main key players behind the biological events provoked by the extract in TNBC cells. Our findings implicate that EA flower extract may possess an important potential as an anticancer drug against TNBC.

Holistic View of ALK TKI Resistance in ALK-Positive Anaplastic Large Cell Lymphoma

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase expressed at early stages of normal development and in various cancers including ALK-positive anaplastic large cell lymphoma (ALK+ ALCL), in which it is the main therapeutic target. ALK tyrosine kinase inhibitors (ALK TKIs) have greatly improved the prognosis of ALK+ALCL patients, but the emergence of drug resistance is inevitable and limits the applicability of these drugs. Although various mechanisms of resistance have been elucidated, the problem persists and there have been relatively few relevant clinical studies. This review describes research progress on ALK+ ALCL including the application and development of new therapies, especially in relation to drug resistance. We also propose potential treatment strategies based on current knowledge to inform the design of future clinical trials.

Activation of ABCC Genes by Cisplatin Depends on the CoREST Occurrence at Their Promoters in A549 and MDA-MB-231 Cell Lines

Simple Summary

Cisplatin resistance is a common issue that affects patients with a variety of cancers who are treated with this drug. In this research, we present a novel epigenetic mechanism that controls the expression of ABC-family transporters, which are involved in multidrug resistance. We report that the CoREST complex may be a key factor that determines the transcription of ABC transporters in non-small cell lung and triple-negative breast cancer cells (A549 and MDA-MB-231, respectively) treated with cisplatin. By occupying gene promoters, this multi-subunit repressor prevents both an EP300-dependent increase in ABCC transcription induced by the alkylating drug and gene overexpression in cisplatin-resistant phenotypes. Moreover, the CoREST-free promoter of ABCC10 responds to cisplatin with EP300-mediated gene activation, which is only possible in p53-proficient cells.

Abstract

Although cisplatin-based therapies are common among anticancer approaches, they are often associated with the development of cancer drug resistance. This phenomenon is, among others, caused by the overexpression of ATP-binding cassette, membrane-anchored transporters (ABC proteins), which utilize ATP to remove, e.g., chemotherapeutics from intracellular compartments. To test the possible molecular basis of increased expression of ABCC subfamily members in a cisplatin therapy mimicking model, we generated two cisplatin-resistant cell lines derived from non-small cell lung cancer cells (A549) and triple-negative breast cancer cells (MDA-MB-231). Analysis of data for A549 cells deposited in UCSC Genome Browser provided evidence on the negative interdependence between the occurrence of the CoREST complex at the gene promoters and the overexpression of ABCC genes in cisplatin-resistant lung cancer cells. Pharmacological inhibition of CoREST enzymatic subunits—LSD1 and HDACs—restored gene responsiveness to cisplatin. Overexpression of CoREST-free ABCC10 in cisplatin-resistant phenotypes was caused by the activity of EP300 that was enriched at the ABCC10 promoter in drug-treated cells. Cisplatin-induced and EP300-dependent transcriptional activation of ABCC10 was only possible in the presence of p53. In summary, the CoREST complex prevents the overexpression of some multidrug resistance proteins from the ABCC subfamily in cancer cells exposed to cisplatin. p53-mediated activation of some ABCC genes by EP300 occurs once their promoters are devoid of the CoREST complex.

IL-6/STAT3 Is a Promising Therapeutic Target for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumor of which the occurrence and development, the tumorigenicity of HCC is involving in multistep and multifactor interactions. Interleukin-6 (IL-6), a multifunctional inflammatory cytokine, has increased expression in HCC patients and is closely related to the occurrence of HCC and prognosis. IL-6 plays a role by binding to the IL-6 receptor (IL-6R) and then triggering the Janus kinase (JAK) associated with the receptor, stimulating phosphorylation and activating signal transducer and activator of transcription 3 (STAT3) to initiate downstream signals, participating in the processes of anti-apoptosis, angiogenesis, proliferation, invasion, metastasis, and drug resistance of cancer cells. IL-6/STAT3 signal axes elicit an immunosuppressive in tumor microenvironment, it is important to therapy HCC by blocking the IL-6/STAT3 signaling pathway. Recent, some inhibitors of IL-6/STAT3 have been development, such as S31-201 or IL-6 neutralizing monoclonal antibody (IL-6 mAb), Madindoline A (Inhibits the dimerization of IL-6/IL-6R/gpl30 trimeric complexes), C188-9 and Curcumin (Inhibits STAT3 phosphorylation), etc. for treatment of cancers. Overall, consideration of the IL-6/STAT3 signaling pathway, and its role in the carcinogenesis and progression of HCC will contribute to the development of potential drugs for targeting treatment of liver cancer.

Current status of intratumour microbiome in cancer and engineered exogenous microbiota as a promising therapeutic strategy

Research on the relationship between microbiome and cancer has made significant progress in the past few decades. It is now known that the gut microbiome has multiple effects on tumour biology. However, the relationship between intratumoral bacteria and cancers remains unclear. Growing evidence suggests that intratumoral bacteria are important components of the microenvironment in several types of cancers. Furthermore, several studies have demonstrated that intratumoral bacteria may directly influence tumorigenesis, progression and responses to treatment. Limited studies have been conducted on intratumoral bacteria, and using intratumoral bacteria to treat tumours remains a challenge. Bacteria have been studied as anticancer therapeutics since the 19th century when William B. Coley successfully treated patients with inoperable sarcomas using Streptococcus pyogenes. With the development of synthetic biological approaches, several bacterial species have been genetically engineered to increase their applicability for cancer treatment. Genetically engineered bacteria for cancer therapy have unique properties compared to other treatment methods. They can specifically accumulate within tumours and inhibit cancer growth. In addition, genetically engineered bacteria may be used as a vector to deliver antitumour agents or combined with radiation and chemotherapy to synergise the effectiveness of cancer treatment. However, various problems in treating tumours with genetically engineered bacteria need to be addressed. In this review, we focus on the role of intratumoral bacteria on tumour initiation, progression and responses to chemotherapy or immunotherapy. Moreover, we summarised the recent progress in the treatment of tumours with genetically engineered bacteria.

Bavachin Induces Ferroptosis through the STAT3/P53/SLC7A11 Axis in Osteosarcoma Cells

Ferroptosis is a new form of regulated cell death, which is mediated by intracellular iron. Although it is reported that bavachin has antitumour effects on several tumour cells and prompts the reactive oxygen species (ROS) generation, it is unclear whether ferroptosis can be induced by bavachin in osteosarcoma (OS) cells. In this study, we found that bavachin inhibits the viability of MG63 and HOS OS cell lines along with an increase in the ferrous iron level, ROS accumulation, malondialdehyde overexpression, and glutathione depletion. Moreover, iron chelators (deferoxamine), antioxidants (Vit E), and ferroptosis inhibitors (ferrostatin-1 and liproxstatin-1) reverse bavachin-induced cell death. Bavachin also altered the mitochondrial morphology of OS cells, leading to smaller mitochondria, higher density of the mitochondrial membrane, and reduced mitochondrial cristae. Further investigation showed that bavachin upregulated the expression of transferrin receptor, divalent metal transporter-1, and P53, along with downregulating the expression of ferritin light chain, ferritin heavy chain, p-STAT3 (705), SLC7A11, and glutathione peroxidase-4 in OS cells. More importantly, STAT3 overexpression, SLC7A11 overexpression, and pretreatment with pifithrin-α (P53 inhibitor) rescued OS cell ferroptosis induced by bavachin. The results show that bavachin induces ferroptosis via the STAT3/P53/SLC7A11 axis in OS cells.

Interplay of Epidermal Growth Factor Receptor and Signal Transducer and Activator of Transcription 3 in Prostate Cancer: Beyond Androgen Receptor Transactivation

Prostate cancer (PCa) is one of the most common cancers in the world and causes thousands of deaths every year. Conventional therapy for PCa includes surgery and androgen deprivation therapy (ADT). However, about 10-20% of all PCa cases relapse; there is also the further development of castration resistant adenocarcinoma (CRPC-Adeno) or neuroendocrine (NE) PCa (CRPC-NE). Due to their androgen-insensitive properties, both CRPC-Adeno and CRPC-NE have limited therapeutic options. Accordingly, this study reveals the inductive mechanisms of CRPC (for both CRPC-Adeno and CRPC-NE) and fulfils an urgent need for the treatment of PCa patients. Although previous studies have illustrated the emerging roles of epidermal growth factor receptors (EGFR), signal transducer, and activator of transcription 3 (STAT3) signaling in the development of CRPC, the regulatory mechanisms of this interaction between EGFR and STAT3 is still unclear. Our recent studies have shown that crosstalk between EGFR and STAT3 is critical for NE differentiation of PCa. In this review, we have collected recent findings with regard to the involvement of EGFR and STAT3 in malignancy progression and discussed their interactions during the development of therapeutic resistance for PCa.

Recent Advances in Oligonucleotide Therapeutics in Oncology

Cancer is one of the leading causes of death worldwide. Conventional therapies, including surgery, radiation, and chemotherapy have achieved increased survival rates for many types of cancer over the past decades. However, cancer recurrence and/or metastasis to distant organs remain major challenges, resulting in a large, unmet clinical need. Oligonucleotide therapeutics, which include antisense oligonucleotides, small interfering RNAs, and aptamers, show promising clinical outcomes for disease indications such as Duchenne muscular dystrophy, familial amyloid neuropathies, and macular degeneration. While no approved oligonucleotide drug currently exists for any type of cancer, results obtained in preclinical studies and clinical trials are encouraging. Here, we provide an overview of recent developments in the field of oligonucleotide therapeutics in oncology, review current clinical trials, and discuss associated challenges.