Role of STAT3 in lung cancer

Panduratin A from Boesenbergia rotunda Effectively Inhibits EGFR/STAT3/Akt Signaling Pathways, Inducing Apoptosis in NSCLC Cells with Wild-Type and T790M Mutations in EGFR

Non-small cell lung cancer (NSCLC) is a challenging disease, with the epidermal growth factor receptor (EGFR) being a key target for new, effective treatments crucial for the signaling pathways regulating cancer cell survival. Targeting EGFR-mediated signaling offers promising strategies to improve NSCLC therapies, particularly in overcoming resistance in EGFR-mutant lung cancer. In this study, we investigated the anticancer effects of panduratin A, a naturally occurring flavonoid from Boesenbergia rotunda, on human NSCLC cell lines expressing both wild-type EGFR (A549) and mutant EGFR (H1975) using in vitro experiments and molecular docking approaches. Cytotoxicity screening revealed that panduratin A exhibits potent effects on both A549 (IC50 of 6.03 ± 0.21 µg/mL) and H1975 (IC50 of 5.58 ± 0.15 µg/mL) cell lines while demonstrating low toxicity to normal MRC5 lung cells (12.96 ± 0.36 µg/mL). Furthermore, western blotting and flow cytometric analyses indicated that panduratin A induces apoptosis by inhibiting p-EGFR and its downstream effectors, p-STAT3 and p-Akt, in lung cancer cells. Additionally, the docking study showed lower binding energy between panduratin A and the target proteins, comparable to that of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs). The ADMET prediction also highlighted panduratin A's exceptional drug-like properties. This study concludes that panduratin A shows significant promise as an anti-lung cancer candidate for NSCLC, offering an economical and effective strategy.

Overexpression of IL-6 and STAT3 may provide new insights into ovine pulmonary adenocarcinoma development

BACKGROUND

Ovine pulmonary adenocarcinoma (OPA) is caused by Jaagsiekte sheep retrovirus (JSRV) and is considered an important potential animal model for human lung cancer. The precise mechanisms of OPA oncogenesis are still uncertain. The transcription factor signal transducer and activator of transcription 3 (STAT3) is activated by interleukin-6 (IL-6) in many cancers, but this aspect is unknown in OPA. We therefore aimed to evaluate the expression of IL-6 and STAT3 in OPA for its potential role in pulmonary carcinogenesis.

RESULTS

Lung tissues from 9 grossly normal and JRSV-negative sheep and 20 cases of JSRV-positive OPA sheep were included in the study. Tissue samples were stained with antibodies against IL-6, STAT3, and JSRV-MA. IL-6 and STAT3 were further quantified in both groups using Western Blot (WB). Immunohistochemically, IL‑6 was expressed in stromal, inflammatory, and epithelial cells in all cases of OPA, while STAT3 immunoexpression was restricted to epithelial cells. In the OPA group, the percentage of immunolabelled cells for STAT3 accounted for a mean value of 96%. Using the H-SCORE method, 95% of cases were considered positive for STAT3 expression. Control tissues showed multifocal and weak immunoexpression for both markers. Using WB analyses, a highly significant amount of both IL-6 (p = 0.0078) and STAT3 (p < 0.0001) proteins were present in lung neoplasms, by comparison to the control lungs.

CONCLUSIONS

Our data showed overexpression of IL-6 and STAT3 in lung tissues from OPA compared to lungs from JSRV-negative sheep. These results suggest a potential role of IL6-STAT3 in OPA carcinogenesis.

The Role of Pentacyclic Triterpenoids in Non-Small Cell Lung Cancer: The Mechanisms of Action and Therapeutic Potential

Lung cancer remains a major global health problem because of its high cancer-related mortality rate despite advances in therapeutic approaches. Non-small cell lung cancer (NSCLC), a major subtype of lung cancer, is more amenable to surgical intervention in its early stages. However, the prognosis for advanced NSCLC remains poor, owing to limited treatment options. This underscores the growing need for novel therapeutic strategies to complement existing treatments and improve patient outcomes. In recent years, pentacyclic triterpenoids, a group of natural compounds, have emerged as promising candidates for cancer therapy due to their anticancer properties. Pentacyclic triterpenoids, such as lupeol, betulinic acid, betulin, oleanolic acid, ursolic acid, glycyrrhetinic acid, glycyrrhizin, and asiatic acid, have demonstrated the ability to inhibit cell proliferation and angiogenesis, induce apoptosis, suppress metastasis, and modulate inflammatory and immune pathways in NSCLC cell line models. These compounds exert their effects by modulating important signaling pathways such as NF-κB, PI3K/Akt, and MAPK. Furthermore, advances in drug delivery technologies such as nanocarriers and targeted delivery systems have improved the bioavailability and therapeutic efficacy of triterpenoids. However, despite promising preclinical data, rigorous clinical trials are needed to verify their safety and efficacy. This review explores the role of triterpenoids in NSCLC and therapeutic potential in preclinical models, focusing on their molecular mechanisms of action.

Asparagus racemosus silver chloride nanoparticles and Kaempferia rotunda mediated silver/silver chloride nanoparticles inhibit human hepatocellular and lung cancer cell lines

Recently, we have reported that biogenic silver/silver chloride nanoparticles from Asparagus racemosus (A. racemosus-AgCl-NPs) and Kaempferia rotunda (K. rotunda-Ag/AgCl-NPs) inhibited different cancer cells by inducing apoptosis and several genes alteration. Here for the first time, we assessed the effects of these two nanoparticles on human lung (A549) and hepatocellular (SMMC-7721) carcinoma cell lines. A. racemosus-AgCl-NPs and K. rotunda-Ag/AgCl-NPs inhibited A549 cell growth with IC50 values of 22.7 and 59.7 μg/ml and the calculated IC50 values for SMMC-7721 cell were 89.3 and 126.3 μg/ml, respectively. A. racemosus-AgCl-NPs exerted higher cytotoxicity against HEK293T cells than doxorubicin and K. rotunda-Ag/AgCl-NPs. Both the nanoparticles induced apoptosis in A549 and SMMC-7721 cell lines. A significant rise of early apoptotic cells and late apoptotic cells was found for A549 cells after treatment with A. racemosus-AgCl-NPs and stained with FITC-annexin V/PI. Apoptosis in A549 cells was further confirmed by monitoring the alteration of the expression level of several genes using real-time PCR and cell cycle arrest by flowcytometry after treatment with A. racemosus-AgCl-NPs. The expression of STAT-3, TNFα, and EGFR genes was decreased with the increase of caspase-8, FAS, and FADD gene expression. G2/M cell cycle phase was arrested after treatment of A549 cells with A. racemosus-AgCl-NPs.

Prognostic value and molecular mechanisms of OAS1 in lung adenocarcinoma

BACKGROUND

The expression of 2'-5'-oligoadenylate synthetase 1 (OAS1) in lung cancer has been validated in numerous studies. However, the prognostic value of OAS1 expression in lung adenocarcinoma (LUAD) still remains unclear. This study aimed to reveal the prognostic value and associated molecular mechanisms of OAS1 expression in LUAD.

METHODS

Gene expression data of LUAD were extracted from online databases. Gene and protein expression levels of OAS1 in LUAD and normal samples were revealed, followed by prognostic analysis of OAS1. Next, we conducted a thorough bioinformatics analysis to examine the enrichment of key functional and biological signaling pathways and their correlation with the abundance of immune cells. The independent prognoses, drug responses, and PPI networks associated with OAS1 were analyzed. OAS1 expression was evaluated in LUAD tissues and cell lines. OAS1 was knocked down by siRNA transfection, followed by CCK8, colony formation, and wound-healing assays.

RESULTS

Gene and protein expression levels of OAS1 in LUAD samples were significantly higher than those in normal samples (all P < 0.05). OAS1 stimulation were correlated with poor prognosis, lymph node metastasis, advanced tumor stage, immune cells, and immunomodulators. The prognostic value of OAS1 in LUAD was determined via univariate regression analysis. In total, 10 OAS1-associated genes were revealed via PPI analysis of OAS1, which were primarily enriched in functions, such as the negative regulation of viral genome replication. Transcriptional analysis revealed several OAS1-related interactions, including STAT3-miR-21-OAS1. STAT3 was overexpressed and miR-21 was expressed in LUAD cells. Upregulation of OAS1 protein was determined in LUAD tissues and cell lines. OAS1 knockdown significantly reduced proliferation and migration of LUAD cells.

CONCLUSIONS

OAS1 overexpression influenced survival and immune cell infiltration in patients with LUAD, which might be a potential prognostic gene for LUAD. Moreover, OAS1 contributed to LUAD progression by participating in STAT3-miR-21-OAS1 axis.

Antiproliferative, apoptotic and anti-inflammatory potential of 5H-benzo[h]thiazolo[2,3-b]quinazoline analogues: Novel series of anticancer compounds

Lung cancer (LC) is the most common cancer in males. As per GLOBOCAN 2020, 8.1 % of deaths and 5.9 % of cases of LC were reported in India. Our laboratory has previously reported the significant anticancer potential of 5H-benzo[h]thiazolo[2,3-b]quinazoline analogues. In this study, we have explored the anticancer potential of 7A {4-(6,7-dihydro-5H-benzo[h]thiazolo[2,3-b]quinazolin-7-yl)phenol} and 9A {7-(4-chlorophenyl)-9-methyl-6,7-dihydro-5H-benzo[h]thiazolo[2,3-b]quinazoline}by using in-vitro and in-vivo models of LC. In this study, we investigated the antiproliferative potential of quinazoline analogues using A549 cell line to identify the best compound of the series. The in-vitro and molecular docking studies revealed 7A and 9A compounds as potential analogues. We also performed acute toxicity study to determine the dose. After that, in-vivo studies using urethane-induced LC in male albino Wistar rats carried out further physiological, biochemical, and morphological evaluation (SEM and H&E) of the lung tissue. We have also evaluated the antioxidant level, inflammatory, and apoptotic marker expressions. 7A and 9A did not demonstrate any signs of acute toxicity. Animals treated with urethane showed a significant upregulation of oxidative stress. However, treatment with 7A and 9A restored antioxidant markers near-normal levels. SEM and H&E staining of the lung tissue demonstrated recovered architecture after treatment with 7A and 9A. Both analogues significantly restore inflammatory markers to normal level and upregulate the intrinsic apoptosis protein expression in the lung tissue. These experimental findings demonstrated the antiproliferative potential of the synthetic analogues 7A and 9A, potentially due to their anti-inflammatory and apoptotic properties.

Antiproliferative effect of indeno[1,2-d]thiazolo[3,2-a]pyrimidine analogues on IL-6 mediated STAT3 and role of the apoptotic pathway in albino Wistar rats of ethyl carbamate-induced lung carcinoma: In-silico, In-vitro, and In-vivo study

Lung cancer (LC) ranks second most prevalent cancer in females after breast cancer and second in males after prostate cancer. Based on the GLOBOCAN 2020 report, India represented 5.9% of LC cases and 8.1% of deaths caused by the disease. Several clinical studies have shown that LC occurs because of biological and morphological abnormalities and the involvement of altered level of antioxidants, cytokines, and apoptotic markers. In the present study, we explored the antiproliferative activity of indeno[1,2-d]thiazolo[3,2-a]pyrimidine analogues against LC using in-vitro, in-silico, and in-vivo models. In-vitro screening against A549 cells revealed compounds 9B (8-methoxy-5-(3,4,5-trimethoxyphenyl)-5,6-dihydroindeno[1,2-d]thiazolo[3,2-a]pyrimidine) and 12B (5-(4-chlorophenyl)-5,6-dihydroindeno[1,2-d]thiazolo[3,2-a]pyrimidine) as potential pyrimidine analogues against LC. Compounds 9B and 12B were docked with different molecular targets IL-6, Cyt-C, Caspase9, and Caspase3 using AutoDock Vina 4.1 to evaluate the binding affinity. Subsequently, in-vivo studies were conducted in albino Wistar rats through ethyl-carbamate (EC)- induced LC. 9B and 12B imparted significant effects on physiological (weight variation), and biochemical (anti-oxidant [TBAR's, SOD, ProC, and GSH), lipid (TC, TG, LDL, VLDL, and HDL)], and cytokine (IL-2, IL-6, IL-10, and IL-1β) markers in EC-induced LC in albino Wistar rats. Morphological examination (SEM and H&E) and western blotting (IL-6, STAT3, Cyt-C, BAX, Bcl-2, Caspase3, and caspase9) showed that compounds 9B and 12B had antiproliferative effects. Accordingly, from the in-vitro, in-silico, and in-vivo experimental findings, we concluded that 9B and 12B have significant antiproliferative potential and are potential candidates for further evaluation to meet the requirements of investigation of new drug application.

Effects of multi-walled carbon nanotubes on message and Micro-RNA in human lung BEAS-2B cells

Multi-walled Carbon nanotubes (MWCNTs) lack sufficient quality cytotoxicity, toxicity, genotoxicity and genomic data on which to make environmental and regulatory decisions. Therefore, we did a multidisciplinary in vitro study of 3 MWCNTs in human lung cells (BEAS-2B) with the following endpoints: cytotoxicity, DNA damage, reactive oxygen and nitrogen species, lipid peroxidation and mRNA and microRNA expression analyses. The MWCNTs were either unfunctionalized or functionalized with either -OH or -COOH. Doses studied ranged from 0.3 to 100 ug/ml and were exposed to a human lung cell line in vitro for 72 h., with genomic studies being done from 30 ug/ml downward. Some of the genomic pathways that were altered by MWCNT exposure were NRF2 mediated oxidative stress response, DNA damage repair, nuclear excision repair, base excision repair, mitochondrial dysfunction, oxidative phosphorylation, HIF1α signaling, unfolded protein response, protein ubiquitination, ferroptosis and sirtuin signaling pathways. The data suggested that OH functionalized MWCNT caused more and larger gene/microRNA changes, followed by COOH functionalized MWCNT and unfunctionalized MWCNT being the least biologically active. From microRNA target filter analysis, there were altered signaling hubs. MYC is the only hub that altered by all 3 MWCNTs. Signaling hubs that are common to OH and COOH functionalized MWCNTs are GRB2, AR, TP63 and AGO2. The signaling hubs that were only present in OH functionalized MWCNTs are TP53, STAT3 and BRCA1. These signaling pathways and hubs we found in vitro correlated well with the published in vivo pathological effects like oxidative stress DNA damage, inflammation and cancer in MWCNTs treated mice.

Interplay between signal transducers and activators of transcription (STAT) proteins and cancer: involvement, therapeutic and prognostic perspective

Signal transducers and activators of transcription or STAT are proteins that consist of various transcription factors that are responsible for activating genes regarding cell proliferation, differentiation, and apoptosis. They commonly activate several cytokine, growth, or hormone factors via the JAK-STAT signaling pathway by tyrosine phosphorylation which are responsible for giving rise to numerous immune responses. Mutations within the Janus-Kinases (JAKs) or the STATs can set off the commencement of various malfunctions of the immune system of the body; carcinogenesis being an inevitable outcome. STATs are known to act as both oncogenes and tumor suppressor genes which makes it a hot topic of investigation. Various STATs related mechanisms are currently being investigated to analyze its potential of serving as a therapeutic base for numerous immune diseases and cancer; a deeper understanding of the molecular mechanisms involved in the signaling pathways can contribute to the same. This review will throw light upon each STAT member in causing cancer malignancies by affecting subsequent signaling pathways and its genetic and epigenetic associations as well as various inhibitors that could be used to target these pathways thereby devising new treatment options. The review will also focus upon the therapeutic advances made in cancers that most commonly affect people and discuss how STAT genes are identified as prognostic markers.

Oligonucleotide-Based Therapeutics for STAT3 Targeting in Cancer-Drug Carriers Matter

High expression and phosphorylation of signal transducer and transcription activator 3 (STAT3) are correlated with progression and poor prognosis in various types of cancer. The constitutive activation of STAT3 in cancer affects processes such as cell proliferation, apoptosis, metastasis, angiogenesis, and drug resistance. The importance of STAT3 in cancer makes it a potential therapeutic target. Various methods of directly and indirectly blocking STAT3 activity at different steps of the STAT3 pathway have been investigated. However, the outcome has been limited, mainly by the number of upstream proteins that can reactivate STAT3 or the relatively low specificity of the inhibitors. A new branch of molecules with significant therapeutic potential has emerged thanks to recent developments in the regulatory function of non-coding nucleic acids. Oligonucleotide-based therapeutics can silence target transcripts or edit genes, leading to the modification of gene expression profiles, causing cell death or restoring cell function. Moreover, they can reach untreatable targets, such as transcription factors. This review briefly describes oligonucleotide-based therapeutics that found application to target STAT3 activity in cancer. Additionally, this review comprehensively summarizes how the inhibition of STAT3 activity by nucleic acid-based therapeutics such as siRNA, shRNA, ASO, and ODN-decoy affected the therapy of different types of cancer in preclinical and clinical studies. Moreover, due to some limitations of oligonucleotide-based therapeutics, the importance of carriers that can deliver nucleic acid molecules to affect the STAT3 in cancer cells and cells of the tumor microenvironment (TME) was pointed out. Combining a high specificity of oligonucleotide-based therapeutics toward their targets and functionalized nanoparticles toward cell type can generate very efficient formulations.

Himalayan flora: targeting various molecular pathways in lung cancer

The fatal amplification of lung cancer across the globe and the limitations of current treatment strategies emphasize the necessity for substitute therapeutics. The incorporation of phyto-derived components in chemo treatment holds promise in addressing those challenges. Despite the significant progressions in lung cancer therapeutics, the complexities of molecular mechanism and pathways underlying this disease remain inadequately understood, necessitating novel biomarker targeting. The Himalayas, abundant in diverse plant varieties with established chemotherapeutic potential, presents a promising avenue for investigating potential cures for lung carcinoma. The vast diversity of phytocompounds herein can be explored for targeting the disease. This review delves into the multifaceted targets of lung cancer and explores the established phytochemicals with their specific molecular targets. It emphasizes comprehending the intricate pathways that govern effective therapeutic interventions for lung cancer. Through this exploration of Himalayan flora, this review seeks to illuminate potential breakthroughs in lung cancer management using natural compounds. The amalgamation of Himalayan plant-derived compounds with cautiously designed combined therapeutic approaches such as nanocarrier-mediated drug delivery and synergistic therapy offers an opportunity to redefine the boundaries of lung cancer treatment by reducing the drug resistance and side effects and enabling an effective targeted delivery of drugs. Furthermore, additional studies are obligatory to understand the possible derivation of natural compounds used in current lung cancer treatment from plant species within the Himalayan region.

Lung cancer treatment potential and limits associated with the STAT family of transcription factors

Lung cancer is one of the mortal cancers and the leading cause of cancer-related mortality, with a cancer survival rate of fewer than 5% in developing nations. This low survival rate can be linked to things like late-stage detection, quick postoperative recurrences in patients receiving therapy, and chemoresistance developing against various lung cancer treatments. Signal transducer and activator of transcription (STAT) family of transcription factors are involved in lung cancer cell proliferation, metastasis, immunological control, and treatment resistance. By interacting with specific DNA sequences, STAT proteins trigger the production of particular genes, which in turn result in adaptive and incredibly specific biological responses. In the human genome, seven STAT proteins have been discovered (STAT1 to STAT6, including STAT5a and STAT5b). Many external signaling proteins can activate unphosphorylated STATs (uSTATs), which are found inactively in the cytoplasm. When STAT proteins are activated, they can increase the transcription of several target genes, which leads to unchecked cellular proliferation, anti-apoptotic reactions, and angiogenesis. The effects of STAT transcription factors on lung cancer are variable; some are either pro- or anti-tumorigenic, while others maintain dual, context-dependent activities. Here, we give a succinct summary of the various functions that each member of the STAT family plays in lung cancer and go into more detail about the advantages and disadvantages of pharmacologically targeting STAT proteins and their upstream activators in the context of lung cancer treatment.

RNA profile of immuno-magnetically enriched lung cancer associated exosomes isolated from clinical samples

Exosomal cargo secreted from cancer cells has been associated with the development and progression of the tumour. Enriching clinically relevant tissue-specific exosomes may assist in the focused analysis of RNA molecules packaged during cancer. Therefore, this study utilized a rapid immunomagnetic enrichment approach for targeted isolation of lung cancer cell-derived exosomes from human plasma, followed by analysing their cargo RNA using high throughput sequencing. The total RNA purified from these immunomagnetically enriched exosomes provided adequate RNA quality for characterization through the Illumina platform. Differential expression analysis was performed between patients and healthy controls to study the altered exosomal RNA profile during lung cancer. Further, functional enrichment analysis was performed with the list of identified differentially expressed genes (DEGs). In total, 1383 mRNAs and 64 lncRNA were identified as differentially expressed between patient plasma exosomes than healthy controls (fold change > 2, P < 0.05). Kyoto encyclopaedia of Genes and Genomes (KEGG) pathway analysis revealed that the DEGs were mainly associated with cancer-related pathways, purine metabolism, calcium, and cGMP-PKG signalling pathways. In conclusion, the presented approach successfully demonstrated a novel strategy for focused disease-specific transcriptome analysis, which provides a feasible option for identifying disease-specific exosome biomarkers for detecting non-small lung cancer.

Identifying molecular targets of Aspiletrein-derived steroidal saponins in lung cancer using network pharmacology and molecular docking-based assessments

Lung cancer is one of the leading cancers and causes of cancer-related deaths worldwide. Due to its high prevalence and mortality rate, its clinical management remains a significant challenge. Previously, the in vitro anticancer activity of Aspiletrein A, a steroid and a saponin from Aspidistra letreae, against non-small cell lung cancer (NSCLC) cells was reported. However, the anticancer molecular mechanism of other Aspiletreins from A. letreae remains unknown. Using in silico network pharmacology approaches, the targets of Aspiletreins were predicted using the Swiss Target Prediction database. In addition, key mediators in NSCLC were obtained from the Genetic databases. The compound-target interacting networks were constructed using the STRING database and Cytoscape, uncovering potential targets, including STAT3, VEGFA, HSP90AA1, FGF2, and IL2. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis demonstrated that several pathways were highly relevant to cancer pathogenesis. Additionally, molecular docking and molecular dynamic analyses revealed the interaction between key identified targets and Aspiletreins, including hydrogen bonding and Van der Waals interaction. This study provides potential targets of Aspiletreins in NSCLC, and its approach of integrating network pharmacology, bioinformatics, and molecular docking is a powerful tool for investigating the mechanism of new drug targets on a specific disease.

NT157 exerts antineoplastic activity by targeting JNK and AXL signaling in lung cancer cells

Combination therapies or multi-targeted drugs have been pointed out as an option to prevent the emergence of resistant clones, which could make long-term treatment more effective and translate into better clinical outcomes for cancer patients. The NT157 compound is a synthetic tyrphostin that leads to long-term inhibition of IGF1R/IRS1-2-, STAT3- and AXL-mediated signaling pathways. Given the importance of these signaling pathways for the development and progression of lung cancer, this disease becomes an interesting model for generating preclinical evidence on the cellular and molecular mechanisms underlying the antineoplastic activity of NT157. In lung cancer cells, exposure to NT157 decreased, in a dose-dependent manner, cell viability, clonogenicity, cell cycle progression and migration, and induced apoptosis (p < 0.05). In the molecular scenario, NT157 reduced expression of IRS1 and AXL and phosphorylation of p38 MAPK, AKT, and 4EBP1. Besides, NT157 decreased expression of oncogenes BCL2, CCND1, MYB, and MYC and increased genes related to cellular stress and apoptosis, JUN, BBC3, CDKN1A, CDKN1B, FOS, and EGR1 (p < 0.05), favoring a tumor-suppressive cell signaling network in the context of lung cancer. Of note, JNK was identified as a key kinase for NT157-induced IRS1 and IRS2 phosphorylation, revealing a novel axis involved in the mechanism of action of the drug. NT157 also presented potentiating effects on EGFR inhibitors in lung cancer cells. In conclusion, our preclinical findings highlight NT157 as a putative prototype of a multitarget drug that may contribute to the antineoplastic arsenal against lung cancer.

Epigenetic underpinnings of inflammation: Connecting the dots between pulmonary diseases, lung cancer and COVID-19

Inflammation is an essential component of several respiratory diseases, such as chronic obstructive pulmonary disease (COPD), asthma and acute respiratory distress syndrome (ARDS). It is central to lung cancer, the leading cancer in terms of associated mortality that has affected millions of individuals worldwide. Inflammation and pulmonary manifestations are also the major causes of COVID-19 related deaths. Acute hyperinflammation plays an important role in the COVID-19 disease progression and severity, and development of protective immunity against the virus is greatly sought. Further, the severity of COVID-19 is greatly enhanced in lung cancer patients, probably due to the genes such as ACE2, TMPRSS2, PAI-1 and furin that are commonly involved in cancer progression as well as SAR-CoV-2 infection. The importance of inflammation in pulmonary manifestations, cancer and COVID-19 calls for a closer look at the underlying processes, particularly the associated increase in IL-6 and other cytokines, the dysregulation of immune cells and the coagulation pathway. Towards this end, several reports have identified epigenetic regulation of inflammation at different levels. Expression of several key inflammation-related cytokines, chemokines and other genes is affected by methylation and acetylation while non-coding RNAs, including microRNAs as well as long non-coding RNAs, also affect the overall inflammatory responses. Select miRNAs can regulate inflammation in COVID-19 infection, lung cancer as well as other inflammatory lung diseases, and can serve as epigenetic links that can be therapeutically targeted. Furthermore, epigenetic changes also mediate the environmental factors-induced inflammation. Therefore, a better understanding of epigenetic regulation of inflammation can potentially help develop novel strategies to prevent, diagnose and treat chronic pulmonary diseases, lung cancer and COVID-19.

RNF7 inhibits apoptosis and sunitinib sensitivity and promotes glycolysis in renal cell carcinoma via the SOCS1/JAK/STAT3 feedback loop

Background

RING finger protein 7 (RNF7) is a highly conserved protein that functions as an E3 ubiquitin ligase. RNF7 overexpression is indicated in multiple human cancers, but its role in renal cell carcinoma (RCC) and the mechanisms underlying how it regulates the initiation and progression of RCC have not been explored.

Methods

Bioinformatics analysis, quantitative reverse-transcription polymerase chain reaction (RT-PCR), and Western blot were conducted to determine the expression of RNF7 in RCC tissues and cell lines. Knockdown and overexpression experiments were performed to examine the effects of RNF7 on cell viability, apoptosis, and glycolysis in vitro and on tumor growth in nude mice in vivo.

Results

The elevated RNF7 expression in tumor tissues of patients with RCC was correlated with poor survival. RNF7 overexpression inhibited apoptosis and promoted glycolysis in vitro and increased tumor growth in vivo by activating the JAK/STAT3 signaling pathway by ubiquitination of SOCS1. Moreover, RNF7 overexpression affected the sensitivity of RCC cells to sunitinib. Finally, STAT3 activation was necessary for transcriptional induction of RNF7.

Conclusion

These results demonstrate that RNF7 inhibited apoptosis, promoted glycolysis, and inhibited sunitinib sensitivity in RCC cells via ubiquitination of SOCS1, thus activating STAT3 signaling. These suggest the potential for targeting the RNF7-SOCS1/JAK/STAT3 pathway for RCC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-022-00337-5.

Mechanisms of cancer stem cells drug resistance and the pivotal role of HMGA2

Nowadays, the focus of researchers is on perceiving the heterogeneity observed in a tumor. The researchers studied the role of a specific subset of cancer cells with high resistance to traditional treatments, recurrence, and unregulated metastasis. This small population of tumor cells that have stem-cell-like specifications was named Cancer Stem Cells (CSCs). The unique features that distinguish this type of cancer cell are self-renewing, generating clones of the tumor, plasticity, recurrence, and resistance to therapies. There are various mechanisms that contribute to the drug resistance of CSCs, such as CSCs markers, Epithelial mesenchymal transition, hypoxia, other cells, inflammation, and signaling pathways. Recent investigations have revealed the primary role of HMGA2 in the development and invasion of cancer cells. Importantly, HMGA2 also plays a key role in resistance to treatment through their function in the drug resistance mechanisms of CSCs and challenge it. Therefore, a deep understanding of this issue can provide a clearer perspective for researchers in the face of this problem.

Cell Type-Specific Roles of STAT3 Signaling in the Pathogenesis and Progression of K-ras Mutant Lung Adenocarcinoma

Simple Summary

Lung adenocarcinomas with mutations in the K-ras gene are hard to target pharmacologically and highly lethal. As a result, there is a need to identify other therapeutic targets that influence K-ras oncogenesis. One contender is STAT3, a transcription factor that is associated with K-ras mutations and aids tumor development and progression through tumor cell intrinsic and extrinsic mechanisms. In this review, we summarize the lung epithelial and infiltrating immune cells that express STAT3, the roles of STAT3 in K-ras mutant lung adenocarcinoma, and therapies that may be able to target STAT3.

Abstract

Worldwide, lung cancer, particularly K-ras mutant lung adenocarcinoma (KM-LUAD), is the leading cause of cancer mortality because of its high incidence and low cure rate. To treat and prevent KM-LUAD, there is an urgent unmet need for alternative strategies targeting downstream effectors of K-ras and/or its cooperating pathways. Tumor-promoting inflammation, an enabling hallmark of cancer, strongly participates in the development and progression of KM-LUAD. However, our knowledge of the dynamic inflammatory mechanisms, immunomodulatory pathways, and cell-specific molecular signals mediating K-ras-induced lung tumorigenesis is substantially deficient. Nevertheless, within this signaling complexity, an inflammatory pathway is emerging as a druggable target: signal transducer and activator of transcription 3 (STAT3). Here, we review the cell type-specific functions of STAT3 in the pathogenesis and progression of KM-LUAD that could serve as a new target for personalized preventive and therapeutic intervention for this intractable form of lung cancer.

Identification, Culture and Targeting of Cancer Stem Cells

Chemoresistance, tumor progression, and metastasis are features that are frequently seen in cancer that have been associated with cancer stem cells (CSCs). These cells are a promising target in the future of cancer therapy but remain largely unknown. Deregulation of pathways that govern stemness in non-tumorigenic stem cells (SCs), such as Notch, Wnt, and Hedgehog pathways, has been described in CSC pathogenesis, but it is necessary to conduct further studies to discover potential new therapeutic targets. In addition, some markers for the identification and characterization of CSCs have been suggested, but the search for specific CSC markers in many cancer types is still under development. In addition, methods for CSC cultivation are also under development, with great heterogeneity existing in the protocols used. This review focuses on the most recent aspects of the identification, characterization, cultivation, and targeting of human CSCs, highlighting the advances achieved in the clinical implementation of therapies targeting CSCs and remarking those potential areas where more research is still required.

Inflammation, Fibrosis and Cancer: Mechanisms, Therapeutic Options and Challenges

Uncontrolled inflammation is a salient factor in multiple chronic inflammatory diseases and cancers. In this review, we provided an in-depth analysis of the relationships and distinctions between uncontrolled inflammation, fibrosis and cancers, while emphasizing the challenges and opportunities of developing novel therapies for the treatment and/or management of these diseases. We described how drug delivery systems, combination therapy and the integration of tissue-targeted and/or pathways selective strategies could overcome the challenges of current agents for managing and/or treating chronic inflammatory diseases and cancers. We also recognized the value of the re-evaluation of the disease-specific roles of multiple pathways implicated in the pathophysiology of chronic inflammatory diseases and cancers-as well as the application of data from single-cell RNA sequencing in the success of future drug discovery endeavors.

Computational Analysis of Drug Resistance Network in Lung Adenocarcinoma

BACKGROUND

Lung cancer is a significant health problem and accounts for one-third of the deaths worldwide. A great majority of these deaths are caused by Non-Small Cell Lung Cancer (NSCLC). Chemotherapy is the leading treatment method for NSCLC, but resistance to chemotherapeutics is an important limiting factor that reduces the treatment success of patients with NSCLC.

OBJECTIVE

In this study, the relationship between differentially expressed genes affecting the survival of the patients, according to the bioinformatics analyses, and the mechanism of drug resistance is investigated for nonsmall cell lung adenocarcinoma patients.

METHODS

Five hundred thirteen patient samples were compared with fifty-nine control samples. The employed dataset was downloaded from The Cancer Genome Atlas (TCGA) database. The information on how the drug activity altered against the expressional diversification of the genes was extracted from the NCI-60 database. Four hundred thirty-three drugs with known Mechanism of Action (MoA) were analyzed. Diversifications of the activity of these drugs related to genes were considered based on nine lung cancer cell lines virtually. The analyses were performed using R programming language, GDCRNATools, rcellminer, and Cytoscape.

RESULTS

This work analyzed the common signaling pathways and expressional alterations of the proteins in these pathways associated with survival and drug resistance in lung adenocarcinoma. Deduced computational data demonstrated that proteins of EGFR, JNK/MAPK, NF-κB, PI3K /AKT/mTOR, JAK/STAT, and Wnt signaling pathways were associated with the molecular mechanism of resistance to anticancer drugs in NSCLC cells.

CONCLUSION

To understand the relationships between resistance to anticancer drugs and EGFR, JNK/MAPK, NF-κB, PI3K /AKT/mTOR, JAK/STAT, and Wnt signaling pathways is an important approach to design effective therapeutics for individuals with NSCLC adenocarcinoma.

Swertia chirayita suppresses the growth of non-small cell lung cancer A549 cells and concomitantly induces apoptosis via downregulation of JAK1/STAT3 pathway

Lung carcinoma is the leading cause of cancer-related mortalities worldwide, and present therapeutical interventions are not successful enough to treat this disease in many cases. Recent years have witnessed a surge in exploring natural compounds for their antiproliferative efficacy to expedite the characterization of novel anticancer chemotherapeutics. Swertia chirayita is a valued medicinal herb and possess intrinsic pharmaceutical potential. However, elucidation of its anticancer effects at molecular levels remains unclear and needs to be investigated. We assessed the anticancer and apoptotic efficacy of S. chirayita ethanolic extract (Sw-EtOH) on non-small cell lung cancer (NSCLC) A549 cells during this exploratory study. The results elucidated that S. chirayita extract induced toxic effects within lung cancer cells by ~1 fold during cytotoxicity and LDH release assay at a 400 μg/ml concentration. Sw-EtOH extract elevates the level of ROS, resulting in the disruption of Δψm and release of cytosolic cytochrome c by 3.15 fold. Activation of caspases-3, -8 & -9 also escalated by ~1 fold, which further catalyze the augmentation of PARP cleavage (~3 folds), resulting in a four-fold increase in Sw-EtOH induced apoptosis. The gene expression analysis further demonstrated that Sw-EtOH extracts inhibited JAK1/STAT3 signaling pathway by down-regulating the levels of JAK1 and STAT3 to nearly half a fold. Treatment of Sw-EtOH modulates the expression level of various STAT3 associated proteins, including Bcl-XL, Bcl-2, Mcl-1, Bax, p53, Fas, Fas-L, cyclinD1, c-myc, IL-6, p21 and p27 in NSCLC cells. Thus, our study provided a strong impetus that Sw-EtOH holds the translational potential of being further evaluated as efficient cancer therapeutics and a preventive agent for the management of NSCLC.

TR35 Exerts Anti-tumor Effects by Modulating Mitogen-Activated Protein Kinase and STAT3 Signaling in Lung Cancer Cells

Cancer is a complex disease extremely dependent on its microenvironment and is highly regulated by a variety of stimuli inside and outside the cell. Evidence suggests that active camel whey fraction (TR35) confer anti-tumor effects in non-small cell lung cancer (NSCLC). However, its exact mechanisms remain elusive. Here, we investigated the mechanisms underlying suppression of NSCLC cell growth and proliferation by TR35. Treatment of A549 and H1299 cells with TR35 suppressed their growth and enhanced apoptosis, as revealed by CCK-8, colony formation and flow cytometric analyses. We find that TR35 suppresses tumor growth in a xenograft nude mouse model without losses in body weight. RNA-seq and KEGG pathway analyses showed that the DEGs were enriched in mitogen-activated protein kinase (MAPK) and Jak-STAT signaling pathways. After test the key factors’ activity associated with these pathways by Immunohistochemical (IHC) staining and western blotting, the activation of JNK phosphorylation and inhibition of p38 and STAT3 phosphorylation was observed both in TR35 treated lung cancer cell and tumor tissue. Taken together, these results showed that TR35 play a significant role in the NSCLC progression in the tumor microenvironment via MAPK and Jak-STAT signaling, highlighting TR35 as a potential therapeutic agent against lung cancer.

The Role of Tumor Inflammatory Microenvironment in Lung Cancer

Lung cancer is the most common and fatal malignant tumor in the world. The tumor microenvironment (TME) is closely related to the occurrence and development of lung cancer, in which the inflammatory microenvironment plays an important role. Inflammatory cells and inflammatory factors in the tumor inflammatory microenvironment promote the activation of the NF-κB and STAT3 inflammatory pathways and the occurrence, development, and metastasis of lung cancer by promoting immune escape, tumor angiogenesis, epithelial-mesenchymal transition, apoptosis, and other mechanisms. Clinical and epidemiological studies have also shown a strong relationship among chronic infection, inflammation, inflammatory microenvironment, and lung cancer. The relationship between inflammation and lung cancer can be better understood through the gradual understanding of the tumor inflammatory microenvironment, which is advantageous to find more therapeutic targets for lung cancer.

EML4-ALK induces cellular senescence in mortal normal human cells and promotes anchorage-independent growth in hTERT-transduced normal human cells

BACKGROUND

Chromosomal inversions involving anaplastic lymphoma kinase (ALK) and echinoderm microtubule associated protein like 4 (EML4) generate a fusion protein EML4-ALK in non-small cell lung cancer (NSCLC). The understanding of EML4-ALK function can be improved by a functional study using normal human cells.

METHODS

Here we for the first time conduct such study to examine the effects of EML4-ALK on cell proliferation, cellular senescence, DNA damage, gene expression profiles and transformed phenotypes.

RESULTS

The lentiviral expression of EML4-ALK in mortal, normal human fibroblasts caused, through its constitutive ALK kinase activity, an early induction of cellular senescence with accumulated DNA damage, upregulation of p16INK4A and p21WAF1, and senescence-associated β-galactosidase (SA-β-gal) activity. In contrast, when EML4-ALK was expressed in normal human fibroblasts transduced with telomerase reverse transcriptase (hTERT), which is activated in the vast majority of NSCLC, the cells showed accelerated proliferation and acquired anchorage-independent growth ability in soft-agar medium, without accumulated DNA damage, chromosome aberration, nor p53 mutation. EML4-ALK induced the phosphorylation of STAT3 in both mortal and hTERT-transduced cells, but RNA sequencing analysis suggested that the different signaling pathways contributed to the different phenotypic outcomes in these cells. While EML4-ALK also induced anchorage-independent growth in hTERT-immortalized human bronchial epithelial cells in vitro, the expression of EML4-ALK alone did not cause detectable in vivo tumorigenicity in immunodeficient mice.

CONCLUSIONS

Our data indicate that the expression of hTERT is critical for EML4-ALK to manifest its in vitro transforming activity in human cells. This study provides the isogenic pairs of human cells with and without EML4-ALK expression.

Targeting CD47 Inhibits Tumor Development and Increases Phagocytosis in Oral Squamous Cell Carcinoma

BACKGROUND

Our previous work demonstrated upregulated CD47 in Oral Squamous Cell Carcinoma (OSCC).

OBJECTIVE

In the present study, we aimed to investigate the effects of CD47 on tumor cell development and phagocytosis in OSCC and elucidate the underlying mechanisms.

METHODS

The proliferation, apoptosis, migration, and invasion of oral cancer cells were analyzed after knocking down the expression of CD47. The effects of CD47 on tumor development were also evaluated using a murine model of OSCC. The involvement of CD47 in the phagocytosis of oral cancer cells was identified.

RESULTS

Cell proliferation was suppressed by knocking down the expression of CD47 in human OSCC cell line Cal-27 cells but there was no change in the apoptosis rate. Moreover, impaired expression of CD47 inhibited the migration and invasion of Cal-27 cells. Furthermore, we found that nude mice injected with CD47 knockeddown Cal-27 cells displayed decreased tumor volumes at week 9 compared to xenograft transplantations of blank Cal-27 cells. In addition, in vitro phagocytosis of Cal-27 cells by macrophages was significantly enhanced after the knockdown of CD47, which positively correlated with compromised STAT3/JAK2 signaling.

CONCLUSION

In summary, the knockdown of CD47 downregulated the development of OSCC and increased the phagocytosis of Cal-27 cells, indicating that CD47 might be a promising therapeutic target.

Acacetin and pinostrobin as a promising inhibitor of cancer-associated protein kinases

Protein kinases associated with cancer genes play vital role in angiogenesis, invasion, motility, proliferation, and survival. Therefore, cancer prevention/treatment, targeting kinases with phytochemicals could be a promising approach. Given potential of phytochemicals in modulating cancer-associated kinases, present study aims to find inhibitory prospects of selected flavonoids for cancer-chemoprevention/treatment. The molecular docking interaction analysis was done by exploring binding potential of flavonoids with kinases (PI3K, Akt, mTOR, EGFR, MAPK, MKK4, Fyn, ZAP-70, B-Raf, JAK-2, STAT-1, STAT-3, STAT-4, STAT-5, and VEGF) involved in various carcinogenesis phases. Among flavonoids acacetin showed highest binding-energy against JAK-2 following Fyn > VEGF > PI3K > MKK4 > MAPK > BRaf > STAT-5 > STAT-1 > STAT-4 whereas pinostrobin depicts higher binding-energy with JAK-2 followed by B-Raf > MKK4 > VEGF > PI3K > MAPK > STAT-1 > STAT-4 > STAT-5. Further, molecular-dynamic simulation revealed that pinostrobin interacted with JAK-2 protein with binding-energy of -25.068 ± 1.08 kJ/mol whereas acacetin interacted with both JAK-2 and Fyn with binding-energies of -23.466 ± 0.9508 kJ/mol and-8.935 ± 1.3108 kJ/mol respectively. High binding-energy, low inhibition-constant, and drug-likeness of acacetin and pinostrobin provide a clue for their usage as a JAK-2 inhibitor which could be useful for molecular/cell-target based in-vitro and in-vivo investigations.

Network Analysis Identifies Drug Targets and Small Molecules to Modulate Apoptosis Resistant Cancers

Programed cell death or apoptosis fails to induce cell death in many recalcitrant cancers. Thus, there is an emerging need to activate the alternate cell death pathways in such cancers. In this study, we analyzed the apoptosis-resistant colon adenocarcinoma, glioblastoma multiforme, and small cell lung cancers transcriptome profiles. We extracted clusters of non-apoptotic cell death genes from each cancer to understand functional networks affected by these genes and their role in the induction of cell death when apoptosis fails. We identified transcription factors regulating cell death genes and protein-protein interaction networks to understand their role in regulating cell death mechanisms. Topological analysis of networks yielded FANCD2 (ferroptosis, negative regulator, down), NCOA4 (ferroptosis, up), IKBKB (alkaliptosis, down), and RHOA (entotic cell death, down) as potential drug targets in colon adenocarcinoma, glioblastoma multiforme, small cell lung cancer phenotypes respectively. We also assessed the miRNA association with the drug targets. We identified tumor growth-related interacting partners based on the pathway information of drug-target interaction networks. The protein-protein interaction binding site between the drug targets and their interacting proteins provided an opportunity to identify small molecules that can modulate the activity of functional cell death interactions in each cancer. Overall, our systematic screening of non-apoptotic cell death-related genes uncovered targets helpful for cancer therapy.

CD43 (sialophorin) is involved in the induction of extracellular matrix remodeling and angiogenesis by lung cancer cells

Aberrant expression of CD43 in malignant tumors of nonhematopoietic origin such as those from lung, cervix, colon, and breast has been shown to correlate with poor prognosis, providing tumor cells with enhanced motility, anchorage-independent growth, and in vivo tumor size, while protecting the cells of NK lysis and apoptosis. To further characterize the role of CD43 in cell transformation, we tested whether interfering its expression modified the capacity of the A549 non-small cell lung cancer cells to secrete molecules contributing to malignancy. The proteomic analysis of the secretome of serum-starved A549 cells revealed that cells expressing normal levels of CD43 released significantly high levels of molecules involved in extracellular matrix organization, angiogenesis, platelet degranulation, collagen degradation, and inflammation, as compared to CD43 RNAi cells. This data reveals a novel and unexpected role for CD43 in lung cancer development, mainly in remodeling the tumor microenvironment.

Programmed death-ligand 1 expression level as a predictor of EGFR tyrosine kinase inhibitor efficacy in lung adenocarcinoma

BACKGROUND

The main objective of this study was to investigate the impact of programmed death-ligand 1 (PD-L1) expression on the efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) in patients with advanced non-small cell lung cancer (NSCLC).

METHODS

This study analyzed 108 patients with NSCLC who had received EGFR-TKI as first-line systemic treatment at Seoul National University Bundang Hospital and Seoul National University Hospital between December 2012 and October 2018. The National Cancer Center Research Institute (NCCRI) and The Cancer Genome Atlas (TCGA) datasets were analyzed to investigate the mechanisms underlying EGFR-TKI-resistance in tumors with high PD-L1 expression.

RESULTS

Among the 108 patients, 55, 37, and 16 had negative (PD-L1 Tumor proportion score <1%), weak (1-49%), and strong (≥50%) PD-L1 expression, respectively. Patients with strong PD-L1 expression had significantly shorter median progression-free survival (PFS; 7.07 months) than patients with weak (14.73 months, P<0.001) or negative (12.70 months, P=0.001) PD-L1 expression. After adjustment for covariates by Cox regression, PD-L1 expression remained a significant indicator of adverse prognosis. In EGFR-TKI-refractory patients, the frequency of T790M mutation and the PFS following treatment with third-generation EGFR-TKI and PD-1 antibody were similar in the three groups. TCGA and NCCRI database analysis showed that high PD-L1 expression in EGFR-mutated NSCLCs correlated with IL-6/JAK/STAT3 signaling and high MUC16 mutation frequency.

CONCLUSIONS

Strong PD-L1 expression in tumors might be a surrogate indicator of poor response to first-line EGFR-TKIs in NSCLC patients with sensitizing EGFR mutations, and may reflect a de novo resistance mechanism involving JAK-STAT signaling.

The Promising Effects of Astaxanthin on Lung Diseases

Astaxanthin (ASX) is a naturally occurring xanthophyll carotenoid. Both in vitro and in vivo studies have shown that it is a potent antioxidant with anti-inflammatory properties. Lung cancer is the leading cause of cancer death worldwide, whereas other lung diseases such as chronic obstructive pulmonary disease, emphysema, and asthma are of high prevalence. In the past decade, mounting evidence has suggested a protective role for ASX against lung diseases. This article reviews the potential role of ASX in protecting against lung diseases, including lung cancer. It also summarizes the underlying molecular mechanisms by which ASX protects against pulmonary diseases, including regulating the nuclear factor erythroid 2-related factor/heme oxygenase-1 pathway, NF-κB signaling, mitogen-activated protein kinase signaling, Janus kinase-signal transducers and activators of transcription-3 signaling, the phosphoinositide 3-kinase/Akt pathway, and modulating immune response. Several future directions are proposed in this review. However, most in vitro and in vivo studies have used ASX at concentrations that are not achievable by humans. Also, no clinical trials have been conducted and/or reported. Thus, preclinical studies with ASX treatment within physiological concentrations as well as human studies are required to examine the health benefits of ASX with respect to lung diseases.

ZFPM2-AS1 promotes the proliferation, migration, and invasion of human non-small cell lung cancer cells involving the JAK-STAT and AKT pathways

Purpose

Recent studies have determined that long non-coding RNAs (lncRNAs) are potential prognostic biomarkers for non-small cell lung cancers (NSCLCs). The purpose of this study was to analyze the function and associated pathways of zinc finger protein multitype 2 antisense RNA 1 (ZFPM2-AS1) in NSCLC cells.

Methods

We used qRT-PCR to analyze ZFPM2-AS1’s transcription level. Its proliferation, migration, and invasion capacities were determined using MTT, colony forming, wound healing, and transwell assays. We additionally analyzed the correlation between ZFPM2 and immune infiltration using the Tumor Immune Estimation Resource (TIMER) database, and the protein expression levels using Western blots.

Results

We found that ZFPM2-AS1 expression in NSCLC specimens and cell lines was elevated compared to the control group. ZFPM2-AS1 is an oncogene and independent prognostic predictor of poor survival in NSCLCs, and its expression had a positive correlation with tumor size and lymph node metastasis in our clinical data. MTT, colony forming, wound healing, and transwell assays showed a positive correlation between ZFPM2-AS1 expression and the proliferation, migration, and invasion of NSCLC cells in the presence and absence of interferon- (IFN-γ). Using the TIMER database, we hypothesized that ZFPM2 was negatively correlated with ZFPM2-AS1 expression, as well as the immune infiltration levels in lung adenocarcinoma (LUAD). Finally, we found that ZFPM2-AS1 negatively regulated ZFPM2 expression, and had a positive correlation with PD-L1 expression through the JAK-STAT and AKT pathways.

Conclusion

Our study confirmed that ZFPM2-AS1 promotes the proliferation, migration, and invasion of NSCLC cells via the JAK-STAT and AKT pathways. Further research on the ZFPM2-AS1 pathway regulation mechanism is needed.

Saikosaponin D inhibits proliferation and induces apoptosis of non-small cell lung cancer cells by inhibiting the STAT3 pathway

OBJECTIVE

To study the effects of saikosaponin D (SSD) on proliferation and apoptosis in human non-small cell lung cancer cell lines, and to explore underlying mechanisms.

METHODS

Following treatment with saikosaponin D, A549 and H1299 cells were assessed for anti-proliferation effects using cell cycle kit-8 assays, changes in nuclear morphology using 4',6-diamidino-2-phenylindole (DAPI) staining, and cell apoptosis using annexin V/propidium iodide double staining. Proliferation- and apoptosis-related proteins were detected by immunoblotting.

RESULTS

Saikosaponin D had dose-dependent inhibitory effects on A549 cells (IC₅₀, 3.57 µM) and H1299 cells (IC₅₀, 8.46 µM). DAPI staining revealed decreased cell numbers, and most H1299 cells became round after treatment with 20 µM saikosaponin D. As saikosaponin D concentration increased, the proportions of cells in G0/G1 phase, and cells undergoing apoptosis, increased. Levels of phosphorylated p44/42 and signal transducer and activator of transcription (STAT)3 were significantly downregulated in both cell lines, while total STAT3 levels were not significantly affected. The cleaved form of caspase 3 was significantly upregulated.

CONCLUSIONS

Saikosaponin D inhibits proliferation, inducing cell cycle arrest and apoptosis, in lung cancer cells in a dose-dependent manner, possibly through inhibition of STAT3 phosphorylation and activation of caspase 3.

STAT3 Pathway in Gastric Cancer: Signaling, Therapeutic Targeting and Future Prospects

Molecular signaling pathways play a significant role in the regulation of biological mechanisms, and their abnormal expression can provide the conditions for cancer development. The signal transducer and activator of transcription 3 (STAT3) is a key member of the STAT proteins and its oncogene role in cancer has been shown. STAT3 is able to promote the proliferation and invasion of cancer cells and induces chemoresistance. Different downstream targets of STAT3 have been identified in cancer and it has also been shown that microRNA (miR), long non-coding RNA (lncRNA) and other molecular pathways are able to function as upstream mediators of STAT3 in cancer. In the present review, we focus on the role and regulation of STAT3 in gastric cancer (GC). miRs and lncRNAs are considered as potential upstream mediators of STAT3 and they are able to affect STAT3 expression in exerting their oncogene or onco-suppressor role in GC cells. Anti-tumor compounds suppress the STAT3 signaling pathway to restrict the proliferation and malignant behavior of GC cells. Other molecular pathways, such as sirtuin, stathmin and so on, can act as upstream mediators of STAT3 in GC. Notably, the components of the tumor microenvironment that are capable of targeting STAT3 in GC, such as fibroblasts and macrophages, are discussed in this review. Finally, we demonstrate that STAT3 can target oncogene factors to enhance the proliferation and metastasis of GC cells.

STAT3 is a key molecule in the oncogenic behavior of diffuse intrinsic pontine glioma

Diffuse intrinsic pontine glioma (DIPG) is one of the most lethal childhood brain tumors. This tumor is unique because it is detected exclusively in the ventral pons of patients aged between 6 and 7 years, which suggests a developmental nature of its formation. Signal transducer and activator of transcription 3 (STAT3) is a critical molecule for the differentiation of neural stem cells into astrocytes during neurodevelopment. Additionally, STAT3 is associated with oncogenesis and the epithelial-mesenchymal transition (EMT) in various types of tumor. In recent years, several studies have demonstrated the oncogenic role of STAT3 in high-grade gliomas. However, the role of STAT3 in DIPG at the cellular level remains unknown. To assess the possible association between gliogenesis and DIPG, the expression levels of various molecules participating in the differentiation of neural stem cells were compared between normal brain control tissues and DIPG tissues using open public data. All of the screened genes exhibited significantly increased expression in DIPG tissues compared with normal tissues. As STAT3 expression was the most increased, the effect of STAT3 inhibition in a DIPG cell line was assessed via STAT3 short hairpin (sh)RNA transfection and treatment with AG490, a STAT3 inhibitor. Changes in viability, apoptosis, EMT and radiation therapy efficiency were also evaluated. Downregulation of STAT3 resulted in decreased cyclin D1 expression and cell viability, migration and invasion. Additionally, treatment with STAT3 shRNA or AG490 suppressed the EMT phenotype. Finally, when radiation was administered in combination with STAT3 inhibition, the therapeutic efficiency, assessed by cell viability and DNA damage repair, was increased. The present results suggest that STAT3 is a potential therapeutic target in DIPG, especially when combined with radiation therapy.

STAT3: Versatile Functions in Non-Small Cell Lung Cancer

Signal Transducer and Activator of Transcription 3 (STAT3) activation is frequently found in non-small cell lung cancer (NSCLC) patient samples/cell lines and STAT3 inhibition in NSCLC cell lines markedly impairs their survival. STAT3 also plays a pivotal role in driving tumor-promoting inflammation and evasion of anti-tumor immunity. Consequently, targeting STAT3 either directly or by inhibition of upstream regulators such as Interleukin-6 (IL-6) or Janus kinase 1/2 (JAK1/2) is considered as a promising treatment strategy for the management of NSCLC. In contrast, some studies also report STAT3 being a tumor suppressor in a variety of solid malignancies, including lung cancer. Here, we provide a concise overview of STAT3‘s versatile roles in NSCLC and discuss the yins and yangs of STAT3 targeting therapies.

Sea Hare Hydrolysate-Induced Reduction of Human Non-Small Cell Lung Cancer Cell Growth through Regulation of Macrophage Polarization and Non-Apoptotic Regulated Cell Death Pathways

Sea hare-derived compounds induce macrophage activation and reduce asthmatic parameters in mouse models of allergic asthma. These findings led us to study the role of sea hare hydrolysates (SHH) in cancer pathophysiology. SHH treatment-induced M1 macrophage activation in RAW264.7 cells, peritoneal macrophages, and THP-1 cells, as did lipopolysaccharide (LPS) (+ INF-γ), whereas SHH reduced interleukin (IL)-4 (+IL-13)-induced M2 macrophage polarization. In addition, SHH treatment inhibited the actions of M1 and M2 macrophages, which have anticancer and pro-cancer effects, respectively, in non-small cell lung cancer cells (A549 and HCC-366) and tumor-associated macrophages (TAMs). Furthermore, SHH induced G2/M phase arrest and cell death in A549 cells. SHH also downregulated STAT3 activation in macrophages and A549 cells, and the down-regulation was recovered by colivelin, a STAT3 activator. SHH-induced reduction of M2 polarization and tumor growth was blocked by colivelin treatment. SHH-induced cell death did not occur in the manner of apoptotic signaling pathways, while the death pattern was mediated through pyroptosis/necroptosis, which causes membrane rupture, formation of vacuoles and bleb, activation of caspase-1, and secretion of IL-1β in SHH-treated A549 cells. However, a combination of SHH and colivelin blocked caspase-1 activation. Z-YVAD-FMK and necrostatin-1, pyrotosis and necroptosis inhibitors, attenuated SHH's effect on the cell viability of A549 cells. Taken together, SHH showed anticancer effects through a cytotoxic effect on A549 cells and a regulatory effect on macrophages in A549 cells. In addition, the SHH-induced anticancer effects were mediated by non-apoptotic regulated cell death pathways under STAT3 inhibition. These results suggest that SHH may be offered as a potential remedy for cancer immunotherapy.

The Biomolecular Spectrum Drives Microbial Biology and Functions in Agri-Food-Environments

Microbial biomolecules have huge commercial and industrial potential. In nature, biological interactions are mostly associated with biochemical and biological diversity, especially with the discovery of associated biomolecules from microbes. Within cellular or subcellular systems, biomolecules signify the actual statuses of the microorganisms. Understanding the biological prospecting of the diverse microbial community and their complexities and communications with the environment forms a vital basis for active, innovative biotechnological breakthroughs. Biochemical diversity rather than the specific chemicals that has the utmost biological importance. The identification and quantification of the comprehensive biochemical diversity of the microbial molecules, which generally consequences in a diversity of biological functions, has significant biotechnological potential. Beneficial microbes and their biomolecules of interest can assist as potential constituents for the wide-range of natural product-based preparations and formulations currently being developed on an industrial scale. The understanding of the production methods and functions of these biomolecules will contribute to valorisation of agriculture, food bioprocessing and biopharma, and prevent human diseases related to the environment.

STAT3-mediated Apoptotic-enhancing Function of Sclareol Against Breast Cancer Cells and Cell Sensitization to Cyclophosphamide

Sclareol is an organic compound with potential anti-tumor effects against various cancer types. However, its precise molecular mechanism in the suppression of tumor growth has not been fully elucidated. In the present study, the anti-proliferative and apoptosis-inducing effects of sclareol with cyclophosphamide were investigated in breast cancer cells and the involvement of the JAK/STAT pathway was evaluated. For this purpose, MCF-7 breast cancer cells were cultured and treated with various concentrations of sclareol to determine its IC50. Cell viability was measured by MTT assay and apoptosis was assessed by flow cytometric analysis of annexin V binding. Gene and protein expression were examined by real-time PCR and Western blotting, respectively. The activity of caspase enzymes was also measured. The results showed that sclareol significantly reduced cell viability and triggered cell death and its co-administration with cyclophosphamide enhanced its anti-cancer properties. Additionally, sclareol up-regulated the expression of p53 and BAX and reduced the expression of Bcl-2. Docking studies indicated an interaction between sclareol and STAT3 which was proved by attenuation of STAT3 phosphorylation after treatment of the cells with sclareol. Sclareol was also capable of suppressing the function of IL-6 in modulating the expression of apoptosis-associated genes. Altogether these data suggest the potential of sclareol as an anti-cancer agent and demonstrate that a combination of sclareol with cyclophosphamide might serve as an effective chemotherapeutic approach resulting in improvements in the treatment of breast cancer.

Mechanistic Understanding of Curcumin's Therapeutic Effects in Lung Cancer

Lung cancer is among the most common cancers with a high mortality rate worldwide. Despite the significant advances in diagnostic and therapeutic approaches, lung cancer prognoses and survival rates remain poor due to late diagnosis, drug resistance, and adverse effects. Therefore, new intervention therapies, such as the use of natural compounds with decreased toxicities, have been considered in lung cancer therapy. Curcumin, a natural occurring polyphenol derived from turmeric (Curcuma longa) has been studied extensively in recent years for its therapeutic effects. It has been shown that curcumin demonstrates anti-cancer effects in lung cancer through various mechanisms, including inhibition of cell proliferation, invasion, and metastasis, induction of apoptosis, epigenetic alterations, and regulation of microRNA expression. Several in vitro and in vivo studies have shown that these mechanisms are modulated by multiple molecular targets such as STAT3, EGFR, FOXO3a, TGF-β, eIF2α, COX-2, Bcl-2, PI3KAkt/mTOR, ROS, Fas/FasL, Cdc42, E-cadherin, MMPs, and adiponectin. In addition, limitations, strategies to overcome curcumin bioavailability, and potential side effects as well as clinical trials were also reviewed.

VERU-111 suppresses tumor growth and metastatic phenotypes of cervical cancer cells through the activation of p53 signaling pathway

In this study, we investigated the therapeutic efficacy of VERU-111 in vitro and in vivo model systems of cervical cancer. VERU-111 treatment inhibited cell proliferation and, clonogenic potential, induce accumulation of p53 and down regulated the expression of HPV E6/E7 expression in cervical cancer cells. In addition, VERU-111 treatment also decreased the phosphorylation of Jak2^{(Tyr1007/1008)} and STAT3 at Tyr705 and Ser727. VERU-111 treatment arrested cell cycle in the G2/M phase and modulated cell cycle regulatory proteins (cyclin B1, p21, p34^cdc2 and pcdk1). Moreover, VERU-111 treatment induced apoptosis and modulated the expression of Bid, Bcl-xl, Survivin, Bax, Bcl2 and cleavage in PARP. In functional assays, VERU-111 markedly reduced the migratory and invasive potential of cervical cancer cells via modulations of MMPs. VERU-111 treatment also showed significant (P < 0.05) inhibition of orthotopic xenograft tumor growth in athymic nude mice. Taken together, our results demonstrate the potent anti-cancer efficacy of VERU-111 in experimental cervical cancer models.Thus, VERU-111 can be explored as a promising therapeutic agent for the treatment of cervical cancer.

Vaccinia virus expressing IL-37 promotes antitumor immune responses in hepatocellular carcinoma

The aim of this study was to investigate the effect of vaccinia virus expressing IL-37 (VV-IL-37) on cell proliferation, migration and invasion of hepatocellular carcinoma (HCC) and its possible underlying molecular mechanisms. In this study, we constructed a cancer-targeted vaccinia virus carrying the IL-37 gene knocked in the region of the viral thymidine kinase (TK) gene. Human HCC cell lines were assayed in vitro for cell proliferation, migration and invasion. Serum level, relative mRNA level and protein level of IL-37 in HCC cell lines SMMC7721 and Bel7402 were tested by ELISA assay, qRT-PCR and western blot, respectively. The levels of IL-2, IFN-γ and TNF-α in HCC tumor tissues were also analyzed by ELISA. STAT3 and p-STAT3 expression in tumor tissues were determined by western blot. Our results showed that VV-IL-37 efficiently infected and inhibited HCC cells proliferation, migration and invasion via decreasing STAT3 phosphorylation. In vivo, VV-IL-37 expressed IL-37 at a high level in the transplanted tumor, reduced STAT3 activity, and eventually inhibited tumor growth. In conclusion, we demonstrate that VV-IL-37 promotes antitumor immune responses in HCC.

A novel STAT3 inhibitor, HJC0152, exerts potent antitumor activity in glioblastoma

Aberrant expression and activation of signal transducer and activator of transcription 3 (STAT3) is implicated in several malignancies, including glioblastoma, and is correlated with poor outcomes in patients with glioblastoma, rendering STAT3 a potential therapeutic target. However, few STAT3 inhibitors have been approved for clinical use. We recently developed an orally active small-molecule compound with anti-STAT3 activity, HJC0152. This study aimed to test the effect of this novel drug on glioblastoma cell lines, and provide possibility to improve clinic prognosis of patients with glioblastoma in the future. In the present study, we aimed to determine the effects of HJC0152 on the growth, proliferation, and chemosensitivity of glioblastoma cell lines and xenograft tumors. We found that HJC0152 inactivated STAT3 via inhibiting phosphorylation of the Tyr705 residue. In vitro, HJC0152 suppressed the proliferation and motility of glioblastoma cells, induced apoptosis, and enhanced the chemosensitivity of glioblastoma cells. Furthermore, HJC0152 inhibited the growth of glioblastoma xenograft tumors in vivo. This study provides a rationale for developing HJC0152 as a STAT3-targeting therapy for treating human glioblastoma in the future.

JAK-STAT signalling controls cancer stem cell properties including chemotherapy resistance in myxoid liposarcoma

Myxoid liposarcoma (MLS) shows extensive intratumoural heterogeneity with distinct subpopulations of tumour cells. Despite improved survival of MLS patients, existing therapies have shortcomings as they fail to target all tumour cells. The nature of chemotherapy‐resistant cells in MLS remains unknown. Here, we show that MLS cell lines contained subpopulations of cells that can form spheres, efflux Hoechst dye and resist doxorubicin, all properties attributed to cancer stem cells (CSCs). By single‐cell gene expression, western blot, phospho‐kinase array, immunoprecipitation, immunohistochemistry, flow cytometry and microarray analysis we showed that a subset of MLS cells expressed JAK–STAT genes with active signalling. JAK1/2 inhibition via ruxolitinib decreased, while stimulation with LIF increased, phosphorylation of STAT3 and the number of cells with CSC properties indicating that JAK–STAT signalling controlled the number of cells with CSC features. We also show that phosphorylated STAT3 interacted with the SWI/SNF complex. We conclude that MLS contains JAK–STAT‐regulated subpopulations of cells with CSC features. Combined doxorubicin and ruxolitinib treatment targeted both proliferating cells as well as cells with CSC features, providing new means to circumvent chemotherapy resistance in treatment of MLS patients.

What's new?

Despite improved survival of patients, existing therapies for Myxoid liposarcoma (MLS) present shortcomings as they fail to target all tumour cells. The nature of chemotherapy‐resistant cells in MLS remains unknown, however. Here, the authors show that myxoid liposarcomas are heterogeneous and contain subpopulations of cells with stem cell properties, including chemotherapy resistance. Moreover, JAK‐STAT signalling is active in MLS and regulates the size of the cancer stem cells‐like subpopulation via the SWI/SNF complex. The results shed light on the mechanisms of therapy resistance in MLS and point to JAK‐STAT inhibitors as a new avenue for targeted MLS therapies.

STAT3 Cyclic Decoy Demonstrates Robust Antitumor Effects in Non-Small Cell Lung Cancer

Constitutively activated STAT3 plays a critical role in non-small cell lung carcinoma (NSCLC) progression by mediating proliferation and survival. STAT3 activation in normal cells is transient, making it an attractive target for NSCLC therapy. The therapeutic potential of blocking STAT3 in NSCLC was assessed utilizing a decoy approach by ligating a double-stranded 15-mer oligonucleotide that corresponds to the STAT3 response element of STAT3-target genes, to produce a cyclic STAT3 decoy (CS3D). The decoy was evaluated using NSCLC cells containing either wild-type EGFR (201T) or mutant EGFR with an additional EGFRi resistance mutation (H1975). These cells are resistant to EGFR inhibitors and require an alternate therapeutic approach. CS3D activity was compared with an inactive cyclic control oligonucleotide (CS3M) that differs by a single base pair, rendering it unable to bind to STAT3 protein. Transfection of 0.3 μmol/L of CS3D caused a 50% inhibition in proliferation in 201T and H1975 cells, relative to CS3M, and a 2-fold increase in apoptotic cells. Toxicity was minimal in normal cells. CS3D treatment caused a significant reduction of mRNA and protein expression of the STAT3 target gene c-Myc and inhibited colony formation by 70%. The active decoy decreased the nuclear pool of STAT3 compared with the mutant. In a xenograft model, treatments with CS3D (5 mg/kg) caused a potent 96.5% and 81.7% reduction in tumor growth in 201T (P < 0.007) and H1975 models (P < 0.0001), respectively, and reduced c-Myc and p-STAT3 proteins. Targeting STAT3 with the cyclic decoy could be an effective therapeutic strategy for NSCLC. Mol Cancer Ther; 17(9); 1917-26. ©2018 AACR.

Krukovine Suppresses KRAS-Mutated Lung Cancer Cell Growth and Proliferation by Inhibiting the RAF-ERK Pathway and Inactivating AKT Pathway

Oncogenic activation of the KRAS gene via point mutations occurs in 20-30% of patients with non-small cell lung cancer (NSCLC). The RAS-RAF-ERK and RAS-PI3K-AKT pathways are the major hyper-activated downstream pathways in RAS mutation, which promotes the unlimited lifecycle of cancer cells and their metastasis in humans. However, the success of targeted therapy is restricted by many factors. Herein, we show a new pharmacological KRAS signaling inhibitor krukovine, which is a small molecular bisbenzylisoquinoline alkaloid, isolated from the bark of Abuta grandifolia (Mart.) Sandw. (Menispermaceae). This alkaloid targets the KRAS downstream signaling pathways in different NSCLC cell lines, such as H460 and A549, which are established by KRAS mutations. In the present study, we initially investigated the anti-cancer activities of krukovine in KRAS-mutated NSCLC cell lines, as well as KRAS wild type cancer cell line and normal lung cell. Results indicated that krukovine can inhibit the growth and dose-dependently inhibit the colony formation capacity and wound healing ability of H460 and A549. This cytotoxic effect is associated with the induction of cell apoptosis and G1 arrest in those cell lines. Krukovine treatment also suppressed the C-RAF, ERK, AKT, PI3K, p70s6k, and mTOR phosphorylation in H460 and A549. This finding suggests that krukovine represses the growth and proliferation of KRAS-mutated cells by inactivating AKT signaling pathway and downregulating the RAF-ERK signaling pathway. This study provides detailed insights into the novel cytotoxic mechanism of an anti-cancer compound from an herbal plant and promotes the anti-cancer potential of krukovine in NSCLC with KRAS mutation.

STAT3-siRNA induced B16.F10 melanoma cell death: more association with VEGF downregulation than p-STAT3 knockdown

STAT3 knockdown by small interfering RNA (siRNA) has been described to inhibit carcinogenic growth in various types of tumors. Earlier we have reported delivery of siRNA by oleic acid- and stearic acid-modified-polyethylenimine and enhancement of silencing of STAT3 by small interfering RNA (siRNA) in B16.F10 melanoma cell lines and consequent tumor suppression. Present investigation mainly focused on the downstream events involved in B16.F10 melanoma cell death and consequent tumor suppression following knockdown of p-STAT3 by siRNA. Lipid-substituted polyethylenimine (PEI)-p-STAT3-siRNA were prepared and characterized by measuring its N/P ratio, zeta potential, size, association and dissociation with siRNA. B16.F10 melanoma cells were treated with six different concentrations of PEI-p-STAT3-siRNA (200, 100, 50, 25, 12.5 and 6.25 nM). Downregulation of p-STAT3 and VEGF were studied using western blot and ELISA in association with the melanoma cell death. PEI-p-STAT3-siRNA hydrodynamic diameter ranged from 110 to 270 nm. PEI assisted p-STAT3-siRNA delivery exhibited increased uptake by B16.F10, when analyzed by fluorescent and confocal microscopy along with flowcytometry. It induced concentration-dependent knockdown of the p-STAT3 that also downregulated VEGF expression in similar fashion and induced B16.F10 cell death. Higher concentrations of p-STAT3-siRNA appear to significantly downregulate the VEGF expression via p-STAT3 knockdown. Decreasing survival of B16.F10 cells with the increasing concentration of p-STAT3-siRNA significantly correlated with VEGF downregulation, not with p-STAT3 expression. Data suggest that VEGF downregulation following knockdown of p-STAT3 may be a key event in survival reduction in B16.F10 melanoma cells and.