Search for novel STAT3-dependent genes reveals SERPINA3 as a new STAT3 target that regulates invasion of human melanoma cells

Enhancement of radio-sensitivity by inhibition of Janus kinase signaling with oclacitinib in canine tumor cell lines

A combination of irradiation and oclacitinib, a Janus kinase (JAK) inhibitor used in dogs, could lead to synergistic anticancer effects in canine tumors. However, the anti-tumor effects of oclacitinib remain unclear. This study investigated the radio-sensitizing effect of oclacitinib in canine tumors and determined its underlying mechanisms using osteosarcoma (HMPOS), malignant melanoma (CMeC), and thyroid adenocarcinoma (CTAC) cell lines. A clonogenic assay and a tumor growth assessment in a xenograft mouse model (BALB/cAJcl-nu/nu) were performed to evaluate the radio-sensitizing effects of oclacitinib. Oclacitinib enhanced the radio-sensitivity of tumor cells both in vitro and in vivo. The signal transducer and activator of transcription (STAT)3 expression was activated and suppressed by oclacitinib in X-irradiation-exposed cells. Oclacitinib enhanced radiation-induced apoptosis only in HMPOS cells by inhibiting anti-apoptotic genes. In addition, oclacitinib inhibited the transcription of cell-cycle-regulating genes and arrested cell cycle progression from the G1 phase to subsequent phases. In conclusion, oclacitinib enhanced radio-sensitivity both in vitro and in vivo by triggering apoptosis and impeding cell cycle progression via STAT3 inhibition in canine tumor cell lines. This study suggested the clinical therapeutic potential of oclacitinib and radiation therapy in enhancing treatment efficacy and outcomes in canine tumors.

Crosstalk Between nNOS/NO and COX-2 Enhances Interferon-Gamma-Stimulated Melanoma Progression

Background/Objectives: Interferon gamma (IFN-γ) in the melanoma tumor microenvironment plays opposing roles, orchestrating both pro-tumorigenic activity and anticancer immune responses. Our previous studies demonstrated the role of neuronal nitric oxide synthase (nNOS) in IFN-γ-stimulated melanoma progression. However, the underlying mechanism has not been well defined. This study determined whether the nNOS/NO and COX-2/PGE2 signaling pathways crosstalk and augment the pro-tumorigenic effects of IFN-γ in melanoma. Methods: Bioinformatic analysis of patient and cellular proteomic data was conducted to identify proteins of interest associated with IFN-γ treatment in melanoma. Changes in protein expression were determined using various analytical techniques including western blot, flow cytometry, and confocal microscopy. The levels of PGE2 and nitric oxide (NO) were analyzed by HPLC chromatography and flow cytometry. In vivo antitumor efficacy was determined utilizing a human melanoma xenograft mouse model. Results: Our omics analyses revealed that the induction of COX-2 was significantly predictive of IFN-γ treatment in melanoma cells. In the presence of IFN-γ, PGE2 further enhanced PD-L1 expression and amplified the induction of nNOS, which increased intracellular NO levels. Cotreatment with celecoxib effectively diminished these changes induced by PGE2. In addition, nNOS blockade using a selective small molecule inhibitor (HH044), efficiently inhibited IFN-γ-induced PGE2 and COX-2 expression levels in melanoma cells. STAT3 inhibitor napabucasin also inhibited COX-2 expression both in the presence and absence of IFN-γ. Furthermore, celecoxib was shown to enhance HH044 cytotoxicity in vitro and effectively inhibit human melanoma tumor growth in vivo. HH044 treatment also significantly reduced tumor PGE2 levels in vivo. Conclusions: Our study demonstrates the positive feedback loop linking nNOS-mediated NO signaling to the COX-2/PGE2 signaling axis in melanoma, which further potentiates the pro-tumorigenic activity of IFN-γ.

PARD6A promotes lung adenocarcinoma cell proliferation and invasion through Serpina3

Par6α encoded by PARD6A is a member of the PAR6 family and is reported to promote cancer initiation and progression. PARD6A is frequently upregulated in different types of cancers, but its regulatory role in lung cancer progression is yet to be established. In this study, we analyzed the PARD6A expression in biopsies from lung adenocarcinoma (LUAD) patients, and the survival probability using LUAD tissue microarray (TMA) and online datasets from TCGA and GEO. We conducted in vitro and in vivo assays to assess the role of PARD6A in regulating lung cancer progression, including proliferation, wound healing, transwell, RNA-seq, and subcutaneous tumor mice models. Our findings revealed that PARD6A is highly expressed in cancer tissues from LUAD patients and is associated with poor prognosis in LUAD patients. In vitro assays showed that PARD6A promoted cell proliferation, migration, and invasion. The transcriptome sequencing identified Serpina3 as one of the key downstream molecules of PARD6A. Ectopic expression of Serpina3 rescued impaired proliferation, migration, and invasion in PARD6A-knocking down H1299 cells, whereas silencing Serpina3 impeded enhanced proliferation, migration, and invasion in PARD6A-overexpressing H1975 cells. Our findings suggest that PARD6A promotes lung cancer progression by inducing Serpina3, which may be a promising therapeutic target.

SERPINA3 is a marker of cartilage differentiation and is essential for the expression of extracellular matrix genes during early chondrogenesis

Serine proteinase inhibitors (serpins) are a family of structurally similar proteins which regulate many diverse biological processes from blood coagulation to extracellular matrix (ECM) remodelling. Chondrogenesis involves the condensation and differentiation of mesenchymal stem cells (MSCs) into chondrocytes which occurs during early development. Here, and for the first time, we demonstrate that one serpin, SERPINA3 (gene name SERPINA3, protein also known as alpha-1 antichymotrypsin), plays a critical role in chondrogenic differentiation. We observed that SERPINA3 expression was markedly induced at early time points during in vitro chondrogenesis. We examined the expression of SERPINA3 in human cartilage development, identifying significant enrichment of SERPINA3 in developing cartilage compared to total limb, which correlated with well-described markers of cartilage differentiation. When SERPINA3 was silenced using siRNA, cartilage pellets were smaller and contained lower proteoglycan as determined by dimethyl methylene blue assay (DMMB) and safranin-O staining. Consistent with this, RNA sequencing revealed significant downregulation of genes associated with cartilage ECM formation perturbing chondrogenesis. Conversely, SERPINA3 silencing had a negligible effect on the gene expression profile during osteogenesis suggesting the role of SERPINA3 is specific to chondrocyte differentiation. The global effect on cartilage formation led us to investigate the effect of SERPINA3 silencing on the master transcriptional regulator of chondrogenesis, SOX9. Indeed, we observed that SOX9 protein levels were markedly reduced at early time points suggesting a role for SERPINA3 in regulating SOX9 expression and activity. In summary, our data support a non-redundant role for SERPINA3 in enabling chondrogenesis via regulation of SOX9 levels.

CTSC promoted the migration and invasion of glioma cells via activation of STAT3/SERPINA3 axis

Cathepsin C (CTSC) has been reported to be upregulated in several cancers, however, there are still many missing links about the role of CTSC in glioma. To address this knowledge gap, the present study employed bioinformatics analysis, Transwell assay, RT-qPCR and Western blot assays to investigate the expression level of CTSC in glioma tissues, its relationship with survival period, and its effect on the migration and invasion ability of glioma cells. The findings revealed that CTSC was upregulated in glioma and was associated with poor prognosis. Moreover, CTSC was found to promote cell migration and invasion abilities as well as epithelial-mesenchymal transition (EMT). A further study found that CTSC induced SERPINA3 and STAT3 expression in glioma cells. Additionally, we demonstrated that STAT3 signaling mediated upregulation of SERPINA3 expression by CTSC. In sum, our findings suggest that CTSC activates the STAT3/SERPINA3 axis to promote migration and invasion of glioma cells, which may lead to new potential therapeutic approaches for humans with cancer.

Current evidence regarding the cellular mechanisms associated with cancer progression due to cardiovascular diseases

Several large cohort studies in cardiovascular disease (CVD) patients have shown an increased incidence of cancer. Previous studies in a myocardial infarction (MI) mouse model reported increased colon, breast, and lung cancer growth. The potential mechanisms could be due to secreted cardiokines and micro-RNAs from pathological hearts and immune cell reprogramming. A study in a MI-induced heart failure (HF) mouse demonstrated an increase in cardiac expression of SerpinA3, resulting in an enhanced proliferation of colon cancer cells. In MI-induced HF mice with lung cancer, the attenuation of tumor sensitivity to ferroptosis via the secretion of miR-22-3p from cardiomyocytes was demonstrated. In MI mice with breast cancer, immune cell reprogramming toward the immunosuppressive state was shown. However, a study in mice with renal cancer reported no impact of MI on tumor growth. In addition to MI, cardiac hypertrophy was shown to promote the growth of breast and lung cancer. The cardiokine potentially involved, periostin, was increased in the cardiac tissue and serum of a cardiac hypertrophy model, and was reported to increase breast cancer cell proliferation. Since the concept that CVD could influence the initiation and progression of several types of cancer is quite new and challenging regarding future therapeutic and preventive strategies, further studies are needed to elucidate the potential underlying mechanisms which will enable more effective risk stratification and development of potential therapeutic interventions to prevent cancer in CVD patients.

Immunohistochemical Expression of the SERPINA3 Protein in Uterine Fibroids

BACKGROUND

SERPINA3 (α-1-antichymotrypsin, AACT, ACT) is produced by the liver and released into plasma in an anti-inflammatory response and plays a role as a modulator of extracellular matrix (ECM) by inhibiting serine proteases. Numerous studies proved an increased level of SERPINA3 in many types of cancer, which could be linked to SERPINA3's anti-apoptotic function.

AIM

In the context of progressive ECM fibrosis during the development of uterine fibroids, which are one of the most common hypertrophic changes within the uterus, it is interesting to describe the level of SERPINA3 protein in this type of lesion and the surrounding tissues.

METHODS

We used immunohistochemical staining of the SERPINA3 protein and compared the intensity of the signal between the myoma tissue and the surrounding normal tissue.

RESULTS

We showed a surprising reduction in the amount of the SERPINA3 protein within uterine fibroids compared to surrounding tissues.

CONCLUSION

This observation sheds new light on the role of this protein in the formation of proliferative changes and suggests that understanding the mechanism of its action may become the basis for the development of new diagnostic and therapeutic tools.

Inflammatory signaling pathways in the treatment of Alzheimer's disease with inhibitors, natural products and metabolites (Review)

The intricate nature of Alzheimer's disease (AD) pathogenesis poses a persistent obstacle to drug development. In recent times, neuroinflammation has emerged as a crucial pathogenic mechanism of AD, and the targeting of inflammation has become a viable approach for the prevention and management of AD. The present study conducted a comprehensive review of the literature between October 2012 and October 2022, identifying a total of 96 references, encompassing 91 distinct pharmaceuticals that have been investigated for their potential impact on AD by inhibiting neuroinflammation. Research has shown that pharmaceuticals have the potential to ameliorate AD by reducing neuroinflammation mainly through regulating inflammatory signaling pathways such as NF‑κB, MAPK, NLRP3, PPARs, STAT3, CREB, PI3K/Akt, Nrf2 and their respective signaling pathways. Among them, tanshinone IIA has been extensively studied for its anti‑inflammatory effects, which have shown significant pharmacological properties and can be applied clinically. Thus, it may hold promise as an effective drug for the treatment of AD. The present review elucidated the inflammatory signaling pathways of pharmaceuticals that have been investigated for their therapeutic efficacy in AD and elucidates their underlying mechanisms. This underscores the auspicious potential of pharmaceuticals in ameliorating AD by impeding neuroinflammation.

The versatile role of Serpina3c in physiological and pathological processes: a review of recent studies

Murine Serpina3c belongs to the family of serine protease inhibitors (Serpins), clade "A" and its human homologue is SerpinA3. Serpina3c is involved in some physiological processes, including insulin secretion and adipogenesis. In the pathophysiological process, the deletion of Serpina3c leads to more severe metabolic disorders, such as aggravated non-alcoholic fatty liver disease (NAFLD), insulin resistance and obesity. In addition, Serpina3c can improve atherosclerosis and regulate cardiac remodeling after myocardial infarction. Many of these processes are directly or indirectly mediated by its inhibition of serine protease activity. Although its function has not been fully revealed, recent studies have shown its potential research value. Here, we aimed to summarize recent studies to provide a clearer view of the biological roles and the underlying mechanisms of Serpina3c.

Sinapic acid and 3,3′-diindolylmethane potentiate cyclophosphamide antitumor activity through induction of apoptosis and inhibition of metastasis

AIM

New therapeutic strategies are required to enhance the anticancer efficacy of chemotherapeutic drugs and to reduce their cytotoxicity. The purpose of this study was to assess the anti-tumor, antimetastatic and anti-apoptotic activities of sinapic acid (SA) and 3,3'-diindolylmethane (DIM) in solid Ehrlich carcinoma (SEC) induced in mice and combining SA or DIM compounds with cyclophosphamide (CYP).

METHODS

For induction of solid tumor, the right hind limbs of mice were inoculated subcutaneously with Ehrlich carcinoma cells. After 5 days of tumor inoculation, mice were treated with SA (56 mg/kg), DIM (40 mg/kg), CYP (10 mg/kg), and their combinations (SA/CYP) and (SA/DIM) for 21 days. The mRNA levels of Elabela, Serpina3, caspase-3, MMP-2 and MMP-9 were assessed by qPCR. Tumor and liver tissues were stained with hematoxylin and eosin for histological examination. Serum was investigated for ALT and AST activities.

MAIN FINDINGS

Treatment of SEC mice with SA and DIM significantly reduced solid tumor weight by 45.6% and 33.2%, respectively. They also reduced tumor size and increased life span of SEC mice. SA and DIM diminished area of metastatic nodules of tumor cells in the liver by 54.1% and 47.4%, respectively. They also reduced serum aminotransferases activities. Both SA and DIM were found to upregulate caspase 3 and downregulate MMP-2 and MMP-9. Furthermore, SA and DIM reduced gene expression of Elabela by (44.8% and 35.1%) and Serpina3 by (30.7% and 23.5%), respectively. SA and DIM were also shown to potentiate the anti-tumor activity CYP. SA and DIM showed promising antitumor effects and enhanced CYP antitumor activity mostly through upregulation of apoptotic caspase 3 and suppressing metastatic enzymes MMP-2 and MMP-9. Additionally, SA and DIM exhibited a hepatoprotective effect. Our results suggest that these natural compounds may be used to improve the efficacy and reduce the adverse effects of chemotherapeutic drugs in the treatment of solid malignancies.

Nanodelivery systems for cutaneous melanoma treatment

Cutaneous melanoma (CM) is a multifactorial disease whose treatment still presents challenges: the rapid progression to advanced CM, which leads to frequent recurrences even after surgical excision and, notably, the low response rates and resistance to the available therapies, particularly in the case of unresectable metastatic CM. Thereby, alternative innovative therapeutic approaches for CM continue to be searched. In this review we discuss relevant preclinical research studies, and provide a broad-brush analysis of patents and clinical trials which involve the application of nanotechnology-based delivery systems in CM therapy. Nanodelivery systems have been developed for the delivery of anticancer biomolecules to CM, which can be administered by different routes. Overall, nanosystems could promote technological advances in several therapeutic modalities and can be used in combinatorial therapies. Nevertheless, the results of these preclinical studies have not been translated to clinical applications. Thus, concerted and collaborative research studies involving basic, applied, translational, and clinical scientists need to be performed to allow the development of effective and safe nanomedicines to treat CM.

SERPINA3: Stimulator or Inhibitor of Pathological Changes

SERPINA3, also called α-1-antichymotrypsin (AACT, ACT), is one of the inhibitors of serine proteases, one of which is cathepsin G. As an acute-phase protein secreted into the plasma by liver cells, it plays an important role in the anti-inflammatory response and antiviral response. Elevated levels of SERPINA3 have been observed in heart failure and neurological diseases such as Alzheimer's disease or Creutzfeldt-Jakob disease. Many studies have shown increased expression levels of the SERPINA3 gene in various types of cancer, such as glioblastoma, colorectal cancer, endometrial cancer, breast cancer, or melanoma. In this case, the SERPINA3 protein is associated with an antiapoptotic function implemented by adjusting the PI3K/AKT or MAPK/ERK 1/2 signal pathways. However, the functions of the SERPINA3 protein are still only partially understood, mainly in the context of cancerogenesis, so it seems necessary to summarize the available information and describe its mechanism of action. In particular, we sought to amass the existing body of research focusing on the description of the underlying mechanisms of various diseases not related to cancer. Our goal was to present an overview of the correct function of SERPINA3 as part of the defense system, which unfortunately easily becomes the "Fifth Column" and begins to support processes of destruction.

Reactive astrocytes transduce inflammation in a blood-brain barrier model through a TNF-STAT3 signaling axis and secretion of alpha 1-antichymotrypsin

Astrocytes are critical components of the neurovascular unit that support blood-brain barrier (BBB) function. Pathological transformation of astrocytes to reactive states can be protective or harmful to BBB function. Here, using a human induced pluripotent stem cell (iPSC)-derived BBB co-culture model, we show that tumor necrosis factor (TNF) transitions astrocytes to an inflammatory reactive state that causes BBB dysfunction through activation of STAT3 and increased expression of SERPINA3, which encodes alpha 1-antichymotrypsin (α1ACT). To contextualize these findings, we correlated astrocytic STAT3 activation to vascular inflammation in postmortem human tissue. Further, in murine brain organotypic cultures, astrocyte-specific silencing of Serpina3n reduced vascular inflammation after TNF challenge. Last, treatment with recombinant Serpina3n in both ex vivo explant cultures and in vivo was sufficient to induce BBB dysfunction-related molecular changes. Overall, our results define the TNF-STAT3-α1ACT signaling axis as a driver of an inflammatory reactive astrocyte signature that contributes to BBB dysfunction.

Unfolding the cascade of SERPINA3: Inflammation to cancer

SERine Protease INhibitor clade A member 3 (SERPINA3), a member of the SERine-Protease INhibitor (SERPIN) superfamily, principally works as a protease inhibitor in maintaining cellular homeostasis. It is a matricellular acute-phase glycoprotein that appears to be the sole nuclear-binding secretory serpin. Several studies have emerged in recent years demonstrating its link to cancer and disease biology. SERPINA3 seems to have cancer- and compartment-specific biological functions, acting either as a tumour promoter or suppressor in different cancers. However, the localization, mechanism of action and the effectors of SERPINA3 in physiological and pathological scenarios remain obscure. Our review aims to consolidate the current evidence of SERPINA3 in various cancers, highlighting its association with the cancer hallmarks and ratifying its status as an emerging cancer biomarker. The elucidation of SERPINA3-mediated cancer progression and its targeting might shed light on the realm of cancer therapeutics.

HOXA-AS2 enhances GBM cell malignancy by suppressing miR-2116-3p thereby upregulating SERPINA3

Background

Glioblastoma (GBM) is malignant, demanding more attention to the improvement of the diagnosis and therapy. LncRNAs have been implicated in the malignancy of GBM cells.

Methods

HOXA-AS2, miR-2116-3p and SERPINA3 expression levels in GBM tissues and cell lines were detected by qRT-PCR. Western blotting was performed to detect the protein levels of Bax and Bcl-2. Dual-luciferase reporter assay was for detection of relationship among these factors, together with RIP and RNA pull-down. CCK-8, EdU, wound healing and transwell assays were for detection of the role of HOXA-AS2, miR-2116-3p and SERPINA3 in cell viability, proliferation, migration and invasion in GBM, respectively.

Results

HOXA-AS2 and SERPINA3 showed higher level in GBM tissues and cell lines. Low level of HOXA-AS2 attenuated GBM cell growth in vitro. Moreover, the anti-tumor impact of silenced HOXA-AS2 was restored by miR-2116-3p inhibitor, but its tumor-promotional effect could be reversed by silenced SERPINA3.

Conclusion

HOXA-AS2 enhanced GBM cell malignancy through sponging miR-2116-3p and releasing SERPINA3, which might shed light on the diagnosis and therapy for GBM in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09462-y.

Highly expressed of SERPINA3 indicated poor prognosis and involved in immune suppression in glioma

Introduction

The prognosis of patients with glioma is dismal. It has been reported that Serpin peptidase inhibitor clade A member 3 (SERPINA3) is associated with the mobility and invasion of tumor cells. Our study was designed to explore the value of SERPINA3 messenger RNA (mRNA) expression in the biological process, prognosis, and immune significance in glioma.

Methods

We analyzed the biological functions of SERPINA3 through data from the Chinese Glioma Genome Atlas databases. Differentially expressed genes and enrichment analysis were performed and correlations between SERPINA3 expression and immune cell infiltration were analyzed. Further, we validated the expression and the survival prediction role of SERPINA3 by using tissue microarrays and RNAscope in situ hybridization in 321 gliomas. The correlations between the expression and clinical‐pathological parameters as well as other biomarkers were examined.

Results

Univariate and multivariate regression both indicated that the level of SERPINA3 transcript represented an independent prognostic factor. High levels of SERPINA3 correlated with poor survival in patients with glioma. Expression of SERPINA3 mRNA was observed positively correlated with MCM6, IGFBP2, and FKBP10. Enrichment analysis showed SERPINA3 mainly enriched in immune‐related terms and signaling pathways including MAPK, TNF, P53, PI3K‐Akt, nuclear factor‐κB. Immune infiltration analysis further declare the SERPINA3 expression negatively correlated with levels of Macrophages M1, native CD4⁺ T cell, monocytes, and Mast cell activated. And overexpression of SERPINA3 correlated with low CD4⁺ T cell infiltration in glioma tissues.

Conclusions

SERPINA3 may play a key role in the biological process of glioma cells especially in immune suppression activities. SERPINA3 may serve as an independent survival prediction factor in glioma patients.

The role of Hypoxia-Inducible Factor-1alpha and its signaling in melanoma

Adaptation to the loss of O2 is regulated via the activity of hypoxia-inducible factors such as Hypoxia-Inducible Factor-1 (HIF-1). HIF-1 acts as a main transcriptional mediator in the tissue hypoxia response that regulates over 1000 genes related to low oxygen tension. The role of HIF-1α in oncogenic processes includes angiogenesis, tumor metabolism, cell proliferation, and metastasis, which has been examined in various malignancies, such as melanoma. Melanoma is accompanied by a high death rate and a cancer type whose incidence has risen over the last decades. The linkage between O2 loss and melanogenesis had extensively studied over decades. Recent studies revealed that HIF-1α contributes to melanoma progression via different signaling pathways such as PI3K/Akt/mTOR, RAS/RAF/MEK/ERK, JAK/STAT, Wnt/β-catenin, Notch, and NF-κB. Also, various microRNAs (miRs) are known to mediate the HIF-1α role in melanoma. Therefore, HIF-1α offers a diagnostic/prognostic biomarker and a candidate for targeted therapy in melanoma.

Differential gene expression in peritumoral brain zone of glioblastoma: role of SERPINA3 in promoting invasion, stemness and radioresistance of glioma cells and association with poor patient prognosis and recurrence

PURPOSE

Glioblastoma (GBM) is a highly invasive tumor. Despite advances in treatment modalities, tumor recurrence is common, seen mainly in the peritumoral brain zone (PBZ). We aimed to molecularly characterize PBZ, to understand the pathobiology of tumor recurrence.

METHODS/PATIENTS

We selected eight differentially regulated genes from our previous transcriptome profiling study on tumor core and PBZ. Expression of selected genes were validated in GBM (tumor core and PBZ, n = 37) and control (n = 22) samples by real time quantitative polymerase chain reaction (qPCR). Serine protease inhibitor clade A, member 3 (SERPINA3) was selected for further functional characterization in vitro by gene knockdown approach in glioma cells. Its protein expression by immunohistochemistry (IHC) was correlated with other clinically relevant GBM markers, patient prognosis and tumor recurrence.

RESULTS

The mRNA expression of selected genes from the microarray data validated in tumor core and PBZ and was similar to publicly available databases. SERPINA3 knock down in vitro showed decreased tumor cell proliferation, invasion, migration, transition to mesenchymal phenotype, stemness and radioresistance. SERPINA3 protein expression was higher in PBZ compared to tumor core and also was higher in older patients, IDH wild type and recurrent tumors. Finally, its expression showed positive correlation with poor patient prognosis.

CONCLUSIONS

SERPINA3 expression contributes to aggressive GBM phenotype by regulating pro-tumorigenic actions in vitro and is associated with adverse clinical outcome.

Application of decoy oligodeoxynucleotides strategy for inhibition of cell growth and reduction of metastatic properties in nonresistant and erlotinib-resistant SW480 cell line

Signal transducer and activator of transcription 3 (STAT3) is a critical regulator for angiogenesis, cell cycle progression, apoptosis, and drug resistance. Resistance toward EGF receptor (EGFR) inhibitors is a significant clinical concern for metastatic colon cancer patients. The present study aimed to evaluate the blocking influences of STAT3 decoy oligodeoxynucleotides (ODNs) on the STAT3 survival signaling pathway in nonresistant and erlotinib-resistant SW480 colon cancer cells. First, STAT3 decoy and scramble ODNs were designed according to STAT3 elements in the promoter region of MYCT1 gene and tested for the interaction of STAT3 protein with designed ODNs via in silico molecular docking study. Then, the efficiency of transfection and subcellular localization of ODNs were assessed using flow cytometry and fluorescence microscopy, respectively. Cell viability, cell cycle, and apoptosis tests, scratch and colony formation assays, and real-time PCR were also used to study the cancerous properties of cells. A considerable decrease in proliferation of colon cancer cells was observed with blockade of STAT3 signaling due to cell cycle arrest and induced apoptosis via downregulation of cyclin D1 and Bcl-XL, respectively. Furthermore, upon transfecting STAT3 decoy ODNs, colony formation potential and migration activity in both SW480 colon cancer cell lines were decreased compared to the control groups. From this study, it could be concluded that STAT3 is critical for cell growth inhibition and metastatic properties reduction of resistant SW480 colon cancer cells; therefore, STAT3 decoy ODNs could be considered as potential therapeutics along with current remedies for treating drug-resistant colon cancer.

Evaluation of STAT3 decoy oligodeoxynucleotides' synergistic effects on radiation and/or chemotherapy in metastatic breast cancer cell line

Resistance to radiotherapy and chemotherapy has been a major problem of conventional cancer therapies, which consequently leads to cancer relapse and cancer-related death. It is known that cancer stem cells (CSCs) play a key role in therapy resistance and CSC-based targeted therapies have been considered as a powerful tool for cancer treatment. In the current study, we investigated the synergistic effects of suppressing signal transducer and activator of transcription (STAT3) function by decoy ODNs on X-irradiation (XI) and methotrexate (MTX) exposure as a combinational therapy in triple-negative breast cancer (TNBC) MDA-MB-231 cells. Lipofectamine 2000® was used as a transfecting agent and the cells treated with Scramble ODNs (SCR) and decoy ODNs were subjected to irradiation with 2 Gy at single/fractionated (XI group) doses, different concentration of MTX group, and X-irradiation-methotrexate (XI/MTX group). Synergistic effects of STAT3 SCR and decoy ODNs on cells were investigated by cell viability (MTT), cell cycle profile, apoptosis rate, migration, and invasion assays. Statistical analysis of obtained data showed that STAT3 decoy ODNs significantly decreased the cell viability, arrested the growth at G0/G1 phase, increased apoptosis rate, and reduced migrated and invaded cells through transwell membrane, in XI, MTX, and XI/MTX exposed groups. Since STAT3 is a master transcription factor in breast cancer cells stemness, aggressiveness, TNBC's heterogeneity, and therapy resistance; therefore, inhibition of this transcription factor by decoy ODNs could increase antitumor efficiencies of XI and MTX exposure strategies. Accordingly, this method could have the potential to increase the efficiency of combination therapies.

TAK-242 ameliorates DSS-induced colitis by regulating the gut microbiota and the JAK2/STAT3 signaling pathway

BACKGROUND

The goal of the present study was to investigate the effects of TAK-242 on the gut microbiota and the TLR4/JAK2/STAT3 signaling pathway in mice with dextran sulfate sodium (DSS)-induced colitis.

RESULTS

At the phylum level, Bacteroidetes, Firmicutes, Actinobacteria, Cyanobacteria, Epsilonbacteraeota and Proteobacteria were the primary microbiota in the five groups. TAK-242 treatment significantly enhanced Verrucomicrobia and Actinobacteria; significantly decreased Cyanobacteria, Epsilonbacteraeota and Proteobacteria; and particularly promoted the growth of Akkermansia. TAK-242 markedly alleviated DSS-induced colitis symptoms and colonic lesions by promoting IL-10 release, inhibiting IL-17 release, downregulating TLR4 and JAK2/STAT3 mRNA and protein expression and increasing JAK2/STAT3 phosphorylation.

CONCLUSION

TAK-242 modulates the structure of the gut microbiota in colitis and may be a novel therapeutic candidate for ulcerative colitis.

Suppressing the metastatic properties of the breast cancer cells using STAT3 decoy oligodeoxynucleotides: A promising approach for eradication of cancer cells by differentiation therapy

Due to the presence of cancer stem cells (CSCs), breast cancer often relapsed after conventional therapies. Strategies that induce differentiation of CSCs will be helpful in eradication of tumor cells, so we designed an oligodeoxynucleotide (ODNs) for targeting of signal transducer and activator of transcription 3 (STAT3) transcription factor which is involved in stemness, and constitutively activated in triple-negative breast cancer. Molecular docking and electrophoretic mobility shift assay analysis showed that decoy ODN bound specifically to the DNA binding site of STAT3 protein. The prevalent uptake of Cy3-labeled ODNs is in the cytoplasm and the nucleus of MDA-MB-231 treated cells. STAT3 decoy ODNs treatment showed cell growth inhibition by decreasing cell viability (17%), increasing the percentage of arrested cells in G0/G1 phases (18%), and triggering apoptosis (29%). Migration and invasion potential decreased from 10.77 to 6.76 µm/hr, by wound closure rate, and migrated/invaded percentage by 26.4% and 15.4% in the transwell assays, respectively. CD44 protein expression level on the cell surface also decreased, while CD24 increased. Mammosphere formation efficiency reduced in terms of tumorsphere size by 47%, while the required time increased. Cells morphology was changed, and lipid droplets were accumulated in the cytoplasm compared to the control and scrambled groups, in all assays (repeated triplicate). Furthermore, the gene expression of all downstream targets significantly decreased owing to suppressing the STAT3 transcription factor. Overall, the results confirmed the antitumor effects of STAT3 decoy in MDA-MB-231 cells. Thus, it seems that STAT3 decoy ODNs might be considered as an auxiliary tool for breast cancer eradicating by the differentiation therapy approach.

A worm gel-based 3D model to elucidate the paracrine interaction between multiple myeloma and mesenchymal stem cells

Multiple myeloma (MM) is a malignancy of terminally-differentiated plasma cells that develops mainly inside the bone marrow (BM) microenvironment. It is well known that autocrine and paracrine signals are responsible for the progression of this disease but the precise mechanism and contributions from single cell remain largely unknown. Mesenchymal stem cells (MSC) are an important cellular component of the BM: they support MM growth by increasing its survival and chemo-resistance, but little is known about the paracrine signaling pathways. Three-dimensional (3D) models of MM-MSC paracrine interactions are much more biologically-relevant than simple 2D models and are considered essential for detailed studies of MM pathogenesis. Herein we present a novel 3D co-culture model designed to mimic the paracrine interaction between MSC and MM cells. MSC were embedded within a previously characterized thermoresponsive block copolymer worm gel that can induce stasis in human pluripotent stem cells (hPSC) and then co-cultured with MM cells. Transcriptional phenotyping of co-cultured cells indicated the dysregulation of genes that code for known disease-relevant factors, and also revealed IL-6 and IL-10 as upstream regulators. Importantly, we have identified a synergistic paracrine signaling pathway between IL-6 and IL-10 that plays a critical role in sustaining MM cell proliferation. Our findings indicate that this 3D co-culture system is a useful model to investigate the paracrine interaction between MM cells and the BM microenvironment in vitro. This approach has revealed a new mechanism that promotes the proliferation of MM cells and suggested a new therapeutic target.

The JAK2/STAT3 pathway is involved in the anti-melanoma effects of brevilin A

AIMS

Melanoma is lethal. Constitutively active signal transducer and activator of transcription 3 (STAT3) has been proposed as a pathogenic factor and a therapeutic target of melanoma. Brevilin A, a sesquiterpene lactone isolated from Centipeda minima (L.) A. Br. et Aschers., has been shown to exert antineoplastic effects and inhibit the STAT3 pathway in nasopharyngeal, lung, prostate and breast cancer cells. This study aimed to determine whether brevilin A has anti-melanoma effects, and whether STAT3 signaling is involved in the effects.

MAIN METHODS

A mouse A375 xenograft model, as well as A375 and A2058 cell models were employed to assess the in vivo and in vitro anti-melanoma effects of brevilin A. A375 cells stably expressing STAT3C, a constitutively active STAT3 mutant, were used to determine the role of STAT3 signaling in brevilin A's anti-melanoma effects.

KEY FINDINGS

Intraperitoneal injection of brevilin A dose-dependently inhibited melanoma growth in mice and suppressed STAT3 phosphorylation in the tumors. In cultured cells, brevilin A reduced cell viability, induced apoptosis, suppressed migration and invasion, decreased protein levels of phospho-JAK2 (Y1007/1008) and phospho-STAT3 (Tyr705), and restrained STAT3 nuclear localization. STAT3 over-activation diminished brevilin A's effects on cell viability and migration. Collectively, brevilin A exerts anti-melanoma effects and these effects are at least in part attributed to the inhibition of the JAK2/STAT3 pathway.

SIGNIFICANCE

Our findings provide a pharmacological basis for developing brevilin A as a new phytotherapeutic agent against melanoma.