The JAK2 inhibitor AZD1480 potently blocks Stat3 signaling and oncogenesis in solid tumors

Targeting oncogenic kinases: Insights on FDA approved tyrosine kinase inhibitors

Protein kinases play pivotal roles in various biological functions, influencing cell differentiation, promoting survival, and regulating the cell cycle. The disruption of protein kinase activity is intricately linked to pathways in tumor development. This manuscript explores the transformative impact of protein kinase inhibitors on cancer therapy, particularly their efficacy in cases driven by targeted mutations. Focusing on key tyrosine kinase inhibitors (TKIs) like Bcr-Abl, Epidermal Growth Factor Receptor (EGFR), and Vascular Endothelial Growth Factor Receptor (VEGFR), it targets critical kinase families in cancer progression. Clinical trial details of these TKIs offer insights into their therapeutic potentials. Learning from FDA-approved kinase inhibitors, the review dissects trends in kinase drug development since imatinib's paradigm-shifting approval in 2001. TKIs have evolved into pivotal drugs, extending beyond oncology. Ongoing clinical trials explore novel kinase targets, revealing the vast potential within the human kinome. The manuscript provides a detailed analysis of advancements until 2022, discussing the roles of specific oncogenic protein kinases in cancer development and carcinogenesis. Our exploration on PubMed for relevant and significant TKIs undergoing pre-FDA approval phase III clinical trials enriches the discussion with valuable findings. While kinase inhibitors exhibit lower toxicity than traditional chemotherapy in cancer treatment, challenges like resistance and side effects emphasize the necessity of understanding resistance mechanisms, prompting the development of novel inhibitors like osimertinib targeting specific mutant proteins. The review advocates thorough research on effective combination therapies, highlighting the future development of more selective RTKIs to optimize patient-specific cancer treatment and reduce adverse events.

Prognostic and therapeutic potential of STAT3: Opportunities and challenges in targeting HPV-mediated cervical carcinogenesis

Cervical cancer (CaCx) ranks as the fourth most prevalent cancer among women globally. Persistent infection of high-risk human papillomaviruses (HR-HPVs) is major etiological factor associated with CaCx. Signal Transducer and Activator of Transcription 3 (STAT3), a prominent member of the STAT family, has emerged as independent oncogenic driver. It is a target of many oncogenic viruses including HPV. How STAT3 influences HPV viral gene expression or gets affected by HPV is an area of active investigation. A better understanding of host-virus interaction will provide a prognostic and therapeutic window for CaCx control and management. In this comprehensive review, we delve into carcinogenic role of STAT3 in development of HPV-induced CaCx. With an emphasis on fascinating interplay between STAT3 and HPV genome, the review explores the diverse array of opportunities and challenges associated with this field to harness the prognostic and therapeutic potential of STAT3 in CaCx.

Exploring a repurposed candidate with dual hIDO1/hTDO2 inhibitory potential for anticancer efficacy identified through pharmacophore-based virtual screening and in vitro evaluation

Discovering effective anti-cancer agents poses a formidable challenge given the limited efficacy of current therapeutic modalities against various cancer types due to intrinsic resistance mechanisms. Cancer immunochemotherapy is an alternative strategy for breast cancer treatment and overcoming cancer resistance. Human Indoleamine 2,3-dioxygenase (hIDO1) and human Tryptophan 2,3-dioxygenase 2 (hTDO2) play pivotal roles in tryptophan metabolism, leading to the generation of kynurenine and other bioactive metabolites. This process facilitates the de novo synthesis of Nicotinamide Dinucleotide (NAD), promoting cancer resistance. This study identified a new dual hIDO1/hTDO2 inhibitor using a drug repurposing strategy of FDA-approved drugs. Herein, we delineate the development of a ligand-based pharmacophore model based on a training set of 12 compounds with reported hIDO1/hTDO2 inhibitory activity. We conducted a pharmacophore search followed by high-throughput virtual screening of 2568 FDA-approved drugs against both enzymes, resulting in ten hits, four of them with high potential of dual inhibitory activity. For further in silico and in vitro biological investigation, the anti-hypercholesterolemic drug Pitavastatin deemed the drug of choice in this study. Molecular dynamics (MD) simulations demonstrated that Pitavastatin forms stable complexes with both hIDO1 and hTDO2 receptors, providing a structural basis for its potential therapeutic efficacy. At nanomolar (nM) concentration, it exhibited remarkable in vitro enzyme inhibitory activity against both examined enzymes. Additionally, Pitavastatin demonstrated potent cytotoxic activity against BT-549, MCF-7, and HepG2 cell lines (IC50 = 16.82, 9.52, and 1.84 µM, respectively). Its anticancer activity was primarily due to the induction of G1/S phase arrest as discovered through cell cycle analysis of HepG2 cancer cells. Ultimately, treating HepG2 cancer cells with Pitavastatin affected significant activation of caspase-3 accompanied by down-regulation of cellular apoptotic biomarkers such as IDO, TDO, STAT3, P21, P27, IL-6, and AhR.

Bruceantinol targeting STAT3 exerts promising antitumor effects in in vitro and in vivo osteosarcoma models

Bruceantinol (BOL) is a quassinoid compound found in the fruits of Brucea javanica. Previous research has highlighted the manifold physiological and pharmacological activities of BOL. Notably, BOL has demonstrated antitumor cytotoxic and antibacterial effects, lending support to its potential as a promising therapeutic agent for various diseases. Despite being recognized as a potent antitumor inhibitor in multiple cancer types, its efficacy against osteosarcoma (OS) has not been elucidated. In this work, we investigated the antitumor properties of BOL against OS. Our findings showed that BOL significantly decreased the proliferation and migration of OS cells, induced apoptosis, and caused cell death without affecting the cell cycle. We further confirmed that BOL potently suppressed tumor growth in vivo. Mechanismly, we discovered that BOL directly bound to STAT3, and prevent the activation of STAT3 signaling at low nanomolar concentrations. Overall, our study demonstrated that BOL potently inhibited the growth and metastasis of OS, and efficiently suppressed STAT3 signaling pathway. These results suggest that BOL could be a promising therapeutic candidate for OS.

Chemosensitization of tumors via simultaneous delivery of STAT3 inhibitor and doxorubicin through HPMA copolymer-based nanotherapeutics with pH-sensitive activation

We synthesized three novel STAT3 inhibitors (S3iD1-S3iD3) possessing oxoheptanoic residue enabling linkage to HPMA copolymer carrier via a pH-sensitive hydrazone bond. HPMA copolymer conjugates bearing doxorubicin (Dox) and our STAT3 inhibitors were synthesized to evaluate the anticancer effect of Dox and STAT3 inhibitor co-delivery into tumors. S3iD1-3 and their copolymer-bound counterparts (P-S3iD1-P-S3iD3) showed considerable in vitro cytostatic activities in five mouse and human cancer cell lines with IC50 ~0.6-7.9 μM and 0.7-10.9 μM, respectively. S3iD2 and S3iD3 were confirmed to inhibit the STAT3 signaling pathway. The combination of HPMA copolymer-bound Dox (P-Dox) and P-S3iD3 at the dosage showing negligible toxicity demonstrated significant antitumor activity in B16F10 melanoma-bearing mice and completely cured 2 out of 15 mice. P-Dox alone had a significantly lower therapeutic activity with no completely cured mice. Thus, polymer conjugates bearing STAT3 inhibitors may be used for the chemosensitization of chemorefractory tumors.

An overview of the therapeutic strategies for neoplastic meningitis due to breast cancer: when and why?

INTRODUCTION

Neoplastic meningitis (NM), also known as leptomeningeal carcinomatosis, is characterized by the infiltration of tumor cells into the meninges, and poses a significant therapeutic challenge owing to its aggressive nature and limited treatment options. Breast cancer is a common cause of NM among solid tumors, further highlighting the urgent need to explore effective therapeutic strategies. This review aims to provide insights into the evolving landscape of NM therapy in breast cancer by collating existing research, evaluating current treatments, and identifying potential emerging therapeutic options.

AREAS COVERED

This review explores the clinical features, therapeutic strategies, recent advances, and challenges of managing NM in patients with breast cancer. Its management includes multimodal strategies, including systemic and intrathecal chemotherapy, radiation therapy, and supportive care. This review also emphasizes targeted drug options and optimal drug concentrations, and discusses emerging therapies. Additionally, it highlights the variability in treatment outcomes and the potential of combination regimens to effectively manage NM in breast cancer.

EXPERT OPINION

Challenges in treating NM include debates over clinical trial end points and the management of adverse effects. Drug resistance and low response rates are significant hurdles, particularly inHER2-negative breast cancer. The development of more precise and cost-effective medications with improved selectivity is crucial. Additionally, global efforts are needed for infrastructure development and cancer control considering the diverse nature of the disease.

Potential drug repurposing of ruxolitinib to inhibit the JAK/STAT pathway for the treatment of patients with epithelial ovarian cancer

AIM

This review aimed to describe the potential for therapeutic targeting of the JAK/STAT signaling pathway by repurposing the clinically-approved JAK inhibitor ruxolitinib in the patients with epithelial ovarian cancer (OC) setting.

METHODS

We reviewed publications that focus on the inhibition of the JAK/STAT pathway in hematological and solid malignancies including OC.

RESULTS

Preclinical studies showed that ruxolitinib effectively reduces OC cell viability and metastasis and enhances the anti-tumor activity of chemotherapy drugs. There are a number of recent clinical trials exploring the role of JAK/STAT inhibition in solid cancers including OC. Early results have not adequately supported efficacy in solid tumors. However, there are preclinical data and clinical studies supporting the use of ruxolitinib in combination with both chemotherapy and other targeted drugs in OC setting.

CONCLUSION

Inflammatory conditions and persistent activation of the JAK/STAT pathway are associated with tumourigenesis and chemoresistance, and therapeutic blockade of this pathway shows promising results. For women with OC, clinical investigation exploring the role of ruxolitinib in combination with chemotherapy agents or other targeted therapeutics is warranted.

Cancer-associated fibroblasts promote cancer stemness by inducing expression of the chromatin-modifying protein CBX4 in squamous cell carcinoma

The chromobox-containing protein CBX4 is an important regulator of epithelial cell proliferation and differentiation, and has been implicated in several cancer types. The cancer stem cell (CSC) population is a key driver of metastasis and recurrence. The undifferentiated, plastic state characteristic of CSCs relies on cues from the microenvironment. Cancer-associated fibroblasts (CAFs) are a major component of the microenvironment that can influence the CSC population through the secretion of extracellular matrix and a variety of growth factors. Here we show CBX4 is a critical regulator of the CSC phenotype in squamous cell carcinomas of the skin and hypopharynx. Moreover, CAFs can promote the expression of CBX4 in the CSC population through the secretion of interleukin-6 (IL-6). IL-6 activates JAK/STAT3 signaling to increase ∆Np63α-a key transcription factor that is essential for epithelial stem cell function and the maintenance of proliferative potential that is capable of regulating CBX4. Targeting the JAK/STAT3 axis or CBX4 directly suppresses the aggressive phenotype of CSCs and represents a novel opportunity for therapeutic intervention.

Novel Histopathological Biomarkers in Prostate Cancer: Implications and Perspectives

Prostate cancer (PCa) is the second most frequently diagnosed cancer in men. Despite the significant progress in cancer diagnosis and treatment over the last few years, the approach to disease detection and therapy still does not include histopathological biomarkers. The dissemination of PCa is strictly related to the creation of a premetastatic niche, which can be detected by altered levels of specific biomarkers. To date, the risk factors for biochemical recurrence include lymph node status, prostate-specific antigen (PSA), PSA density (PSAD), body mass index (BMI), pathological Gleason score, seminal vesicle invasion, extraprostatic extension, and intraductal carcinoma. In the future, biomarkers might represent another prognostic factor, as discussed in many studies. In this review, we focus on histopathological biomarkers (particularly CD169 macrophages, neuropilin-1, cofilin-1, interleukin-17, signal transducer and activator of transcription protein 3 (STAT3), LIM domain kinase 1 (LIMK1), CD15, AMACR, prostate-specific membrane antigen (PSMA), Appl1, Sortilin, Syndecan-1, and p63) and their potential application in decision making regarding the prognosis and treatment of PCa patients. We refer to studies that found a correlation between the levels of biomarkers and tumor characteristics as well as clinical outcomes. We also hypothesize about the potential use of histopathological markers as a target for novel immunotherapeutic drugs or targeted radionuclide therapy, which may be used as adjuvant therapy in the future.

Tumor microenvironmental modification by the current target therapy for head and neck squamous cell carcinoma

Current clinical and observational evidence supports the EXTREME regimen as one of the standards of care for patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) followed by the administration of immune checkpoint inhibitors (ICIs). In addition to the inhibition of the epidermal growth factor receptor (EGFR) pathway, cetuximab-mediated EGFR blockade has been shown to modulate tumor microenvironment (TME) characteristics, such as antibody-dependent cellular cytotoxicity (ADCC) activity, cytotoxic T-lymphocyte (CTL) infiltration into the tumor, anti-angiogenesis activity, and cytokine secretion via associated natural killer (NK) cells, etc.. On the other hand, there are reports that nivolumab affects the TME via Programmed cell death 1 (PD-1) inhibition, Interleukin-10 upregulation via T-cells, myeloid-derived suppressor cell-mediated immune escape induction, and tumor vessel perfusion by promoting CD8 + T-cell accumulation and Interferon-γ production in treatment-sensitive tumor cells. Actually, nivolumab administration can give T cells in the TME both immune superiority and inferiority. HNSCC treatment using cetuximab increases the frequency of FoxP3 + intratumoral effector regulatory T cells (Tregs) expressing CTL associated antigen (CTLA)-4, and targeting CTLA-4 + Tregs using ipilimumab restores the cytolytic function of NK cells, which mediate ADCC activity. Treg-mediated immune suppression also contributes to clinical response to cetuximab treatment, suggesting the possibility of the addition of ipilimumab or the use of other Treg ablation strategies to promote antitumor immunity. Moreover, also in hyper progression disease (HPD), intratumoral frequency of FoxP3 + effector Tregs expressing CTLA-4 is increased. Therefore, combination treatment with cetuximab plus anti-CTLA-4 antibody ipilimumab for HNSCC and this combination therapy after nivolumab administration for HPD may be expected to result in a higher tumor-control response. Based on the above evidence, we here suggest the efficacy of using these therapeutic strategies for patients with local-advanced, recurrent, and metastatic HNSCC and patients who do not respond well to nivolumab administration.

Targeting Tumor Microenvironment Akt Signaling Represents a Potential Therapeutic Strategy for Aggressive Thyroid Cancer

Effects of the tumor microenvironment (TME) stromal cells on progression in thyroid cancer are largely unexplored. Elucidating the effects and underlying mechanisms may facilitate the development of targeting therapy for aggressive cases of this disease. In this study, we investigated the impact of TME stromal cells on cancer stem-like cells (CSCs) in patient-relevant contexts where applying in vitro assays and xenograft models uncovered contributions of TME stromal cells to thyroid cancer progression. We found that TME stromal cells can enhance CSC self-renewal and invasiveness mainly via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway. The disruption of Akt signaling could diminish the impact of TME stromal cells on CSC aggressiveness in vitro and reduce CSC tumorigenesis and metastasis in xenografts. Notably, disrupting Akt signaling did not cause detectable alterations in tumor histology and gene expression of major stromal components while it produced therapeutic benefits. In addition, using a clinical cohort, we discovered that papillary thyroid carcinomas with lymph node metastasis are more likely to have elevated Akt signaling compared with the ones without metastasis, suggesting the relevance of Akt-targeting. Overall, our results identify PI3K/Akt pathway-engaged contributions of TME stromal cells to thyroid tumor disease progression, illuminating TME Akt signaling as a therapeutic target in aggressive thyroid cancer.

G protein-coupled bile acid receptor 1 reduced hepatic immune response and inhibited NFκB, PI3K/AKT, and PKC/P38 MAPK signaling pathway in hybrid grouper

The mammalian G protein-coupled bile acid receptor 1 (TGR5) is involved in the inflammatory response. However, the functions of TGR5 in the immune response of fish remain unclear. In this study, the full-length sequence of tgr5 from hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) was cloned, and the function of TGR5 in the immune response was explored. The results showed that the ORF of tgr5 gene in hybrid grouper was 1029 bp and encoded 342 amino acids. Activation of TGR5 by INT-777 significantly decreased the activities and mRNA expression of TNFα and IL1β, whereas inhibition of TGR5 by SBI-115 showed the opposite effect. SBI-115 treatment significantly increased the expression of phosphorylated inhibitor κB α (p-IKBα) protein. After the INT-777 treatment, the concentration of protein kinase C (PKC) and expression of the p38 mitogen-activated protein kinases (p38a), p38b and p38c, were significantly decreased in vivo. INT-777 agonist significantly decreased the expression of phosphorylated phosphoinositide 3-kinase (p-PI3K) protein and the ratio of phosphorylated and nonphosphorylated serine/threonine-protein kinase (p-AKT/AKT). In conclusion, activation of hepatic TGR5 inhibited the PKC/P38 MAPK, PI3K/AKT, NFκB signaling pathway and improved hepatic immune responses of hybrid grouper in vivo and in vitro.

JAK/STAT pathway: Extracellular signals, diseases, immunity, and therapeutic regimens

Janus kinase/signal transduction and transcription activation (JAK/STAT) pathways were originally thought to be intracellular signaling pathways that mediate cytokine signals in mammals. Existing studies show that the JAK/STAT pathway regulates the downstream signaling of numerous membrane proteins such as such as G-protein-associated receptors, integrins and so on. Mounting evidence shows that the JAK/STAT pathways play an important role in human disease pathology and pharmacological mechanism. The JAK/STAT pathways are related to aspects of all aspects of the immune system function, such as fighting infection, maintaining immune tolerance, strengthening barrier function, and cancer prevention, which are all important factors involved in immune response. In addition, the JAK/STAT pathways play an important role in extracellular mechanistic signaling and might be an important mediator of mechanistic signals that influence disease progression, immune environment. Therefore, it is important to understand the mechanism of the JAK/STAT pathways, which provides ideas for us to design more drugs targeting diseases based on the JAK/STAT pathway. In this review, we discuss the role of the JAK/STAT pathway in mechanistic signaling, disease progression, immune environment, and therapeutic targets.

Pim-1 kinase is a positive feedback regulator of the senescent lung fibroblast inflammatory secretome

Cellular senescence is emerging as a driver of idiopathic pulmonary fibrosis (IPF), a progressive and fatal disease with limited effective therapies. The senescence-associated secretory phenotype (SASP), involving the release of inflammatory cytokines and profibrotic growth factors by senescent cells, is thought to be a product of multiple cell types in IPF, including lung fibroblasts. NF-κB is a master regulator of the SASP, and its activity depends on the phosphorylation of p65/RelA. The purpose of this study was to assess the role of Pim-1 kinase as a driver of NF-κB-induced production of inflammatory cytokines from low-passage IPF fibroblast cultures displaying markers of senescence. Our results demonstrate that Pim-1 kinase phosphorylates p65/RelA, activating NF-κB activity and enhancing IL-6 production, which in turn amplifies the expression of PIM1, generating a positive feedback loop. In addition, targeting Pim-1 kinase with a small molecule inhibitor dramatically inhibited the expression of a broad array of cytokines and chemokines in IPF-derived fibroblasts. Furthermore, we provide evidence that Pim-1 overexpression in low-passage human lung fibroblasts is sufficient to drive premature senescence, in vitro. These findings highlight the therapeutic potential of targeting Pim-1 kinase to reprogram the secretome of senescent fibroblasts and halt IPF progression.

Molecular mechanisms underlying the action of carcinogens in gastric cancer with a glimpse into targeted therapy

BACKGROUND

Gastric cancer imposes a substantial global health burden despite its overall incidence decrease. A broad spectrum of inherited, environmental and infectious factors contributes to the development of gastric cancer. A profound understanding of the molecular underpinnings of gastric cancer has lagged compared to several other tumors with similar incidence and morbidity rates, owing to our limited knowledge of the role of carcinogens in this malignancy. The International Agency for Research on Cancer (IARC) has classified gastric carcinogenic agents into four groups based on scientific evidence from human and experimental animal studies. This review aims to explore the potential comprehensive molecular and biological impacts of carcinogens on gastric cancer development and their interactions and interferences with various cellular signaling pathways.

CONCLUSIONS

In this review, we highlight recent clinical trial data reported in the literature dealing with different ways to target various carcinogens in gastric cancer. Moreover, we touch upon other multidisciplinary therapeutic approaches such as surgery, adjuvant and neoadjuvant chemotherapy. Rational clinical trials focusing on identifying suitable patient populations are imperative to the success of single-agent therapeutics. Novel insights regarding signaling pathways that regulate gastric cancer can potentially improve treatment responses to targeted therapy alone or in combination with other/conventional treatments. Preventive strategies such as control of H. pylori infection through eradication or immunization as well as dietary habit and lifestyle changes may reduce the incidence of this multifactorial disease, especially in high prevalence areas. Further in-depth understanding of the molecular mechanisms involved in the role of carcinogenic agents in gastric cancer development may offer valuable information and update state-of-the-art resources for physicians and researchers to explore novel ways to combat this disease, from bench to bedside. A schematic outlining of the interaction between gastric carcinogenic agents and intracellular pathways in gastric cancer H. pylori stimulates multiple intracellular pathways, including PI3K/AKT, NF-κB, Wnt, Shh, Ras/Raf, c-MET, and JAK/STAT, leading to epithelial cell proliferation and differentiation, apoptosis, survival, motility, and inflammatory cytokine release. EBV can stimulate intracellular pathways such as the PI3K/Akt, RAS/RAF, JAK/STAT, Notch, TGF-β, and NF-κB, leading to cell survival and motility, proliferation, invasion, metastasis, and the transcription of anti-apoptotic genes and pro-inflammatory cytokines. Nicotine and alcohol can lead to angiogenesis, metastasis, survival, proliferation, pro-inflammatory, migration, and chemotactic by stimulating various intracellular signaling pathways such as PI3K/AKT, NF-κB, Ras/Raf, ROS, and JAK/STAT. Processed meat contains numerous carcinogenic compounds that affect multiple intracellular pathways such as sGC/cGMP, p38 MAPK, ERK, and PI3K/AKT, leading to anti-apoptosis, angiogenesis, metastasis, inflammatory responses, proliferation, and invasion. Lead compounds may interact with multiple signaling pathways such as PI3K/AKT, NF-κB, Ras/Raf, DNA methylation-dependent, and epigenetic-dependent, leading to tumorigenesis, carcinogenesis, malignancy, angiogenesis, DNA hypermethylation, cell survival, and cell proliferation. Stimulating signaling pathways such as PI3K/Akt, RAS/RAF, JAK/STAT, WNT, TGF-β, EGF, FGFR2, and E-cadherin through UV ionizing radiation leads to cell survival, proliferation, and immortalization in gastric cancer. The consequence of PI3K/AKT, NF-κB, Ras/Raf, ROS, JAK/STAT, and WNT signaling stimulation by the carcinogenic component of Pickled vegetables and salted fish is the Warburg effect, tumorigenesis, angiogenesis, proliferation, inflammatory response, and migration.

Chlorogenic acid enhances alveolar macrophages phagocytosis in acute respiratory distress syndrome by activating G protein-coupled receptor 37 (GPR 37)

BACKGROUND

Impaired alveolar macrophages phagocytosis can contribute to pathogenesis of acute respiratory distress syndrome (ARDS) and negatively impacts clinical outcomes. Chlorogenic acid (CGA) is a naturally occurring polyphenolic compound with potential anti-inflammatory and antioxidant bioactivities. Studies have shown that CGA plays a protective role in ARDS, however, the precise protective mechanism of CGA against ARDS, is still unclear.

PURPOSE

The aim of this study was to investigate whether CGA enhances alveolar macrophages phagocytosis to attenuate lung injury during ARDS.

METHODS

RAW264.7 cells were stimulated with lipopolysaccharides (100 μg/ml for 24 h) and treated with CGA (100, 200, and 400 μM CGA for 1 h) to measure pro-inflammatory cytokine levels, GPR37 expression and macrophages phagocytosis. Mouse models of ARDS induced by cecal ligation and perforation (CLP) surgery were treated with CGA (100 or 200 mg/kg) to investigate lung inflammatory injury and alveolar macrophages phagocytosis. Computational modeling was performed to examine potential binding sites of G protein-coupled receptor 37 (GPR37) with CGA, and the results were validated by interfering with the binding sites.

RESULT

In vitro, CGA notably ameliorated inflammatory response and increased phagocytosis in lipopolysaccharides-induced RAW264.7 cells. In vivo, CGA administration significantly alleviated lung inflammatory injury, decreased the bacteria load in the lung, promoted alveolar macrophages phagocytosis and improved the survival rate in mice with CLP-induced ARDS. Moreover, CGA markedly upregulated the expression of GPR37 in vivo and in vitro. However, the protective effect of CGA against ARDS were reversed after silencing the expression of GPR37.

CONCLUSION

CGA has a protective effect against ARDS and may enhance alveolar macrophages phagocytosis and attenuate lung inflammatory injury by upregulating GPR37 expression.

Ciclopirox drives growth arrest and autophagic cell death through STAT3 in gastric cancer cells

Ciclopirox (CPX), an antifungal drug, has recently been identified as a promising agent for cancer treatment. However, the effects and underlying mechanism of CPX as an antitumor agent of gastric cancer (GC) remain largely unknown. Here, we found that CPX dramatically suppresses GC xenograft growth in vitro via inhibiting proliferation and stimulating autophagic cell death rather than apoptosis. Moreover, CPX (20 mg/kg, intraperitoneally) substantially inhibits GC xenograft tumor growth in vivo. Mechanistically, CPX promotes growth arrest and autophagic cell death through suppressing the phosphorylation of signal transducers and activators of transcription 3 (STAT3) at tyrosine 705 (Tyr705) and serine 727 (Ser727) sites, respectively. Additionally, CPX induces STAT3 ubiquitination, which subsequently leads to a decrease in the p-STAT3 (Ser727) level. On the other hand, CPX represses the p-STAT3 (Tyr705) level via p-Src (Tyr416) inhibition. Collectively, our findings unmask a novel mechanism by which CPX regulates growth and autophagic cell death in GC cells via regulating the phosphorylation of STAT3 both at Tyr705 and Ser727 residues, and suggest that CPX may be a potential treatment for GC.

STAT3 Activation as a Predictive Biomarker for Ruxolitinib Response in Head and Neck Cancer

PURPOSE

Increased activity of STAT3 is associated with progression of head and neck squamous cell carcinoma (HNSCC). Upstream activators of STAT3, such as JAKs, represent potential targets for therapy of solid tumors, including HNSCC. In this study, we investigated the anticancer effects of ruxolitinib, a clinical JAK1/2 inhibitor, in HNSCC preclinical models, including patient-derived xenografts (PDX) from patients treated on a window-of-opportunity trial.

EXPERIMENTAL DESIGN

HNSCC cell lines were treated with ruxolitinib, and the impact on activated STAT3 levels, cell growth, and colony formation was assessed. PDXs were generated from patients with HNSCC who received a brief course of neoadjuvant ruxolitinib on a clinical trial. The impact of ruxolitinib on tumor growth and STAT3 activation was assessed.

RESULTS

Ruxolitinib inhibited STAT3 activation, cellular growth, and colony formation of HNSCC cell lines. Ruxolitinib treatment of mice bearing an HNSCC cell line-derived xenograft significantly inhibited tumor growth compared with vehicle-treated controls. The response of HNSCC PDXs derived from patients on the clinical trial mirrored the responses seen in the neoadjuvant setting. Baseline active STAT3 (pSTAT3) and total STAT3 levels were lower, and ruxolitinib inhibited STAT3 activation in a PDX from a patient whose disease was stable on ruxolitinib, compared with a PDX from a patient whose disease progressed on ruxolitinib and where ruxolitinib treatment had minimal impact on STAT3 activation.

CONCLUSIONS

Ruxolitinib exhibits antitumor effects in HNSCC preclinical models. Baseline pSTAT3 or total STAT3 levels in the tumor may serve as predictive biomarkers to identify patients most likely to respond to ruxolitinib.

Role of STAT3 in the initiation, progression, proliferation and metastasis of breast cancer and strategies to deliver JAK and STAT3 inhibitors

INTRODUCTION

Breast cancer (BC) accounts for the majority of cancers among the female population. Anomalous activation of various signaling pathways has become an issue of concern. The JAK-STAT signaling pathway is activated in numerous cancers, including BC. STAT3 is widely involved in BCs, as 40 % of BCs display phosphorylated STAT3. JAK-STAT signaling is crucial for proliferation, survival, metastasis and other cellular events associated with the tumor microenvironment. Hence, targeting this pathway has become an area of interest among researchers.

KEY FINDINGS

This review article focuses on the role of STAT3 in the initiation, proliferation, progression and metastasis of BC. The roles of various phytochemicals, synthetic molecules and biologicals against JAK-STAT and STAT3 in various cancers have been discussed, with special emphasis on BC.

SIGNIFICANCE

JAK and STAT3 are involved in various phases from initiation to metastasis, and targeting this pathway is a promising approach to inhibit the various stages of BC development and to prevent metastasis. A number of phytochemicals and synthetic and biological molecules have demonstrated potential inhibitory effects on JAK and STAT3, thereby paving the way for the development of better therapeutics against BC.

Role of Nrf2, STAT3, and Src as Molecular Targets for Cancer Chemoprevention

Cancer is a complex and multistage disease that affects various intracellular pathways, leading to rapid cell proliferation, angiogenesis, cell motility, and migration, supported by antiapoptotic mechanisms. Chemoprevention is a new strategy to counteract cancer; to either prevent its incidence or suppress its progression. In this strategy, chemopreventive agents target molecules involved in multiple pathways of cancer initiation and progression. Nrf2, STAT3, and Src are promising molecular candidates that could be targeted for chemoprevention. Nrf2 is involved in the expression of antioxidant and phase II metabolizing enzymes, which have direct antiproliferative action as well as indirect activities of reducing oxidative stress and eliminating carcinogens. Similarly, its cross-talk with NF-κB has great anti-inflammatory potential, which can be utilized in inflammation-induced/associated cancers. STAT3, on the other hand, is involved in multiple pathways of cancer initiation and progression. Activation, phosphorylation, dimerization, and nuclear translocation are associated with tumor cell proliferation and angiogenesis. Src, being the first oncogene to be discovered, is important due to its convergence with many upstream stimuli, its cross-talk with other potential molecular targets, such as STAT3, and its ability to modify the cell cytoskeleton, making it important in cancer invasion and metastasis. Therefore, the development of natural/synthetic molecules and/or design of a regimen that can reduce oxidative stress and inflammation in the tumor microenvironment and stop multiple cellular targets in cancer to stop its initiation or retard its progression can form newer chemopreventive agents.

Discovery, Significance, and Utility of JAK2 Mutation in Squamous Cell Carcinoma of the Lung

Lung cancer continues to be the leading cause of cancer-related deaths worldwide. Many studies show lung cancer is a histologically and molecularly heterogeneous group, even within the same histological subtype. Liquid biopsies are a new tool that can identify targetable genomic mutations and impact management. JAK2 p.V617F is a mutation commonly found in myeloproliferative neoplasms but rarely identified in non-small cell lung cancer (NSCLCs). The significance of Janus Kinase (JAK2) mutation in lung cancer is not clearly understood. However, it is thought that it may have a role in treating solid tumors, such as lung cancer. We present two cases of patients diagnosed with NSCLC who were discovered to have JAK2 V617F mutation on liquid biopsy.

O-methylated flavonol as a multi-kinase inhibitor of leukemogenic kinases exhibits a potential treatment for acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is a heterogeneous disease with poor overall survival characterized by various genetic changes. The continuous activation of oncogenic pathways leads to the development of drug resistance and limits current therapeutic efficacy. Therefore, a multi-targeting inhibitor may overcome drug resistance observed in AML treatment. Recently, groups of flavonoids, such as flavones and flavonols, have been shown to inhibit a variety of kinase activities, which provides potential opportunities for further anticancer applications.

PURPOSE

In this study, we evaluated the anticancer effects of flavonoid compounds collected from our in-house library and investigated their potential anticancer mechanisms by targeting multiple kinases for inhibition in AML cells.

METHODS

The cytotoxic effect of the compounds was detected by cell viability assays. The kinase inhibitory activity of the selected compound was detected by kinase-based and cell-based assays. The binding conformation and interactions were investigated by molecular docking analysis. Flow cytometry was used to evaluate the cell cycle distribution and cell apoptosis. The protein and gene expression were estimated by western blotting and qPCR, respectively.

RESULTS

In this study, an O-methylated flavonol (compound 11) was found to possess remarkable cytotoxic activity against AML cells compared to treatment in other cancer cell lines. The compound was demonstrated to act against multiple kinases, which play critical roles in survival signaling in AML, including FLT3, MNK2, RSK, DYRK2 and JAK2 with IC₅₀ values of 1 - 2 μM. Compared to our previous flavonoid compounds, which only showed inhibitions against MNKs or FLT3, compound 11 exhibited multiple kinase inhibitory abilities. Moreover, compound 11 showed effectiveness in inhibiting internal tandem duplications of FLT3 (FLT3-ITDs), which accounts for 25% of AML cases. The interactions between compound 11 and targeted kinases were investigated by molecular docking analysis. Mechanically, compound 11 caused dose-dependent accumulation of leukemic cells at the G₀/G₁ phase and followed by the cells undergoing apoptosis.

CONCLUSION

O-methylated flavonol, compound 11, can target multiple kinases, which may provide potential opportunities for the development of novel therapeutics for drug-resistant AMLs. This work provides a good starting point for further compound optimization.

Advances in Immunosuppressive Agents Based on Signal Pathway

Immune abnormality involves in various diseases, such as infection, allergic diseases, autoimmune diseases, as well as transplantation. Several signal pathways have been demonstrated to play a central role in the immune response, including JAK/STAT, NF-κB, PI3K/AKT-mTOR, MAPK, and Keap1/Nrf2/ARE pathway, in which multiple targets have been used to develop immunosuppressive agents. In recent years, varieties of immunosuppressive agents have been approved for clinical use, such as the JAK inhibitor tofacitinib and the mTOR inhibitor everolimus, which have shown good therapeutic effects. Additionally, many immunosuppressive agents are still in clinical trials or preclinical studies. In this review, we classified the immunosuppressive agents according to the immunopharmacological mechanisms, and summarized the phase of immunosuppressive agents.

Canonical and noncanonical regulatory roles for JAK2 in the pathogenesis of rheumatoid arthritis-associated interstitial lung disease and idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) and rheumatoid arthritis-associated interstitial lung disease (RA-ILD) are two fibrotic interstitial lung diseases that share the usual interstitial pneumonia (UIP) injury pattern. Here, we report that RNA sequencing of lung biopsies from patients with RA-ILD and IPF revealed shared and distinct disease-causing pathways. Analysis of transcriptomic data identified a JAK2 related JAK/STAT signaling pathway gene signature that distinguishes RA-UIP from idiopathic UIP. This was further confirmed by immunohistostaining, which identified JAK2 phosphorylation with two distinct forms of activation: a cytoplasmic form of JAK2 activation in most IPF cases (13/20) and a nuclear form of p-JAK2 in RA-UIP (5/5) and a minority of IPF (6/20) cases. Further immunohistostaining identified STAT5A&B as the downstream transcriptional activator for JAK2-mediated canonical signal transduction and phosphorylation of Tyr41 on histone H3 (H3Y41ph) as the downstream epigenetic regulation site for JAK2-mediated noncanonical signal transduction. Gene Set Enrichment Analysis (GSEA) of the RNA-Seq data further supported this shared pathogenic mechanism for the two diseases with the enrichment of STAT5A&B target gene sets as well as the JAK2 regulated H3Y41ph target gene set. This regulatory role of JAK2 in the pathogenesis of pulmonary fibrosis was further demonstrated by the attenuation of bleomycin-induced murine pulmonary fibrosis using a JAK2-selective pharmacological inhibitor CEP33779. In vitro studies with normal and IPF derived lung fibroblasts revealed a central role for JAK2 as an essential intermediary molecule in TGF-β-mediated myofibroblast trans-differentiation, proliferation, and extracellular matrix protein production. These observations support a crucial role for JAK2 as an intermediary molecule in fibrotic lung disease development.

The Emerging Role of Janus Kinase Inhibitors in the Treatment of Cancer

Cancer is a leading cause of death worldwide. The Janus kinase (JAK) signal transducer and activator of transcription (STAT) signalling pathway is activated abnormally, which promotes carcinogenesis. Several cytokines are important cancer drivers. These proteins bind to receptors and use the Janus kinase (JAK) and STAT pathways to communicate their responses. Cancer risks are linked to genetic differences in the JAK-STAT system. JAK inhibitors have shown to reduce STAT initiation, tissue propagation, and cell existence in preclinical investigations in solid tumour cell line models. JAK inhibitors, notably ruxolitinib, a, JAK1 or 2 blockers, make cell lines and mouse models more susceptible to radiotherapy, biological response modifier therapy, and oncolytic viral treatment. Numerous JAK antagonists have been or are now being evaluated in cancerous patients as monotherapy or by combining with other drugs in clinical studies. In preclinical investigations, certain JAK inhibitors showed promise anticancer effects; however, clinical trials explicitly evaluating their effectiveness against the JAK/STAT system in solid tumours have yet to be completed. JAK inhibition is a promising strategy to target the JAK/STAT system in solid tumours, and it deserves to be tested further in clinical studies. The function of directing Janus kinases (JAKs), an upstream accelerator of STATs, as a technique for lowering STAT activity in various malignant circumstances is summarized in this article, which will help scientists to generate more specific drug molecules in future.

Potential therapies for immune-related adverse events associated with immune checkpoint inhibition: from monoclonal antibodies to kinase inhibition

The therapeutic benefits of immune checkpoint inhibitors (ICIs), which enable antitumor immune responses, can be tempered by unwanted immune-related adverse events (irAEs). Treatment recommendations stratified by irAE phenotype and immunohistopathological findings have only recently been proposed and are often based on those used in primary autoimmune diseases, including targeting of specific proinflammatory cytokines with monoclonal antibodies. Increasing evidence supports the use of such antibody-based strategies as effective steroid-sparing treatments, although the therapies themselves may be associated with additional drug toxicities and reduced ICI efficacy. Kinases are key contributors to the adaptive and innate responses that drive primary autoimmune diseases and irAEs. The janus kinase/signal transducer and activator of transcription, Bruton’s tyrosine kinase, and mitogen-activated protein kinase-interacting serine/threonine protein kinases 1 and 2 pathways are also critical to tumor progression and have important roles in cells of the tumor microenvironment. Herein, we review the histopathological, biological, and clinical evidence to support specific monoclonal antibodies and kinase inhibition as management strategies for irAEs.

The involvement of JAK/STAT signaling pathway in the treatment of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder in which inflammation and oxidative stress play key etiopathological role. The pathology of PD brain is characterized by inclusions of aggregated α-synuclein (α-SYN) in the cytoplasmic region of neurons. Clinical evidence suggests that stimulation of pro-inflammatory cytokines leads to neuroinflammation in the affected brain regions. Upon neuroinflammation, the Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) signaling pathway, and other transcription factors such as nuclear factor κB (NF-κB), NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3), mammalian target of rapamycin (mTOR), and toll-like receptors (TLRs) are upregulated and induce the microglial activation, contributing to PD via dopaminergic neuron autophagy. Aberrant activation or phosphorylation of the components of JAK/STAT signaling pathway has been implicated in increased transcription of the inflammation-associated genes and many neurodegenerative disorders such as PD. Interferon gamma (IFN-γ), and interleukine (IL)-6 are two of the most potent activators of the JAK/STAT pathway, and it was shown to be elevated in PD. Stimulation of microglial cell with aggregated α-SYN results in production of nitric oxide (NO), tumor necrosis factor (TNF)-α, and IL-1β in PD. Dysregulation of the JAK/STAT in PD and its involvement in various inflammatory pathways make it a promising PD therapy approach. So far, a variety of synthetic or natural small-molecule JAK inhibitors (Jakinibs) have been found promising in managing a spectrum of ailments, many of which are in preclinical research or clinical trials. Herein, we provided a perspective on the function of the JAK/STAT signaling pathway in PD progression and gathered data that describe the rationale evidence on the potential application of Jakinibs to improve neuroinflammation in PD.

Multicellular Effects of STAT3 in Non-small Cell Lung Cancer: Mechanistic Insights and Therapeutic Opportunities

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and accounts for 85% of lung cancer cases. Aberrant activation of the Signal Transducer and Activator of Transcription 3 (STAT3) is frequently observed in NSCLC and is associated with a poor prognosis. Pre-clinical studies have revealed an unequivocal role for tumor cell-intrinsic and extrinsic STAT3 signaling in NSCLC by promoting angiogenesis, cell survival, cancer cell stemness, drug resistance, and evasion of anti-tumor immunity. Several STAT3-targeting strategies have also been investigated in pre-clinical models, and include preventing upstream receptor/ligand interactions, promoting the degradation of STAT3 mRNA, and interfering with STAT3 DNA binding. In this review, we discuss the molecular and immunological mechanisms by which persistent STAT3 activation promotes NSCLC development, and the utility of STAT3 as a prognostic and predictive biomarker in NSCLC. We also provide a comprehensive update of STAT3-targeting therapies that are currently undergoing clinical evaluation, and discuss the challenges associated with these treatment modalities in human patients.

Bridging Radiotherapy to Immunotherapy: The IFN-JAK-STAT Axis

The unprecedented successes of immunotherapies (IOs) including immune checkpoint blockers (ICBs) and adoptive T-cell therapy (ACT) in patients with late-stage cancer provide proof-of-principle evidence that harnessing the immune system, in particular T cells, can be an effective approach to eradicate cancer. This instills strong interests in understanding the immunomodulatory effects of radiotherapy (RT), an area that was actually investigated more than a century ago but had been largely ignored for many decades. With the "newly" discovered immunogenic responses from RT, numerous endeavors have been undertaken to combine RT with IOs, in order to bolster anti-tumor immunity. However, the underlying mechanisms are not well defined, which is a subject of much investigation. We therefore conducted a systematic literature search on the molecular underpinnings of RT-induced immunomodulation and IOs, which identified the IFN-JAK-STAT pathway as a major regulator. Our further analysis of relevant studies revealed that the signaling strength and duration of this pathway in response to RT and IOs may determine eventual immunological outcomes. We propose that strategic targeting of this axis can boost the immunostimulatory effects of RT and radiosensitizing effects of IOs, thereby promoting the efficacy of combination therapy of RT and IOs.

A phase 1b study of erlotinib and momelotinib for the treatment of EGFR-mutated, tyrosine kinase inhibitor-naive metastatic non-small cell lung cancer

INTRODUCTION

Preclinical evidence suggests the feedforward cytokine loop of interleukin-6/Janus kinases (JAK)/STAT3 plays a role in epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) resistance in EGFR-mutated non-small cell lung cancer (NSCLC).

METHODS

In this phase 1b study, the JAK1/2 and TANK-binding kinase 1 (TBK1) inhibitor momelotinib was evaluated in combination with erlotinib in patients with EGFR TKI-naive, EGFR-mutated NSCLC. After erlotinib lead-in (50, 75, 100, or 150 mg oral daily [QD]), momelotinib was combined and dose escalated in a 3 + 3 study design. The primary endpoint of maximum tolerated dose (MTD) of momelotinib was determined based on the incidence of dose-limiting toxicities (DLTs) during the first 28-day cycle. Secondary endpoints included efficacy and pharmacokinetics (PK).

RESULTS

Eleven patients were enrolled across 3 dose levels of momelotinib (100 mg QD, 200 mg QD, and 100 mg twice daily [BID]). The MTD was momelotinib 200 mg QD in combination with erlotinib. Two DLTs of grade 4 neutropenia without fever and grade 3 diarrhea occurred at momelotinib 100 mg BID. Most common treatment-emergent adverse events included diarrhea, dry skin, fatigue, and decreased appetite; the vast majority being grades 1-2. The overall response rate was 54.5% (90% CI 27.1-80.0; all partial) and median progression-free survival was 9.2 months (90% CI 6.2-12.4). Momelotinib did not affect the PK of erlotinib.

CONCLUSIONS

The JAK1/2 and TBK1 inhibitor momelotinib in combination with erlotinib did not appear to enhance benefit over the historical data of erlotinib monotherapy in patients with EGFR-mutated NSCLC. CLINICALTRIALS.

GOV IDENTIFIER

NCT02206763.

Plasmacytoid dendritic cell activation is dependent on coordinated expression of distinct amino acid transporters

Human plasmacytoid dendritic cells (pDCs) are interleukin-3 (IL-3)-dependent cells implicated in autoimmunity, but the role of IL-3 in pDC biology is poorly understood. We found that IL-3-induced Janus kinase 2-dependent expression of SLC7A5 and SLC3A2, which comprise the large neutral amino acid transporter, was required for mammalian target of rapamycin complex 1 (mTORC1) nutrient sensor activation in response to toll-like receptor agonists. mTORC1 facilitated increased anabolic activity resulting in type I interferon, tumor necrosis factor, and chemokine production and the expression of the cystine transporter SLC7A11. Loss of function of these amino acid transporters synergistically blocked cytokine production by pDCs. Comparison of in vitro-activated pDCs with those from lupus nephritis lesions identified not only SLC7A5, SLC3A2, and SLC7A11 but also ectonucleotide pyrophosphatase-phosphodiesterase 2 (ENPP2) as components of a shared transcriptional signature, and ENPP2 inhibition also blocked cytokine production. Our data identify additional therapeutic targets for autoimmune diseases in which pDCs are implicated.

The IL6-like Cytokine Family: Role and Biomarker Potential in Breast Cancer

IL6-like cytokines are a family of regulators with a complex, pleiotropic role in both the healthy organism, where they regulate immunity and homeostasis, and in different diseases, including cancer. Here we summarise how these cytokines exert their effect through the shared signal transducer IL6ST (gp130) and we review the extensive evidence on the role that different members of this family play in breast cancer. Additionally, we discuss how the different cytokines, their related receptors and downstream effectors, as well as specific polymorphisms in these molecules, can serve as predictive or prognostic biomarkers with the potential for clinical application in breast cancer. Lastly, we also discuss how our increasing understanding of this complex signalling axis presents promising opportunities for the development or repurposing of therapeutic strategies against cancer and, specifically, breast neoplasms.

Second-Generation Jak2 Inhibitors for Advanced Prostate Cancer: Are We Ready for Clinical Development?

Simple Summary

Prostate Cancer (PC) is currently estimated to affect 1 in 9 men and is the second leading cause of cancer in men in the US. While androgen deprivation therapy, which targets the androgen receptor, is one of the front-line therapies for advanced PC and for recurrence of organ-confined PC treated with surgery, lethal castrate-resistant PC develops consistently in patients. PC is a multi-focal cancer with different grade carcinoma areas presenting simultaneously. Jak2-Stat5 signaling pathway has emerged as a potentially highly effective molecular target in PCs with positive areas for activated Stat5 protein. Activated Jak2-Stat5 signaling can be readily targeted by the second-generation Jak2-inhibitors that have been developed for myeloproliferative and autoimmune disorders and hematological malignancies. In this review, we analyze and summarize the Jak2 inhibitors that are currently in preclinical and clinical development.

Abstract

Androgen deprivation therapy (ADT) for metastatic and high-risk prostate cancer (PC) inhibits growth pathways driven by the androgen receptor (AR). Over time, ADT leads to the emergence of lethal castrate-resistant PC (CRPC), which is consistently caused by an acquired ability of tumors to re-activate AR. This has led to the development of second-generation anti-androgens that more effectively antagonize AR, such as enzalutamide (ENZ). However, the resistance of CRPC to ENZ develops rapidly. Studies utilizing preclinical models of PC have established that inhibition of the Jak2-Stat5 signaling leads to extensive PC cell apoptosis and decreased tumor growth. In large clinical cohorts, Jak2-Stat5 activity predicts PC progression and recurrence. Recently, Jak2-Stat5 signaling was demonstrated to induce ENZ-resistant PC growth in preclinical PC models, further emphasizing the importance of Jak2-Stat5 for therapeutic targeting for advanced PC. The discovery of the Jak2V617F somatic mutation in myeloproliferative disorders triggered the rapid development of Jak1/2-specific inhibitors for a variety of myeloproliferative and auto-immune disorders as well as hematological malignancies. Here, we review Jak2 inhibitors targeting the mutated Jak2V617F vs. wild type (WT)-Jak2 that are currently in the development pipeline. Among these 35 compounds with documented Jak2 inhibitory activity, those with potency against WT-Jak2 hold strong potential for advanced PC therapy.

Inhibition of Janus Kinase 1 synergizes docetaxel sensitivity in prostate cancer cells

Prostate cancer (PCa) is the second most common malignancy and is the fifth leading cause of cancer mortality among men globally. Docetaxel-based therapy remains the first-line treatment for metastatic castration-resistant prostate cancer. However, dose-limiting toxicity including neutropenia, myelosuppression and neurotoxicity is the major reason for docetaxel dose reductions and fewer cycles administered, despite a recent study showing a clear survival benefit with increased total number of docetaxel cycles in PCa patients. Although previous studies have attempted to improve the efficacy and reduce docetaxel toxicity through drug combination, no drug has yet demonstrated improved overall survival in clinical trial, highlighting the challenges of improving the activity of docetaxel monotherapy in PCa. Herein, we identified 15 lethality hits for which inhibition could enhance docetaxel sensitivity in PCa cells via a high-throughput kinome-wide loss-of-function screen. Further drug-gene interactions analyses identified Janus kinase 1 (JAK1) as a viable druggable target with existing experimental inhibitors and FDA-approved drugs. We demonstrated that depletion of endogenous JAK1 enhanced docetaxel-induced apoptosis in PCa cells. Furthermore, inhibition of JAK1/2 by baricitinib and ruxolitinib synergizes docetaxel sensitivity in both androgen receptor (AR)-negative DU145 and PC3 cells, but not in the AR-positive LNCaP cells. In contrast, no synergistic effects were observed in cells treated with JAK2-specific inhibitor, fedratinib, suggesting that the synergistic effects are mainly mediated through JAK1 inhibition. In conclusion, the combination therapy with JAK1 inhibitors and docetaxel could be a useful therapeutic strategy in the treatment of prostate cancers.

Combined evaluation of proliferation and apoptosis to calculate IC50 of VPA-induced PANC-1 cells and assessing its effect on the Wnt signaling pathway

Pancreatic ductal adenocarcinoma (PDAC) is among the most deadly cancers. Since most patients develop resistance to conventional treatments, new approaches are in urgency. Valproic acid (VPA) was shown to induce apoptosis and reduce proliferation in PANC-1 cells. Wnt signaling pathway is known to be involved in apoptosis and PDAC onset. However, VPA-induced apoptosis and its impact on Wnt signaling in PDACs are not linked, yet. We aimed to calculate IC₅₀ of VPA-induced PANC-1 cells by combined analyses of proliferation and apoptosis, while assessing its effect on Wnt signaling pathway. PANC-1 was induced with increased VPA doses and time points. Three independent proliferation and apoptosis assays were performed utilizing carboxyfluorescein succinimidyl ester and Annexin V/PI staining, respectively. Flow cytometry measurements were analyzed by CellQuest and NovoExpress. Taqman hydrolysis probes and SYBR Green PCR Mastermix were assessed in expression analyses of Wnt components utilizing 2^-ΔΔCt method. Cell proliferation was inhibited by 50% at 2.5 mM VPA that evoked a significant apoptotic response. Among the screened Wnt components and target genes, only LEF1 exhibited significant four-fold upregulation at this concentration. In conclusion, cancer studies mostly utilize MTT or BrdU assays in estimating cell proliferation and calculating IC₅₀ of drugs, which provided conflicting VPA dosages utilizing PANC-1 cells. Our novel combined approach enabled specific, accurate and reproducible IC₅₀ calculation at single cell basis with no apparent effect on Wnt signaling components. Future studies are needed to clarify the role of LEF1 in this model.

Synergistic Antitumor Activity of SH003 and Docetaxel via EGFR Signaling Inhibition in Non-Small Cell Lung Cancer

Epidermal growth factor receptor (EGFR) is overexpressed in lung cancer patients. Despite treatment with various EGFR tyrosine kinase inhibitors, recurrence and metastasis of lung cancer are inevitable. Docetaxel (DTX) is an effective conventional drug that is used to treat various cancers. Several researchers have studied the use of traditional herbal medicine in combination with docetaxel, to improve lung cancer treatment. SH003, a novel herbal mixture, exerts anticancer effects in different cancer cell types. Here, we aimed to investigate the apoptotic and anticancer effects of SH003 in combination with DTX, in human non-small-cell lung cancer (NSCLC). SH003, with DTX, induced apoptotic cell death, with increased expression of cleaved caspases and cleaved poly (ADP-ribose) polymerase in NSCLC cells. Moreover, SH003 and DTX induced the apoptosis of H460 cells via the suppression of the EGFR and signal transducer and activator of transcription 3 (STAT3) signaling pathways. In H460 tumor xenograft models, the administration of SH003 or docetaxel alone diminished tumor growth, and their combination effectively killed cancer cells, with increased expression of apoptotic markers and decreased expression of p-EGFR and p-STAT3. Collectively, the combination of SH003 and DTX may be a novel anticancer strategy to overcome the challenges that are associated with conventional lung cancer therapy.

Potential Therapies Targeting Metabolic Pathways in Cancer Stem Cells

Cancer stem cells (CSCs) are heterogeneous cells with stem cell-like properties that are responsible for therapeutic resistance, recurrence, and metastasis, and are the major cause for cancer treatment failure. Since CSCs have distinct metabolic characteristics that plays an important role in cancer development and progression, targeting metabolic pathways of CSCs appears to be a promising therapeutic approach for cancer treatment. Here we classify and discuss the unique metabolisms that CSCs rely on for energy production and survival, including mitochondrial respiration, glycolysis, glutaminolysis, and fatty acid metabolism. Because of metabolic plasticity, CSCs can switch between these metabolisms to acquire energy for tumor progression in different microenvironments compare to the rest of tumor bulk. Thus, we highlight the specific conditions and factors that promote or suppress CSCs properties to portray distinct metabolic phenotypes that attribute to CSCs in common cancers. Identification and characterization of the features in these metabolisms can offer new anticancer opportunities and improve the prognosis of cancer. However, the therapeutic window of metabolic inhibitors used alone or in combination may be rather narrow due to cytotoxicity to normal cells. In this review, we present current findings of potential targets in these four metabolic pathways for the development of more effective and alternative strategies to eradicate CSCs and treat cancer more effectively in the future.

Potential Therapies Targeting Metabolic Pathways in Cancer Stem Cells

Cancer stem cells (CSCs) are heterogeneous cells with stem cell-like properties that are responsible for therapeutic resistance, recurrence, and metastasis, and are the major cause for cancer treatment failure. Since CSCs have distinct metabolic characteristics that plays an important role in cancer development and progression, targeting metabolic pathways of CSCs appears to be a promising therapeutic approach for cancer treatment. Here we classify and discuss the unique metabolisms that CSCs rely on for energy production and survival, including mitochondrial respiration, glycolysis, glutaminolysis, and fatty acid metabolism. Because of metabolic plasticity, CSCs can switch between these metabolisms to acquire energy for tumor progression in different microenvironments compare to the rest of tumor bulk. Thus, we highlight the specific conditions and factors that promote or suppress CSCs properties to portray distinct metabolic phenotypes that attribute to CSCs in common cancers. Identification and characterization of the features in these metabolisms can offer new anticancer opportunities and improve the prognosis of cancer. However, the therapeutic window of metabolic inhibitors used alone or in combination may be rather narrow due to cytotoxicity to normal cells. In this review, we present current findings of potential targets in these four metabolic pathways for the development of more effective and alternative strategies to eradicate CSCs and treat cancer more effectively in the future.

Signal transducer and transcriptional activation 1 protects against pressure overload-induced cardiac hypertrophy

Signal transducers and transcriptional activation 1 (Stat1) is a member of the STATs family, and its role in various biological responses, including cell proliferation, differentiation, migration, apoptosis, and immune regulation has been extensively studied. We aimed to investigate its role in pathological cardiac hypertrophy, which is currently poorly understood. Experiments using H9C2 cardiomyocytes, Stat1, and IfngR cardiomyocyte-specific knockout mice revealed that Stat1 had a protective effect on cardiac hypertrophy. Using transverse aortic constriction (TAC)-induced cardiac hypertrophy in mice, we analyzed the degree of hypertrophy using echocardiography, pathology, and at the molecular level. Mice lacking Stat1 had more pronounced cardiac hypertrophy and fibrosis than wild-type TAC mice. Analysis of the molecular mechanisms suggested that Stat1 downregulated the mRNA levels of hypertrophy and fibrosis markers to inhibit cardiac hypertrophy, and promotes mitochondrial fission through the Ucp2/P-Drp1 pathway, enhancing mitochondrial function, and increasing compensatory myocardial ATP production in the compensatory phase for cardiac hypertrophy inhibition. Overall, this comprehensive analysis revealed that Stat1 inhibits cardiac hypertrophy by downregulating hypertrophic and fibrotic marker genes and enhancing the mitochondrial function to enhance cardiomyocyte function through the Ucp2/P-Drp1 signaling pathway.

Architecture of Cancer-Associated Fibroblasts in Tumor Microenvironment: Mapping Their Origins, Heterogeneity, and Role in Cancer Therapy Resistance

The tumor stroma, a key component of the tumor microenvironment (TME), is a key determinant of response and resistance to cancer treatment. The stromal cells, extracellular matrix (ECM), and blood vessels influence cancer cell response to therapy and play key roles in tumor relapse and therapeutic outcomes. Of the stromal cells present in the TME, much attention has been given to cancer-associated fibroblasts (CAFs) as they are the most abundant and important in cancer initiation, progression, and therapy resistance. Besides releasing several factors, CAFs also synthesize the ECM, a key component of the tumor stroma. In this expert review, we examine the role of CAFs in the regulation of tumor cell behavior and reveal how CAF-derived factors and signaling influence tumor cell heterogeneity and development of novel strategies to combat cancer. Importantly, CAFs display both phenotypic and functional heterogeneity, with significant ramifications on CAF-directed therapies. Principal anti-cancer therapies targeting CAFs take the form of: (1) CAFs' ablation through use of immunotherapies, (2) re-education of CAFs to normalize the cells, (3) cellular therapies involving CAFs delivering drugs such as oncolytic adenoviruses, and (4) stromal depletion via targeting the ECM and its related signaling. The CAFs' heterogeneity could be a result of different cellular origins and the cancer-specific tumor microenvironmental effects, underscoring the need for further multiomics and biochemical studies on CAFs and the subsets. Lastly, we present recent advances in therapeutic targeting of CAFs and the success of such endeavors or their lack thereof. We recommend that to advance global public health and personalized medicine, treatments in the oncology clinic should be combinatorial in nature, strategically targeting both cancer cells and stromal cells, and their interactions.

FGFR leads to sustained activation of STAT3 to mediate resistance to EGFR-TKIs treatment

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have led to great advances in the treatment of non-small cell lung cancer (NSCLC), but the emergence of drug resistance severely limits their clinical use. Thus, elucidation of the mechanism underlying resistance to EGFR-TKIs is of great importance. In our study, sustained activation of STAT3 was confirmed to be involved in resistance to EGFR-TKIs, and this resistance occurred regardless of exposure time, EGFR-TKIs type, and even cancer cell type. Mechanistically, the sustained activation of STAT3 was not related to gp130/JAK signalling pathway or HER2/EGFR heterodimer formation, while related to the expression and activation levels of STAT3. Furthermore, FGFR was shown to bind more strongly to STAT3 after gefitinib treatment, and the inhibition of FGFR reduced the phosphorylation of STAT3, thereby counteracting the effects of EGFR-TKIs and resulting in the synergistic inhibition of cancer cell proliferation. Taken together, the FGFR/STAT3 axis mediates the sustained activation of STAT3 upon EGFR-TKI treatment. This finding elucidates a new mechanism underlying drug resistance to EGFR-TKIs that the FGFR/STAT3 axis mediates the sustained activation of STAT3, providing theoretical support for considering the combination of TKIs and FGFR inhibitors in clinical cancer treatment.

Human-derived osteoblast-like cells and pericyte-like cells induce distinct metastatic phenotypes in primary breast cancer cells

Approximately 70% of advanced breast cancer patients will develop bone metastases, which accounts for ∼90% of cancer-related mortality. Breast cancer circulating tumor cells (CTCs) establish metastatic tumors in the bone after a close interaction with local bone marrow cells including pericytes and osteoblasts, both related to resident mesenchymal stem/stromal cells (BM-MSCs) progenitors. In vitro recapitulation of the critical cellular players of the bone microenvironment and infiltrating CTCs could provide new insights into their cross-talk during the metastatic cascade, helping in the development of novel therapeutic strategies. Human BM-MSCs were isolated and fractionated according to CD146 presence. CD146+ cells were utilized as pericyte-like cells (PLCs) given the high expression of the marker in perivascular cells, while CD146- cells were induced into an osteogenic phenotype generating osteoblast-like cells (OLCs). Transwell migration assays were performed to establish whether primary breast cancer cells (3384T) were attracted to OLC. Furthermore, proliferation of 3384T breast cancer cells was assessed in the presence of PLC- and OLC-derived conditioned media. Additionally, conditioned media cultures as well as transwell co-cultures of each OLCs and PLCs were performed with 3384T breast cancer cells for gene expression interrogation assessing their induced transcriptional changes with an emphasis on metastatic potential. PLC as well as their conditioned media increased motility and invasion potential of 3384T breast cancer cells, while OLC induced a dormant phenotype, downregulating invasiveness markers related with migration and proliferation. Altogether, these results indicate that PLC distinctively drive 3384T cancer cells to an invasive and migratory phenotype, while OLC induce a quiescence state, thus recapitulating the different phases of the in vivo bone metastatic process. These data show that phenotypic responses from metastasizing cancer cells are influenced by neighboring cells at the bone metastatic niche during the establishment of secondary metastatic tumors.

SENP1-mediated deSUMOylation of JAK2 regulates its kinase activity and platinum drug resistance

The JAK2/STAT pathway is hyperactivated in many cancers, and such hyperactivation is associated with a poor clinical prognosis and drug resistance. The mechanism regulating JAK2 activity is complex. Although translocation of JAK2 between nucleus and cytoplasm is an important regulatory mechanism, how JAK2 translocation is regulated and what is the physiological function of this translocation remain largely unknown. Here, we found that protease SENP1 directly interacts with and deSUMOylates JAK2, and the deSUMOylation of JAK2 leads to its accumulation at cytoplasm, where JAK2 is activated. Significantly, this novel SENP1/JAK2 axis is activated in platinum-resistant ovarian cancer in a manner dependent on a transcription factor RUNX2 and activated RUNX2/SENP1/JAK2 is critical for platinum-resistance in ovarian cancer. To explore the application of anti-SENP1/JAK2 for treatment of platinum-resistant ovarian cancer, we found SENP1 deficiency or treatment by SENP1 inhibitor Momordin Ic significantly overcomes platinum-resistance of ovarian cancer. Thus, this study not only identifies a novel mechanism regulating JAK2 activity, but also provides with a potential approach to treat platinum-resistant ovarian cancer by targeting SENP1/JAK2 pathway.

Cholangiocarcinoma: shedding light on the most promising drugs in clinical development

Introduction: Cholangiocarcinoma (CCA) is a diverse group of fatal malignancies arising from the biliary tract. Surgical resection with negative margin offers the only potentially curative option. The majority of patients present at locally advanced or metastatic stages, when surgical resection is not feasible, highlighting the significance of systemic therapy. Given the limited effectiveness of traditional chemotherapy regimens in CCA, many investigators have focused on developing novel molecular therapies targeting key aberrant signaling pathways.Areas covered: We present the main genomic aberrations known to play a key role in cholangiocarcinogenesis and discuss promising targeted therapies in clinical development.In October of 2020, a review of the English literature was performed utilizing PubMed and Web of Science databases for the keywords of 'cholangiocarcinoma', 'biliary tract cancer', and 'targeted therapy'.Expert opinion: Unfortunately, despite encouraging results in preclinical studies, the outcome of clinical trials with established targeted therapies like anti-EGFR medications have been discouraging. Currently, agents targeting FGFR2 fusion and IDH1/2 mutations hold great promise for improving the management of CCA. Future studies focused on enhancing our understanding of key aberrant signaling pathways of cholangiocarcinogenesis and the design of homogeneous and biomarker-driven cohorts are key elements of establishing precision medicine in CCA.

Current and Futuristic Roadmap of Ovarian Cancer Management: An Overview

Ovarian cancer (OC) is the most lethal gynecological malignancy among women worldwide. In most cases, it is diagnosed late at an advanced stage and does not respond well to existing therapies leading to its poor prognosis. In addition, other factors including epidemiological, complex histological diversity, multiple molecular alterations, and overlapping signaling pathways are also important contributors to poor disease outcome. Efforts have continued to develop a deeper understanding of the molecular pathogenesis and altered signaling nodes that provide hope for better clinical management through the development of novel approaches for early diagnosis, disease subtyping, prognosis, and therapy. In this chapter, we provide a detailed overview of OC and its histological subtypes and discuss prevalent molecular aberrations and active signaling pathways that drive OC progression. We also summarize various diagnostic and prognostic markers and therapeutic approaches currently being employed and discuss emerging findings that hold the potential to change the future course of OC management.

Phosphorylated transducer and activator of transcription-3 (pSTAT3) immunohistochemical expression in paired primary and metastatic colorectal cancer

BACKGROUND

Signal Transducer and Activator of Transcription-3 (STAT3) mediates cellular functions. We assessed the IHC expression of phosphorylated STAT3 (pSTAT3) in paired primary tumors and liver metastases in patients with advanced stage colorectal cancer (CRC).

METHODS

We included patients with tissue blocks available from both the primary CRC and a surgically resected liver metastasis. The IHC pSTAT3 expression agreement was measured using Cohen's kappa statistic.

RESULTS

The study included 103 patients, 55% male, median age was 64. 43% tumors originated in rectum, and 63% of the primary tumors were synchronous. Expression of pSTAT3 was 76% in liver metastases and 71% in primary tumors. A difference in pSTAT3 staining between the primary tumor and liver metastases was noted in 64%. There was lost expression of pSTAT3 in the liver metastases in 28% and gained expression in 36% of cases compared to the primary. The kappa statistic comparing agreement between staining patterns of the primary tumors and liver metastases was a "less-than-chance", at -0.02. Median survival was 4.9 years, with no difference in survival outcomes by pSTAT3 expression in the primary tumor or liver metastases.

DISCUSSION

STAT3 is not a prognostic marker in the selective setting of metastatic CRC to liver, but it may remain a potential therapeutic target given most liver metastases expressed pSTAT3. Discordant pSTAT3 expression in between primary tumors and paired liver metastases suggests that use of this class of drug to treat liver predominant metastatic colorectal cancer in a biomarker-driven approach may require confirmatory liver tumor biopsy.

Protein kinase 2 (CK2): a potential regulator of immune cell development and function in cancer

Protein kinase CK2, formally known as casein kinase II, is ubiquitously expressed and highly conserved serine/threonine or tyrosine kinase enzyme that regulates diverse signaling pathways responsible for cellular processes (i.e., cell proliferation and apoptosis) via interactions with over 500 known substrates. The enzyme's physiological interactions and cellular functions have been widely studied, most notably in the blood and solid malignancies. CK2 has intrinsic role in carcinogenesis as overexpression of CK2 subunits (α, α`, and β) and deregulation of its activity have been linked to various forms of cancers. CK2 also has extrinsic role in cancer stroma or in the tumor microenvironment (TME) including the immune cells. However, very few research studies have focused on extrinsic role of CK2 in regulating immune responses as a therapeutic alternative for cancer. The following review discusses CK2's regulation of key signaling events [Nuclear factor kappa B (NF-κB), Janus kinase/signal transducer and activators of transcription (JAK/STAT), Hypoxia inducible factor-1alpha (HIF-1α), Cyclooygenase-2 (COX-2), Extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK), Notch, Protein kinase B/AKT, Ikaros and Wnt] that can influence the development and function of immune cells in cancer. Potential clinical trials using potent CK2 inhibitors will facilitate and improve the treatment of human malignancies.

Targeting the JAK2/STAT3 Pathway-Can We Compare It to the Two Faces of the God Janus?

Muscle cachexia is one of the most critical unmet medical needs. Identifying the molecular background of cancer-induced muscle loss revealed a promising possibility of new therapeutic targets and new drug development. In this review, we will define the signal transducer and activator of transcription 3 (STAT3) protein's role in the tumor formation process and summarize the role of STAT3 in skeletal muscle cachexia. Finally, we will discuss a vast therapeutic potential for the STAT3-inhibiting single-agent treatment innovation that, as the desired outcome, could block tumor growth and generally prevent muscle cachexia.