Bavachin induces the apoptosis of multiple myeloma cell lines by inhibiting the activation of nuclear factor kappa B and signal transducer and activator of transcription 3

In Vitro Anti-Rotaviral Activity of Bavachin Isolated from Psoralea corylifolia L. (Fabaceae)

Rotavirus is the main causative agent of viral gastroenteritis among young animals worldwide. Currently, no clinically approved or effective antiviral drugs are available to combat rotavirus infections. Herein, we evaluated the anti-rotaviral activities of extracts and bavachin isolated from Psoralea corylifolia L. (Fabaceae) (P. corylifolia) against the bovine rotavirus G8P[7] and porcine rotavirus G5P[7] in vitro. Two assay strategies were performed: (1) a virucidal assay to reduce viral infectivity by virus neutralization and (2) a post-treatment assay to assess viral replication suppression. The results from the virucidal assay showed that the extracts and bavachin did not exert anti-rotaviral activities. In the follow-up analysis after treatment, bavachin exhibited robust antiviral efficacy, with 50% effective concentration (EC50) values of 10.6 μM (selectivity index [SI] = 2.38) against bovine rotavirus G8P[7] and 13.0 μM (SI = 1.94) against porcine rotavirus G5P[7]. Bavachin strongly suppressed viral RNA synthesis in the early (6 h) and late stages (18 h) after rotaviral infection. These findings strongly suggest that bavachin may have hindered the virions by effectively inhibiting the early stages of the virus replication cycle after rotaviral infection. Furthermore, confocal imaging showed that bavachin suppressed viral protein synthesis, notably that of the rotaviral protein (VP6). These results suggest that bavachin has strong antiviral activity against rotaviruses, inhibits viral replication, and is a candidate natural therapeutic drug targeting rotaviral infection. The utilization of bavachin isolated from P. corylifolia may contribute to decreased mortality rates, lower medication expenses, and enhanced economic viability in domestic farms.

A Scd1-mediated metabolic alteration participates in liver responses to low-dose bavachin

Hepatotoxicity induced by bioactive constituents in traditional Chinese medicines or herbs, such as bavachin (BV) in Fructus Psoraleae, has a prolonged latency to overt drug-induced liver injury in the clinic. Several studies have described BV-induced liver damage and underlying toxicity mechanisms, but little attention has been paid to the deciphering of organisms or cellular responses to BV at no-observed-adverse-effect level, and the underlying molecular mechanisms and specific indicators are also lacking during the asymptomatic phase, making it much harder for early recognition of hepatotoxicity. Here, we treated mice with BV for 7 days and did not detect any abnormalities in biochemical tests, but found subtle steatosis in BV-treated hepatocytes. We then profiled the gene expression of hepatocytes and non-parenchymal cells at single-cell resolution and discovered three types of hepatocyte subsets in the BV-treated liver. Among these, the hepa3 subtype suffered from a vast alteration in lipid metabolism, which was characterized by enhanced expression of apolipoproteins, carboxylesterases, and stearoyl-CoA desaturase 1 (Scd1). In particular, increased Scd1 promoted monounsaturated fatty acids (MUFAs) synthesis and was considered to be related to BV-induced steatosis and polyunsaturated fatty acids (PUFAs) generation, which participates in the initiation of ferroptosis. Additionally, we demonstrated that multiple intrinsic transcription factors, including Srebf1 and Hnf4a, and extrinsic signals from niche cells may regulate the above-mentioned molecular events in BV-treated hepatocytes. Collectively, our study deciphered the features of hepatocytes in response to BV insult, decoded the underlying molecular mechanisms, and suggested that Scd1 could be a hub molecule for the prediction of hepatotoxicity at an early stage.

Role of NF-κB Signaling in the Interplay between Multiple Myeloma and Mesenchymal Stromal Cells

Nuclear factor-κB (NF-κB) transcription factors play a key role in the pathogenesis of multiple myeloma (MM). The survival, proliferation and chemoresistance of malignant plasma cells largely rely on the activation of canonical and noncanonical NF-κB pathways. They are triggered by cancer-associated mutations or by the autocrine and paracrine production of cytokines and growth factors as well as direct interaction with cellular and noncellular components of bone marrow microenvironment (BM). In this context, NF-κB also significantly affects the activity of noncancerous cells, including mesenchymal stromal cells (MSCs), which have a critical role in disease progression. Indeed, NF-κB transcription factors are involved in inflammatory signaling that alters the functional properties of these cells to support cancer evolution. Moreover, they act as regulators and/or effectors of pathways involved in the interplay between MSCs and MM cells. The aim of this review is to analyze the role of NF-κB in this hematologic cancer, focusing on NF-κB-dependent mechanisms in tumor cells, MSCs and myeloma-mesenchymal stromal cell crosstalk.

Bavachin induces apoptosis in colorectal cancer cells through Gadd45a via the MAPK signaling pathway

Bavachin is a dihydroflavonoid compound isolated from Psoralea corylifolia, and exhibits anti-bacterial, anti-inflammatory, anti-tumor and lipid-lowering activities. Recent attention has gradually drawn on bavachin-induced apoptosis in many human cancer cell lines. However, the anti-cancer effects and related mechanisms in colorectal cancer remain unknown. Here, we investigated the effects of bavachin on colorectal cancer in vivo and in vitro. The results showed that bavachin inhibited the proliferation of human colorectal cancer cells and induce apoptosis. These changes were mediated by activating the MAPK signaling pathway, which significantly up-regulated the expression of Gadd45a. Furthermore, Gadd45a silencing obviously attenuated bavachin-mediated cell apoptosis. Inhibition of the MAPK signaling pathway by JNK/ERK/p38 inhibitors also weakened the up-regulation of Gadd45a by bavachin. The anticancer effect of bavachin was also validated using a mouse xenograft model of human colorectal cancer. In conclusion, these findings suggest that bavachin induces the apoptosis of colorectal cancer cells through activating the MAPK signaling pathway.

The Role of Natural Products as Inhibitors of JAK/STAT Signaling Pathways in Glioblastoma Treatment

The permeability of glioblastoma, as well as its escaping the immune system, makes them one of the most deadly human malignancies. By avoiding programmed cell death (apoptosis), unlimited cell growth and metastatic ability could dramatically affect the immune system. Genetic mutations, epigenetic changes, and overexpression of oncogenes can cause this process. On the other hand, the blood-brain barrier (BBB) and intratumor heterogeneity are important factors causing resistance to therapy. Several signaling pathways have been identified in this field, including the Janus tyrosine kinase (JAK) converter and signal transducer and activator of transcription (STAT) activator pathways, which are closely related. In addition, the JAK/STAT signaling pathway contributes to a wide array of tumorigenesis functions, including replication, anti-apoptosis, angiogenesis, and immune suppression. Introducing this pathway as the main tumorigenesis and treatment resistance center can give a better understanding of how it operates. In light of this, it is an important goal in treating many disorders, particularly cancer. The inhibition of this signaling pathway is being considered an approach to the treatment of glioblastoma. The use of natural products alternatively to conventional therapies is another area of research interest among researchers. Some natural products that originate from plants or natural sources can interfere with JAK/STAT signaling in human malignant cells, also by stopping the progression and phosphorylation of JAK/STAT, inducing apoptosis, and stopping the cell cycle. Natural products are a viable alternative to conventional chemotherapy because of their cost-effectiveness, wide availability, and almost no side effects.

Investigation of the effect of yarrow (Achillea millefolium) on Ehrlich ascites tumor

Introduction

One of the most important health problems today is cancer. The aim of this study was to investigate the in vitro effect of yarrow (Y) with known anticarcinogenic effect on Ehrlich ascites tumor (EAT).

Materials and Methods

The above-ground part (300 g) of Y was macerated with water and extracted three times for 24 hours at 37°C in a shaking water bath. In the study, EAT cells were divided into control, DMSO group 5-FU, 50, 100, 200, 400 and 800 μg/ml YP groups.

Results

At the end of the hour, it was observed that total apoptosis increased significantly in Y groups (especially 50 μg/ml) compared to the control group (p<0.05). It was observed that Y slowed the division of EAT cells (especially 800 μg/ml) by stopping the cell cycle at the G0/G1 stage. It was concluded that Y (especially at high doses) triggered apoptosis by significantly increasing the percentage of total depolarized cells (p<0.001) in all three time periods.

Conclusions

The results obtained showed that Y extract may have an antitumoral effect on EAT cells. It is thought that this study will contribute to studies on cancer treatment.

Evaluation of antitumoral effect of mistletoe fruit extract on Ehrlich ascites tumor cells with muse cell analyzer and argyrophilic nucleolar organizer region staining method

Introduction

Mistletoe has been used alone or as a complementary therapy in the treatment of different diseases for years. In this study, the antitumoral effect of mistletoe fruit extract on Ehrlich ascites tumor (EAT) cells was evaluated.

Materials and Methods

EAT cells from preformed stock mice were transferred to culture dishes containing 5-fluorouracil (5-FU) and mistletoe extracts at different doses (100, 200, 400, and 800 μg/ml). These cells were incubated at 37 °C in an environment with 95% humidity and 5% CO2. At the end of the incubations, the apoptosis status of the cells, cell cycle, mitochondrial membrane potential, and proliferation status with the argyrophilic (Ag) nucleolar organizer region staining (NORs) method were evaluated.

Results

As a result, it was observed that the mistletoe fruit extract and 5-FU induce apoptosis of EAT cells. It was concluded that the 5-FU substance arrests the cell cycle at the G0/G1 stage, while the mistletoe arrests the cell cycle at the S and G2/M stages. The depolarization rate of the mistletoe treated cells was higher. As a result of the evaluation made with the AgNORs method, it was seen that mistletoe and 5-FU could be effective in reducing the proliferation of EAT cells.

Conclusions

It was seen that mistletoe fruit extract could be effective in stimulating the apoptosis and depolarization of cancer cells. The results of other studies in the literature and our study support each other. It was concluded that the mistletoe plant may be useful in cancer treatment.

Bavachin produces immunoadjuvant activity by targeting the NFAT signaling pathway

BACKGROUND

Bavachin, a flavonoid compound isolated from the seeds and fruits of Psoralea corylifolia l. (family Fabaceae), is used as a traditional medicine in Asia. Indeed, it is reported to have various medicinal functions such as estrogenic and antiinflammatory activities among others. However, to date, the effects of bavachin on T cell activation have yet to be reported.

PURPOSE AND STUDY DESIGN

We aimed to determine the effects of bavachin on the activation of a human T cell line in vitro and on antigen-specific immune responses in mice in vivo.

METHODS

In a nuclear factor of activated T cells (NFAT) activity assay, the Jurkat T cell line expressing a luciferase reporter driven by an NFAT-response element was stimulated with antihuman CD3/CD28 antibody and bavachin. Furthermore, the level of cytokine production was measured in the Jurkat T cell line stimulated with phorbol 12-myristate 13-acetate/ionomycin and bavachin using an IL-2 ELISA and a cytometric bead array assay. For in vivo analyses, mice were subcutaneously immunized with an antigen (ovalbumin protein) and bavachin, and the immune responses of mice were analyzed by FACS analysis, a T cell proliferation assay, a cytokine ELISA, and an antiovalbumin-specific antibody ELISA.

RESULTS

We found that bavachin activated NFAT-mediated transcription in the human T cell line in vitro. In mice, when bavachin was administered with the antigen, an increase in T cell responses and antibody production specific to the antigen was observed.

CONCLUSION

Our results suggest that bavachin has immunoadjuvant and immunomodulation effects, which arise through activation of the NFAT signaling pathway.

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

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

Pharmacological Effects of Polyphenol Phytochemicals on the JAK-STAT Signaling Pathway

The JAK-STAT signaling pathway is a common pathway of many cytokine signal transductions, closely related to cell proliferation, apoptosis, differentiation, and inflammatory response. It is essential for inhibiting the inflammatory response, initiating innate immunity, and coordinating adaptive immune mechanisms. Owing to the nature of this pathway and its potential cross-epitopes with multiple alternative pathways, the long-term efficacy of monotherapy-based adaptive targeting therapy is limited, and the majority of drugs targeting STATs are still in the preclinical phase. Meanwhile, curcumin, quercetin, and several kinds of plant polyphenol chemicals play roles in multiple sites of the JAK-STAT pathway to suppress abnormal activation. Polyphenol compounds have shown remarkable effects by acting on the JAK-STAT pathway in anti-inflammatory, antitumor, and cardiovascular disease control. This review summarizes the pharmacological effects of more than 20 kinds of phytochemicals on JAK-STAT signaling pathway according to the chemical structure of polyphenolic phytochemicals.

Bavachin exerted anti-neuroinflammatory effects by regulation of A20 ubiquitin-editing complex

Neuroinflammation is a major pathophysiological contributor to the progression of the central nervous system disorders. Bavachin is a natural product belonging to the flavonoid class. The anti-neuroinflammatory effect and the molecular mechanisms are not well understood. In this study, we found bavachin can exert anti-neuroinflammatory effect via inhibition of nuclear factor-kappa B (NF-κB) signaling. We found that bavachin can obviously upregulate the expression of A20 (TNFAIP3) in microglial cells. Further studies suggested siRNA-A20 knockdown treatment can attenuate the inhibitory effects of bavachin on neuroinflammation. We further found bavachin can increase the interaction of ubiquitin-editing enzyme A20 complex including A20, Tax1-binding protein 1 (TAX1BP1) and Itch, the subsequently downregulated the K63-ubiquitination of TNF receptor associated factor 6 (TRAF6) and NF-κB signaling pathway. Altogether, our results indicated that bavachin exerted anti-neuroinflammatory effects through inhibition of NF-κB signaling mediated by regulation of ubiquitin-editing enzyme A20 complex. Our finding has important clinical significance for the potential application of bavachin in the treatment of neurological disorders.

Activation of Serum/Glucocorticoid Regulated Kinase 1/Nuclear Factor-κB Pathway Are Correlated with Low Sensitivity to Bortezomib and Ixazomib in Resistant Multiple Myeloma Cells

Multiple myeloma (MM) is an incurable malignancy often associated with primary and acquired resistance to therapeutic agents, such as proteasome inhibitors. However, the mechanisms underlying the proteasome inhibitor resistance are poorly understood. Here, we elucidate the mechanism of primary resistance to bortezomib and ixazomib in the MM cell lines, KMS-20, KMS-26, and KMS-28BM. We find that low bortezomib and ixazomib concentrations induce cell death in KMS-26 and KMS-28BM cells. However, high bortezomib and ixazomib concentrations induce cell death only in KMS-20 cells. During Gene Expression Omnibus analysis, KMS-20 cells exhibit high levels of expression of various genes, including anti-phospho-fibroblast growth factor receptor 1 (FGFR1), chemokine receptor type (CCR2), and serum and glucocorticoid regulated kinase (SGK)1. The SGK1 inhibitor enhances the cytotoxic effects of bortezomib and ixazomib; however, FGFR1 and CCR2 inhibitors do not show such effect in KMS-20 cells. Moreover, SGK1 activation induces the phosphorylation of NF-κB p65, and an NF-κB inhibitor enhances the sensitivity of KMS-20 cells to bortezomib and ixazomib. Additionally, high levels of expression of SGK1 and NF-κB p65 is associated with a low sensitivity to bortezomib and a poor prognosis in MM patients. These results indicate that the activation of the SGK1/NF-κB pathway correlates with a low sensitivity to bortezomib and ixazomib, and a combination of bortezomib and ixazomib with an SGK1 or NF-κB inhibitor may be involved in the treatment of MM via activation of the SGK1/NF-κB pathway.

Targeting X chromosome-linked inhibitor of apoptosis protein in mucoepidermoid carcinoma of the head and neck: A novel therapeutic strategy using nitidine chloride

Nitidine chloride (NC) was recently reported to exhibit a wide range of pharmacological properties for several diseases, including cancer. Here we report for the first time that NC is a potential therapeutic agent for mucoepidermoid carcinoma (MEC) occurring in the head and neck because it suppresses X chromosome-linked inhibitor of apoptosis protein (XIAP) in human MEC in vitro and in vivo. The antitumor effects of NC were evaluated by trypan blue exclusion assay, western blotting, live/dead assay, 4',6-diamidino-2-phenylindole (DAPI) staining, human apoptosis antibody array, immunofluorescence staining, immunohistochemistry, small interfering RNA assay, transient transfection of XIAP overexpression vector, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and histopathological examination of organs. NC inhibited cell viability and induced caspase-dependent apoptosis in vitro. A human apoptosis antibody array assay showed that XIAP is suppressed by NC treatment. XIAP was overexpressed in oral squamous cell carcinoma (OSCC) tissues that arose from the head and neck, and high XIAP expression was correlated with poor prognosis in OSCC patients. XIAP depletion significantly increased apoptosis, and ectopic XIAP overexpression attenuated the apoptosis induced by NC treatment. NC suppressed tumor growth in vivo at a dosage of 5 mg/kg/day. The number of TUNEL-positive cells increased and the protein expression of XIAP was consistently downregulated in NC-treated tumor tissues. In addition, NC caused no histopathological changes in the liver or kidney. These findings provide new insights into the mechanism of action underlying the anticancer effects of NC and demonstrate that NC is a promising therapeutic agent for the treatment of human MEC of the head and neck. KEY MESSAGES: • Nitidine chloride induces caspase-dependent apoptosis in MEC of the head and neck. • High XIAP expression correlates with poor prognosis of OSCC patients. • Nitidine chloride suppresses tumor growth in vivo without any systemic toxicities. • Targeting XIAP is a novel chemotherapeutic strategy for MEC of the head and neck.

Bavachin suppresses human placental choriocarcinoma cells by targeting electron transport chain complexes and mitochondrial dysfunction

Phytoestrogens are naturally derived estrogen-like therapeutic compounds that have long been studied for their role as anti-cancer agents and supplements during chemotherapy. Bavachin is a therapeutic phytoestrogen used to treat cancer, inflammation, and diabetes mellitus. Though the therapeutic effects of bavachin on various diseases have been explored, its anti-cancer effects and related mechanisms in human placental choriocarcinoma remain unknown. This is the first study to identify the anti-cancer potential of bavachin on human placental choriocarcinoma cell lines JEG3 and JAR. Placental mitochondria support the elevated energy production required for placental development, through oxidative phosphorylation (OXPHOS). Based on this concept, we hypothesized that mitochondrial targeting by bavachin may contribute to anti-cancer activities in high-OXPHOS subtypes of cancer such as placental choriocarcinoma. Apoptosis and caspase activities were increased by bavachin in placental choriocarcinoma cells. Bavachin altered metabolic phenotypes by regulating electron transport chain complex and OXPHOS to suppress choriocarcinoma cell proliferation. It also led to calcium disruption and endoplasmic reticulum stress accompanied by mitochondrial membrane potential depolarization. It showed synergistic anti-cancer effects with paclitaxel on placental choriocarcinoma cells. Taken together, we suggest that bavachin has therapeutic potential against placental choriocarcinoma and may be used to counter paclitaxel-induced toxicity.

Targeting the JAK/STAT Signaling Pathway Using Phytocompounds for Cancer Prevention and Therapy

Cancer is a prevalent cause of mortality around the world. Aberrated activation of Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway promotes tumorigenesis. Natural agents, including phytochemicals, exhibit potent anticancer activities via various mechanisms. However, the therapeutic potency of phytoconstituents as inhibitors of JAK/STAT signaling against cancer has only come into focus in recent days. The current review highlights phytochemicals that can suppress the JAK/STAT pathway in order to impede cancer cell growth. Various databases, such as PubMed, ScienceDirect, Web of Science, SpringerLink, Scopus, and Google Scholar, were searched using relevant keywords. Once the authors were in agreement regarding the suitability of a study, a full-length form of the relevant article was obtained, and the information was gathered and cited. All the complete articles that were incorporated after the literature collection rejection criteria were applied were perused in-depth and material was extracted based on the importance, relevance, and advancement of the apprehending of the JAK/STAT pathway and their relation to phytochemicals. Based on the critical and comprehensive analysis of literature presented in this review, phytochemicals from diverse plant origins exert therapeutic and cancer preventive effects, at least in part, through regulation of the JAK/STAT pathway. Nevertheless, more preclinical and clinical research is necessary to completely comprehend the capability of modulating JAK/STAT signaling to achieve efficient cancer control and treatment.

Bavachin Protects Human Aortic Smooth Muscle Cells Against β-Glycerophosphate-Mediated Vascular Calcification and Apoptosis via Activation of mTOR-Dependent Autophagy and Suppression of β-Catenin Signaling

Vascular calcification is a major complication of cardiovascular disease and chronic renal failure. Autophagy help to maintain a stable internal and external environment that is important for modulating arteriosclerosis, but its pathogenic mechanism is far from clear. Here, we aimed to identify the bioactive compounds from traditional Chinese medicines (TCM) that exhibit an anti-arteriosclerosis effect. In β-glycerophosphate (β-GP)-stimulated human aortic smooth muscle cells (HASMCs), the calcium level was increased and the expression of the calcification-related proteins OPG, OPN, Runx2, and BMP2 were all up-regulated, followed by autophagy induction and apoptosis. Meanwhile, we further revealed that β-GP induced apoptosis of human osteoblasts and promoted differentiation of osteoblasts through Wnt/β-catenin signaling. Bavachin, a natural compound from Psoralea corylifolia, dose-dependently reduced the level of intracellular calcium and the expression of calcification-related proteins OPG, OPN, Runx2 and BMP2, thus inhibiting cell apoptosis. In addition, bavachin increased LC3-II and beclin1 expression, along with intracellular LC3-II puncta formation, which autophagy induction is Atg7-dependent and is regulated by suppression of mTOR signaling. Furthermore, addition of autophagy inhibitor, wortmannin (WM) attenuated the inhibitory effect of bavachin on β-GP-induced calcification and apoptosis in HASMCs. Collectively, the present study revealed that bavachin protects HASMCs against apoptosis and calcification by activation of the Atg7/mTOR-autophagy pathway and suppression of the β-catenin signaling, our findings provide a potential clinical application for bavachin in the therapy of cardiovascular disease.

STAT3: A Promising Therapeutic Target in Multiple Myeloma

Multiple myeloma (MM) is an incurable plasma cell malignancy for which novel treatment options are required. Signal Transducer and Activator of Transcription 3 (STAT3) overexpression in MM appears to be mediated by a variety of factors including interleukin-6 signaling and downregulation of Src homology phosphatase-1 (SHP-1). STAT3 overexpression in MM is associated with an adverse prognosis and may play a role in microenvironment-dependent treatment resistance. In addition to its pro-proliferative role, STAT3 upregulates anti-apoptotic proteins and leads to microRNA dysregulation in MM. Phosphatase of regenerating liver 3 (PRL-3) is an oncogenic phosphatase which is upregulated by STAT3. PRL-3 itself promotes STAT-3 phosphorylation resulting in a positive feedback loop. PRL-3 is overexpressed in a subset of MM patients and may cooperate with STAT3 to promote survival of MM cells. Indirectly targeting STAT3 via JAK (janus associated kinase) inhibition has shown promise in early clinical trials. Specific inhibitors of STAT3 showed in vitro efficacy but have failed in clinical trials while several STAT3 inhibitors derived from herbs have been shown to induce apoptosis of MM cells in vitro. Optimising the pharmacokinetic profiles of novel STAT3 inhibitors and identifying how best to combine these agents with existing anti-myeloma therapy are key questions to be addressed in future clinical trials.

The Role of Signal Transducer and Activator of Transcription 3 (STAT3) and Its Targeted Inhibition in Hematological Malignancies

Signal transducer and activator of transcription 3 (STAT3), a member of the STAT protein family, can be phosphorylated by receptor-associated Janus kinases (JAKs) in response to stimulation by cytokines and growth factors. It forms homo- or heterodimers that can translocate to the cell nucleus where they act as transcription activators. Constitutive activation of STAT3 has been found to be associated with initiation and progression of various cancers. It can exert proliferative as well as anti-apoptotic effects. This review focuses on the role of STAT3 in pathogenesis i.e., proliferation, differentiation, migration, and apoptosis of hematological malignancies viz. leukemia, lymphoma and myeloma, and briefly highlights the potential therapeutic approaches developed against STAT3 activation pathway.