c-MYC functions as a molecular switch to alter the response of human mammary epithelial cells to oncostatin M

Human platelet lysate enhances in vivo activity of CAR-Vδ2 T cells by reducing cellular senescence and apoptosis

BACKGROUND AIMS

Vγ9Vδ2 T cells are an attractive cell platform for the off-the-shelf cancer immunotherapy as the result of their lack of alloreactivity and inherent multi-pronged cytotoxicity, which could be further amplified with chimeric antigen receptors (CARs). In this study, we sought to enhance the in vivo longevity of CAR-Vδ2 T cells by modulating ex vivo manufacturing conditions and selecting an optimal CAR costimulatory domain.

METHODS

Specifically, we compared the anti-tumor activity of Vδ2 T cells expressing anti-CD19 CARs with costimulatory endodomains derived from CD28, 4-1BB or CD27 and generated in either standard fetal bovine serum (FBS)- or human platelet lysate (HPL)-supplemented medium.

RESULTS

We found that HPL supported greater expansion of CAR-Vδ2 T cells with comparable in vitro cytotoxicity and cytokine secretion to FBS-expanded CAR-Vδ2 T cells. HPL-expanded CAR-Vδ2 T cells showed enhanced in vivo anti-tumor activity with longer T-cell persistence compared with FBS counterparts, with 4-1BB costimulated CAR showing the greatest activity. Mechanistically, HPL-expanded CAR Vδ2 T cells exhibited reduced apoptosis and senescence transcriptional pathways compared to FBS-expanded CAR-Vδ2 T cells and increased telomerase activity.

CONCLUSIONS

This study supports enhancement of therapeutic potency of CAR-Vδ2 T cells through a manufacturing improvement.

Identification of PIK3R5 as a hub in septic myocardial injury and the cardioprotective effects of Psoralidin

BACKGROUND

Myocardial injury is a severe complication of sepsis, resulting in substantial morbidity and mortality. Psoralidin (PSO), derived from the seeds of Psoralea corylifolia L., has garnered considerable attention due to its potent pharmacological effects, including anti-inflammatory and antibacterial effects.

PURPOSE

Our previous work conducted affirmed that PSO has a protective effect on sepsis and septic myocardial injury, however the specific molecular mechanisms need further clarification.

STUDY DESIGN

This objective of this study was to use three analytic modalities and bioinformatics methods to identify potential targets, followed by experimental verification.

METHODS

A series of experiments methods (including echocardiography, HE, western blot, qPCR, RNA-seq, network pharmacology) were used to evaluate the effects of PSO against sepsis and septic myocardial injury in cecal ligation and puncture (CLP)-injured BALB/c mice and lipopolysaccharide (LPS)-injured HL-1 cardiomyocytes.

RESULTS

Firstly, a group of sepsis-related genes were identified by integrating database surveys, RNA-seq analysis, and weighted gene co-expression network analysis (WCGNA). Subsequently, the pharmacological targets of PSO were predicted. Furthermore, the identification of phosphoinositide 3- kinase regulatory subunit 5 (PIK3R5) as a crucial hub gene was accomplished via protein-protein interaction network and molecular docking approach. In vivo experiments showed that PSO treatment alleviated septic myocardial injury, as evidenced by improved cardiac function indicators and inflammation response. Similar results were obtained in vitro experiments. Importantly, the expression of PI3KR5 was decreased in the myocardium and cardiomyocytes, and the effect was reversed by PSO treatment.

CONCLUSION

This study systematically revealed the key targets of PSO in the treatment of septic myocardial injury. These findings offer valuable insights into disease-drug targets, which have certain clinical significance to exploring disease biomarkers and potential therapeutic targets for septic patients.

The clinical relevance of OSM in inflammatory diseases: a comprehensive review

Oncostatin M (OSM) is a pleiotropic cytokine involved in a variety of inflammatory responses such as wound healing, liver regeneration, and bone remodeling. As a member of the interleukin-6 (IL-6) family of cytokines, OSM binds the shared receptor gp130, recruits either OSMRβ or LIFRβ, and activates a variety of signaling pathways including the JAK/STAT, MAPK, JNK, and PI3K/AKT pathways. Since its discovery in 1986, OSM has been identified as a significant contributor to a multitude of inflammatory diseases, including arthritis, inflammatory bowel disease, lung and skin disease, cardiovascular disease, and most recently, COVID-19. Additionally, OSM has also been extensively studied in the context of several cancer types including breast, cervical, ovarian, testicular, colon and gastrointestinal, brain,lung, skin, as well as other cancers. While OSM has been recognized as a significant contributor for each of these diseases, and studies have shown OSM inhibition is effective at treating or reducing symptoms, very few therapeutics have succeeded into clinical trials, and none have yet been approved by the FDA for treatment. In this review, we outline the role OSM plays in a variety of inflammatory diseases, including cancer, and outline the previous and current strategies for developing an inhibitor for OSM signaling.

c-MYC mediates the crosstalk between breast cancer cells and tumor microenvironment

The MYC oncogenic family is dysregulated in diverse tumors which is generally linked to the poor prognosis of tumors. The members in MYC family are transcription factors which are responsible for the regulation of various genes expression. Among them, c-MYC is closely related to the progression of tumors. Furthermore, c-MYC aberrations is tightly associated with the prevalence of breast cancer. Tumor microenvironment (TME) is composed of many different types of cellular and non-cellular factors, mainly including cancer-associated fibroblasts, tumor-associated macrophages, vascular endothelial cells, myeloid-derived suppressor cells and immune cells, all of which can affect the diagnosis, prognosis, and therapeutic efficacy of breast cancer. Importantly, the biological processes occurred in TME, such as angiogenesis, immune evasion, invasion, migration, and the recruition of stromal and tumor-infiltrating cells are under the modulation of c-MYC. These findings indicated that c-MYC serves as a critical regulator of TME. Here, we aimed to summarize and review the relevant research, thus to clarify c-MYC is a key mediator between breast cancer cells and TME. Video Abstract.

Activation of OSM-STAT3 Epigenetically Regulates Tumor-Promoting Transcriptional Programs in Cervical Cancer

Despite improvements in preventative strategies, such as regular screenings with Pap tests and human papillomavirus (HPV) tests as well as HPV vaccinations, effective treatment for advanced cervical cancer remains poor. Deregulation of STAT3 is an oncogenic factor that promotes tumorigenesis and epithelial-to-mesenchymal transition (EMT) in various cancers. Oncostatin M (OSM), a pleiotropic cytokine, induces STAT3 activation, exacerbating cervical cancer. However, the mechanism by which the OSM-STAT3 axis epigenetically regulates tumor-progression-related genes in cervical cancer is not well understood. Here, we show that OSM-mediated STAT3 activation promotes pro-tumorigenic gene expression programs, with chromatin remodeling in cervical cancer. Reanalysis of scRNA-seq data performed in cervical cancer uncovered an interaction between the oncostatin M receptor (OSMR) on tumor cells and OSM induced by tumor-associated macrophages (TAMs). Our gene expression profiling (bulk RNA-seq) shows that OSM-induced genes were involved in hypoxia, wound healing, and angiogenesis, which were significantly inhibited by SD-36, a STAT3-selective degrader. Additionally, ATAC-seq experiments revealed that STAT3 binding motifs were preferentially enriched in open chromatin regions of the OSM-STAT3-regulated genes. Among the 50 candidate genes that were regulated epigenetically through the OSM-STAT3 axis, we found that the expression levels of NDRG1, HK2, PLOD2, and NPC1 were significantly correlated with those of OSMR and STAT3 in three independent cervical cancer cohorts. Also, higher expression levels of these genes are significantly associated with poor prognosis in cervical cancer patients. Collectively, our findings demonstrate that the OSM-STAT3 signaling pathway regulates crucial transcriptomic programs through epigenetic changes and that selective inhibition of STAT3 may be a novel therapeutic strategy for patients with advanced cervical cancer.

Muscle-to-tumor crosstalk: The effect of exercise-induced myokine on cancer progression

Physical exercise has gradually become a focus in cancer treatment due to its pronounced role in reducing cancer risk, enhancing therapeutic efficacy, and improving prognosis. In recent decades, skeletal muscles have been considered endocrine organs, exerting their biological functions via the endocrine, autocrine, and paracrine systems by secreting various types of myokines. The amount of myokines secreted varies depending on the intensity, type, and duration of exercise. Recent studies have shown that muscle-derived myokines are highly involved the effects of exercise on cancer. Multiple myokines, such as interleukin-6 (IL-6), oncostatin M (OSM), secreted protein acidic and rich in cysteine (SPARC), and irisin, directly mediate cancer progression by influencing the proliferation, apoptosis, stemness, drug resistance, metabolic reprogramming, and epithelial-mesenchymal transformation (EMT) of cancer cells. In addition, IL-6, interleukin-8 (IL-8), interleukin-15 (IL-15), brain-derived neurotrophic factor (BDNF), and irisin can improve obesity-induced inflammation by stimulating lipolysis of adipose tissues, promoting glucose uptake, and accelerating the browning of white fat. Furthermore, some myokines could regulate the tumor microenvironment, such as angiogenesis and the immune microenvironment. Cancer cachexia occurs in up to 80% of cancer patients and is responsible for 22%-30% of patient deaths. It is characterized by systemic inflammation and decreased muscle mass. Exercise-induced myokine production is important in regulating cancer cachexia. This review summarizes the roles and underlying mechanisms of myokines, such as IL-6, myostatin, IL-15, irisin, fibroblast growth factor 21 (FGF21) and musclin, in cancer cachexia. Through comprehensive analysis, we conclude that myokines are potential targets for inhibiting cancer progression and the associated cachexia.

Stromal oncostatin M cytokine promotes breast cancer progression by reprogramming the tumor microenvironment

The tumor microenvironment (TME) is reprogrammed by cancer cells and participates in all stages of tumor progression. The contribution of stromal cells to the reprogramming of the TME is not well understood. Here, we provide evidence of the role of the cytokine oncostatin M (OSM) as central node for multicellular interactions between immune and nonimmune stromal cells and the epithelial cancer cell compartment. OSM receptor (OSMR) deletion in a multistage breast cancer model halted tumor progression. We ascribed causality to the stromal function of the OSM axis by demonstrating reduced tumor burden of syngeneic tumors implanted in mice lacking OSMR. Single-cell and bioinformatic analysis of murine and human breast tumors revealed that OSM expression was restricted to myeloid cells, whereas OSMR was detected predominantly in fibroblasts and, to a lower extent, cancer cells. Myeloid-derived OSM reprogrammed fibroblasts to a more contractile and tumorigenic phenotype and elicited the secretion of VEGF and proinflammatory chemokines CXCL1 and CXCL16, leading to increased myeloid cell recruitment. Collectively, our data support the notion that the stromal OSM/OSMR axis reprograms the immune and nonimmune microenvironment and plays a key role in breast cancer progression.

The Role of the IL-6 Cytokine Family in Epithelial-Mesenchymal Plasticity in Cancer Progression

Epithelial–mesenchymal plasticity (EMP) plays critical roles during embryonic development, wound repair, fibrosis, inflammation and cancer. During cancer progression, EMP results in heterogeneous and dynamic populations of cells with mixed epithelial and mesenchymal characteristics, which are required for local invasion and metastatic dissemination. Cancer development is associated with an inflammatory microenvironment characterized by the accumulation of multiple immune cells and pro-inflammatory mediators, such as cytokines and chemokines. Cytokines from the interleukin 6 (IL-6) family play fundamental roles in mediating tumour-promoting inflammation within the tumour microenvironment, and have been associated with chronic inflammation, autoimmunity, infectious diseases and cancer, where some members often act as diagnostic or prognostic biomarkers. All IL-6 family members signal through the Janus kinase (JAK)–signal transducer and activator of transcription (STAT) pathway and are able to activate a wide array of signalling pathways and transcription factors. In general, IL-6 cytokines activate EMP processes, fostering the acquisition of mesenchymal features in cancer cells. However, this effect may be highly context dependent. This review will summarise all the relevant literature related to all members of the IL-6 family and EMP, although it is mainly focused on IL-6 and oncostatin M (OSM), the family members that have been more extensively studied.

Emerging Perspectives on Leukemia Inhibitory Factor and its Receptor in Cancer

Tumorigenesis and metastasis have deep connections to inflammation and inflammatory cytokines, but the mechanisms underlying these relationships are poorly understood. Leukemia Inhibitory Factor (LIF) and its receptor (LIFR), part of the interleukin-6 (IL-6) cytokine family, make up one such ill-defined piece of the puzzle connecting inflammation to cancer. Although other members of the IL-6 family have been shown to be involved in the metastasis of multiple types of cancer, the role of LIF and LIFR has been challenging to determine. Described by others in the past as enigmatic and paradoxical, LIF and LIFR are expressed in a diverse array of cells in the body, and the narrative surrounding them in cancer-related processes has been vague, and at times even contradictory. Despite this, recent insights into their functional roles in cancer have highlighted interesting patterns that may allude to a broader understanding of LIF and LIFR within tumor growth and metastasis. This review will discuss in depth the signaling pathways activated by LIF and LIFR specifically in the context of cancer–the purpose being to summarize recent literature concerning the downstream effects of LIF/LIFR signaling in a variety of cancer-related circumstances in an effort to begin teasing out the intricate web of contradictions that have made this pair so challenging to define.

Aberrant Induction of a Mesenchymal/Stem Cell Program Engages Senescence in Normal Mammary Epithelial Cells

Although frequently associated with tumor progression, inflammatory cytokines initially restrain transformation by inducing senescence, a key tumor-suppressive barrier. Here, we demonstrate that the inflammatory cytokine, oncostatin M, activates a mesenchymal/stem cell (SC) program that engages cytokine-induced senescence (CIS) in normal human epithelial cells. CIS is driven by Snail induction and requires cooperation between STAT3 and the TGFβ effector, SMAD3. Importantly, as cells escape CIS, they retain the mesenchymal/SC program and are thereby bestowed with a set of cancer SC (CSC) traits. Of therapeutic importance, cells that escape CIS can be induced back into senescence by CDK4/6 inhibition, confirming that the mechanisms allowing cells to escape senescence are targetable and reversible. Moreover, by combining CDK4/6 inhibition with a senolytic therapy, mesenchymal/CSCs can be efficiently killed. Our studies provide insight into how the CIS barriers that prevent tumorigenesis can be exploited as potential therapies for highly aggressive cancers. IMPLICATIONS: These studies reveal how a normal cell's arduous escape from senescence can bestow aggressive features early in the transformation process, and how this persistent mesenchymal/SC program can create a novel potential targetability following tumor development.

Oncostatin M: A mysterious cytokine in cancers

Oncostatin M (OSM), as a member of the Interleukin-6 family cytokines, plays a significant role in inflammation, autoimmunity, and cancers. It is mainly secreted by T lymphocytes, neutrophils, and macrophages and was initially introduced as anti-cancer agent. However, in some cases, it promotes cancer progression. Overexpression of OSM and OSM receptor has been detected in various cancers including colon cancer, breast cancer, pancreatic cancer, myeloma, brain tumors, chronic lymphocytic leukemia, and hepatoblastoma. STAT3 is the main downstream signaling molecule of OSM, which operates the leading role in modifications of cancer cells and enhancing cell growth, invasion, survival, and all other hallmarks of cancer cells. However, due to the presence of multiple signaling pathways, it can act contradictory in some cancers. In this review, we will discuss the emerging roles of OSM in cancer and elucidate its function in tumor control or progression and finally discuss therapeutic approaches designed to manipulate this cytokine in cancer.

OSMR controls glioma stem cell respiration and confers resistance of glioblastoma to ionizing radiation

Glioblastoma contains a rare population of self-renewing brain tumor stem cells (BTSCs) which are endowed with properties to proliferate, spur the growth of new tumors, and at the same time, evade ionizing radiation (IR) and chemotherapy. However, the drivers of BTSC resistance to therapy remain unknown. The cytokine receptor for oncostatin M (OSMR) regulates BTSC proliferation and glioblastoma tumorigenesis. Here, we report our discovery of a mitochondrial OSMR that confers resistance to IR via regulation of oxidative phosphorylation, independent of its role in cell proliferation. Mechanistically, OSMR is targeted to the mitochondrial matrix via the presequence translocase-associated motor complex components, mtHSP70 and TIM44. OSMR interacts with NADH ubiquinone oxidoreductase 1/2 (NDUFS1/2) of complex I and promotes mitochondrial respiration. Deletion of OSMR impairs spare respiratory capacity, increases reactive oxygen species, and sensitizes BTSCs to IR-induced cell death. Importantly, suppression of OSMR improves glioblastoma response to IR and prolongs lifespan.

The suppression of the receptor for oncostatin M (OSMR) can prevent glioblastoma cell growth. Here, the authors demonstrate a role for OSMR in modulating glioma stem cell respiration and its impact on resistance to ionizing radiation.

A FAM83A Positive Feed-back Loop Drives Survival and Tumorigenicity of Pancreatic Ductal Adenocarcinomas

Pancreatic ductal adenocarcinomas (PDAC) are deadly on account of the delay in diagnosis and dearth of effective treatment options for advanced disease. The insurmountable hurdle of targeting oncogene KRAS, the most prevalent genetic mutation in PDAC, has delayed the availability of targeted therapy for PDAC patients. An alternate approach is to target other tumour-exclusive effector proteins important in RAS signalling. The Family with Sequence Similarity 83 (FAM83) proteins are oncogenic, tumour-exclusive and function similarly to RAS, by driving the activation of PI3K and MAPK signalling. In this study we show that FAM83A expression is significantly elevated in human and murine pancreatic cancers and is essential for the growth and tumorigenesis of pancreatic cancer cells. Elevated FAM83A expression maintains essential MEK/ERK survival signalling, preventing cell death in pancreatic cancer cells. Moreover, we identified a positive feed-forward loop mediated by the MEK/ERK-activated AP-1 transcription factors, JUNB and FOSB, which is responsible for the elevated expression of oncogenic FAM83A. Our data indicates that targeting the MEK/ERK-FAM83A feed-forward loop opens up additional avenues for clinical therapy that bypass targeting of oncogenic KRAS in aggressive pancreatic cancers.

Mechanism of prostaglandin E2-induced transcriptional up-regulation of Oncostatin-M by CREB and Sp1

Oncostatin-M (OSM) is a pleotropic cytokine belonging to the interleukin-6 family. Differential expression of OSM in response to varying stimuli and exhibiting repertoire of functions in different cells renders it challenging to study the mechanism of its expression. Prostaglandin E₂ (PGE₂) transcriptionally increased osm levels. In silico studies of ∼1 kb upstream of osm promoter region yielded the presence of CRE (cyclic AMP response element)-like sites at the distal end (CRE_osm). Deletion and point mutation of CRE_osm clearly indicated that this region imparted an important role in PGE₂-mediated transcription. Nuclear protein(s) from PGE₂-treated U937 cells, bound to this region, was identified as CRE-binding protein (CREB). CREB was phosphorylated on treatment and was found to be directly associated with CRE_osm The presence of cofactors p300 and CREB-binding protein in the complex was confirmed. A marked decrease in CREB phosphorylation, binding and transcriptional inhibition on treatment with PKA (protein kinase A) inhibitor, H89 (N-[2-[[3-(4-bromophenyl)-2-propenyl]amino]ethyl]-5-soquinolinesulfonamide), revealed the role of phosphorylated CREB in osm transcription. Additionally, other nuclear protein(s) were specifically associated with the proximal GC region (GC_osm) post PGE₂ treatment, later confirmed to be specificity protein 1 (Sp1). Interestingly, Sp1 bound to the proximal osm promoter was found to be associated with phospho-CREB-p300 complex bound to the distal osm promoter. Knockdown of Sp1 abrogated the expression and functionality of OSM. Thus, the present study conclusively proves that these transcription factors, bound at the distal and proximal promoter elements are found to associate with each other in a DNA-dependent manner and both are responsible for the PGE₂-mediated transcriptional up-regulation of Oncostatin-M.

Effects of arecoline on proliferation of oral squamous cell carcinoma cells by dysregulating c-Myc and miR-22, directly targeting oncostatin M

Arecoline, the major alkaloid of areca nut, is known to induce oral carcinogenesis, however, its mechanism is still needed to elucidate. This study investigated the effects of arecoline on cell viability and cell-cycle progression of oral squamous cell carcinoma (OSCC) cells as well as a relevant cellular gene expression. The results showed that a low concentration of arecoline (0.025 μg/ml) increased OSCC cell viability, proportion of cells in G2/M phase and cell proliferation. Simultaneously, it induced IL-6, STAT3 and c-Myc expression. Interestingly, c-myc promoter activity was also induced by arecoline. MiR-22 expression in arecoline-treated OSCC cells was suppressed and comparable to an upregulated c-Myc expression. In arecoline-treated OSCC cells, oncostatin M (OSM) expression was significantly upregulated and inversely correlated with miR-22 expression. Likewise, OSM expression and its post-transcriptional activity were significantly decreased in miR-22-transfected OSCC and 293FT cells. This result demonstrated that miR-22 directly targeted OSM. Interestingly, miR-22 played an important role as a tumor suppresser on suppressing cell proliferation, migration and cell-cycle progression of OSCC cells. This result suggested the effect of arecoline to promote cell proliferation and cell-cycle progression of OSCC cells might be involved in induction of c-Myc expression and reduction of miR-22 resulting in OSM upregulation.

Oncostatin M promotes cancer cell plasticity through cooperative STAT3-SMAD3 signaling

Increasing evidence supports the idea that cancer cell plasticity promotes metastasis and tumor recurrence, resulting in patient mortality. While it is clear that the tumor microenvironment (TME) contributes to cancer cell plasticity, the specific TME factors most actively controlling plasticity remain largely unknown. Here, we performed a screen to identify TME cytokines and growth factors that promote epithelial–mesenchymal plasticity, and acquisition of cancer stem cell (CSC) properties. Of 28 TME cytokines and growth factors tested, we identified Oncostatin M (OSM) as the most potent inducer of mesenchymal/CSC properties. OSM-induced plasticity was Signal Transducer and Activator of Transcription 3 (STAT3)-dependent, and also required a novel intersection with transforming growth factor-β (TGF-β)/SMAD signaling. OSM/STAT3 activation promoted SMAD3 nuclear accumulation, DNA binding and induced SMAD3-dependent transcriptional activity. Suppression of TGF-β receptor activity or ablation of SMAD3 or SMAD4, but not SMAD2, strongly suppressed OSM/STAT3-mediated plasticity. Moreover, removal of OSM or inhibition of STAT3 or SMAD3 resulted in a marked reversion to a non-invasive, epithelial phenotype. We propose that targeted blockade of the STAT3/SMAD3 axis in tumor cells may represent a novel therapeutic approach to prevent the plasticity required for metastatic progression and tumor recurrence.

Potent EMT and CSC Phenotypes Are Induced By Oncostatin-M in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is referred to as a silent killer due to the lack of clear symptoms, a lack of early detection methods, and a high frequency of metastasis at diagnosis. In addition, pancreatic cancer is remarkably resistant to chemotherapy, and clinical treatment options remain limited. The tumor microenvironment (TME) and associated factors are important determinants of metastatic capacity and drug resistance. Here, oncostatin M (OSM), an IL6 cytokine family member, was identified as an important driver of mesenchymal and cancer stem cell (CSC) phenotypes. Furthermore, the generation of cells that harbor mesenchymal/CSC properties following OSM exposure resulted in enhanced tumorigenicity, increased metastasis, and resistance to gemcitabine. OSM induced the expression of ZEB1, Snail (SNAI1), and OSM receptor (OSMR), engaging a positive feedback loop to potentiate the mesenchymal/CSC program. Suppression of JAK1/2 by ruxolitinib prevented STAT3-mediated transcription of ZEB1, SNAI1 and OSMR, as well as the emergence of a mesenchymal/CSC phenotype. Likewise, ZEB1 silencing, by shRNA-mediated knockdown, in OSM-driven mesenchymal/CSC reverted the phenotype back to an epithelial/non-CSC state. Importantly, the generation of cells with mesenchymal/CSC properties was unique to OSM, and not observed following IL6 exposure, implicating OSMR and downstream effector signaling as a distinct target in PDAC. Overall, these data demonstrate the capacity of OSM to regulate an epithelial-mesenchymal transition (EMT)/CSC plasticity program that promotes tumorigenic properties.Implications: Therapeutic targeting the OSM/OSMR axis within the TME may prevent or reverse the aggressive mesenchymal and CSC phenotypes associated with poor outcomes in patients with PDAC. Mol Cancer Res; 15(4); 478-88. ©2017 AACR.

Potent EMT and CSC Phenotypes Are Induced By Oncostatin-M in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is referred to as a silent killer due to the lack of clear symptoms, a lack of early detection methods, and a high frequency of metastasis at diagnosis. In addition, pancreatic cancer is remarkably resistant to chemotherapy, and clinical treatment options remain limited. The tumor microenvironment (TME) and associated factors are important determinants of metastatic capacity and drug resistance. Here, oncostatin M (OSM), an IL6 cytokine family member, was identified as an important driver of mesenchymal and cancer stem cell (CSC) phenotypes. Furthermore, the generation of cells that harbor mesenchymal/CSC properties following OSM exposure resulted in enhanced tumorigenicity, increased metastasis, and resistance to gemcitabine. OSM induced the expression of ZEB1, Snail (SNAI1), and OSM receptor (OSMR), engaging a positive feedback loop to potentiate the mesenchymal/CSC program. Suppression of JAK1/2 by ruxolitinib prevented STAT3-mediated transcription of ZEB1, SNAI1 and OSMR, as well as the emergence of a mesenchymal/CSC phenotype. Likewise, ZEB1 silencing, by shRNA-mediated knockdown, in OSM-driven mesenchymal/CSC reverted the phenotype back to an epithelial/non-CSC state. Importantly, the generation of cells with mesenchymal/CSC properties was unique to OSM, and not observed following IL6 exposure, implicating OSMR and downstream effector signaling as a distinct target in PDAC. Overall, these data demonstrate the capacity of OSM to regulate an epithelial-mesenchymal transition (EMT)/CSC plasticity program that promotes tumorigenic properties.Implications: Therapeutic targeting the OSM/OSMR axis within the TME may prevent or reverse the aggressive mesenchymal and CSC phenotypes associated with poor outcomes in patients with PDAC. Mol Cancer Res; 15(4); 478-88. ©2017 AACR.

STAT3-mediated SMAD3 activation underlies Oncostatin M-induced Senescence

Cytokines in the developing tumor microenvironment (TME) can drive transformation and subsequent progression toward metastasis. Elevated levels of the Interleukin-6 (IL-6) family cytokine Oncostatin M (OSM) in the breast TME correlate with aggressive, metastatic cancers, increased tumor recurrence, and poor patient prognosis. Paradoxically, OSM engages a tumor-suppressive, Signal Transducer and Activator of Transcription 3 (STAT3)-dependent senescence response in normal and non-transformed human mammary epithelial cells (HMEC). Here, we identify a novel link between OSM-activated STAT3 signaling and the Transforming Growth Factor-β (TGF-β) signaling pathway that engages senescence in HMEC. Inhibition of functional TGF-β/SMAD signaling by expressing a dominant-negative TGF-β receptor, treating with a TGF-β receptor inhibitor, or suppressing SMAD3 expression using a SMAD3-shRNA prevented OSM-induced senescence. OSM promoted a protein complex involving activated-STAT3 and SMAD3, induced the nuclear localization of SMAD3, and enhanced SMAD3-mediated transcription responsible for senescence. In contrast, expression of MYC (c-MYC) from a constitutive promoter abrogated senescence and strikingly, cooperated with OSM to promote a transformed phenotype, epithelial-mesenchymal transition (EMT), and invasiveness. Our findings suggest that a novel STAT3/SMAD3-signaling axis is required for OSM-mediated senescence that is coopted during the transformation process to confer aggressive cancer cell properties. Understanding how developing cancer cells bypass OSM/STAT3/SMAD3-mediated senescence may help identify novel targets for future "pro-senescence" therapies aiming to reengage this hidden tumor-suppressive response.

ADAM9 silencing inhibits breast tumor cells transmigration through blood and lymphatic endothelial cells

ADAMs are transmembrane multifunctional proteins that contain disintegrin and metalloprotease domains. ADAMs act in a diverse set of biological processes, including fertilization, inflammatory responses, myogenesis, cell migration, cell proliferation and ectodomain cleavage of membrane proteins. These proteins also have additional functions in pathological processes as cancer and metastasis development. ADAM9 is a member of ADAM protein family that is overexpressed in several types of human carcinomas. The aim of this study was to investigate the role of ADAM9 in hematogenous and lymphatic tumor cell dissemination assisting the development of new therapeutic tools. The role of ADAM9 in the interaction of breast tumor cells (MDA-MB-231) and endothelial cells was studied through RNA silencing. ADAM9 silencing in MDA-MB-231 cells had no influence in expression of several genes related to the metastatic process such as ADAM10, ADAM12, ADAM17, cMYC, MMP9, VEGF-A, VEGF-C, osteopontin and collagen XVII. However, there was a minor decrease in ADAM15 expression but an increase in that of MMP2. Moreover, ADAM9 silencing had no effect in the adhesion of MDA-MB-231 cells to vascular (HMEC-1 and HUVEC) and lymphatic cells (HMVEC-dLyNeo) under flow condition. Nevertheless, siADAM9 in MDA-MB-231 decreased transendothelial cell migration in vitro through HUVEC, HMEC-1 and HMVEC-dLyNeo (50%, 40% and 32% respectively). These results suggest a role for ADAM9 on the extravasation step of the metastatic cascade through both blood and lymph vessels.

Effect of human papillomavirus 16 oncoproteins on oncostatin M upregulation in oral squamous cell carcinoma

Human papillomavirus (HPV) infection modulates several host cytokines contributing to cancer development. Oncostatin M (OSM), an IL-6 family cytokine, acts to promote cell senescence and inhibit growth. Its dysregulation promotes cell survival, cell proliferation and metastasis in various malignancies. The effect of HPV on OSM dysregulation has not been investigated. To elucidate this, immunohistochemistry was used on formalin-fixed, paraffin-embedded oral squamous cell carcinoma (OSCC) tissues: HPV-positive (50) and HPV-negative (50) cases. Immortalized human cervical keratinocytes expressing HPV16E6 (HCK1T, Tet-On system) were used to demonstrate the role of HPV16E6 in OSM expression. In addition, a vector containing HPV16E6/E7 was transiently transfected into oral cancer cell lines. Cell viability, cell-cycle progression and cell migration were evaluated using flow cytometry and a wound healing assay, respectively. The results showed various intensities of OSM expression in OSCC. Interestingly, the median percentages of strongly stained cells were significantly higher in HPV-positive OSCCs than in HPV-negative OSCCs. To explore the role of HPV oncoproteins on OSM expression, the expression of HPV16E6 in the HCK1T Tet-On condition was induced by doxycycline and HPV16E6 was found to significantly upregulate levels of OSM mRNA and protein, with concomitant upregulation of c-Myc. In addition, the levels of OSM mRNA and protein in E6/E7 transiently transfected oral cancer cells also gradually increased in a time-dependent manner and these transfected cells showed greater viability and higher migration rates and cell-cycle progression than controls. This result demonstrates that HPV16 oncoproteins upregulate OSM and play an important role to promote OSCC development.

Cancer Stem Cell Plasticity Drives Therapeutic Resistance

The connection between epithelial-mesenchymal (E-M) plasticity and cancer stem cell (CSC) properties has been paradigm-shifting, linking tumor cell invasion and metastasis with therapeutic recurrence. However, despite their importance, the molecular pathways involved in generating invasive, metastatic, and therapy-resistant CSCs remain poorly understood. The enrichment of cells with a mesenchymal/CSC phenotype following therapy has been interpreted in two different ways. The original interpretation posited that therapy kills non-CSCs while sparing pre-existing CSCs. However, evidence is emerging that suggests non-CSCs can be induced into a transient, drug-tolerant, CSC-like state by chemotherapy. The ability to transition between distinct cell states may be as critical for the survival of tumor cells following therapy as it is for metastatic progression. Therefore, inhibition of the pathways that promote E-M and CSC plasticity may suppress tumor recurrence following chemotherapy. Here, we review the emerging appreciation for how plasticity confers therapeutic resistance and tumor recurrence.

STAT3 in Cancer-Friend or Foe?

The roles and significance of STAT3 in cancer biology have been extensively studied for more than a decade. Mounting evidence has shown that constitutive activation of STAT3 is a frequent biochemical aberrancy in cancer cells, and this abnormality directly contributes to tumorigenesis and shapes many malignant phenotypes in cancer cells. Nevertheless, results from more recent experimental and clinicopathologic studies have suggested that STAT3 also can exert tumor suppressor effects under specific conditions. Importantly, some of these studies have demonstrated that STAT3 can function either as an oncoprotein or a tumor suppressor in the same cell type, depending on the specific genetic background or presence/absence of specific coexisting biochemical defects. Thus, in the context of cancer biology, STAT3 can be a friend or foe. In the first half of this review, we will highlight the “evil” features of STAT3 by summarizing its oncogenic functions and mechanisms. The differences between the canonical and non-canonical pathway will be highlighted. In the second half, we will summarize the evidence supporting that STAT3 can function as a tumor suppressor. To explain how STAT3 may mediate its tumor suppressor effects, we will discuss several possible mechanisms, one of which is linked to the role of STAT3β, one of the two STAT3 splicing isoforms. Taken together, it is clear that the roles of STAT3 in cancer are multi-faceted and far more complicated than one appreciated previously. The new knowledge has provided us with new approaches and strategies when we evaluate STAT3 as a prognostic biomarker or therapeutic target.

STAT3 and epithelial-mesenchymal transitions in carcinomas

Cellular programs coupled to cycles of epithelial–mesenchymal transitions (EMTs) play critical roles during embryogenesis, as well as during tissue development, remodeling, and repair. Research over the last decade has established the importance of an ever-expanding list of master EMT transcription factors, whose activity is regulated by STAT3 and function to stimulate the rapid transition of cells between epithelial and mesenchymal phenotypes. Importantly, inappropriate reactivation of embryonic EMT programs in carcinoma cells underlies their metastasis to distant organ sites, as well as their acquisition of stem cell-like and chemoresistant phenotypes operant in eliciting disease recurrence. Thus, targeted inactivation of master EMT transcription factors may offer new inroads to alleviate metastatic disease. Here we review the molecular, cellular, and microenvironmental factors that contribute to the pathophysiological activities of STAT3 during its regulation of EMT programs in human carcinomas.

HiJAK'd Signaling; the STAT3 Paradox in Senescence and Cancer Progression

Clinical and epidemiological data have associated chronic inflammation with cancer progression. Most tumors show evidence of infiltrating immune and inflammatory cells, and chronic inflammatory disorders are known to increase the overall risk of cancer development. While immune cells are often observed in early hyperplastic lesions in vivo, there remains debate over whether these immune cells and the cytokines they produce in the developing hyperplastic microenvironment act to inhibit or facilitate tumor development. The interleukin-6 (IL-6) family of cytokines, which includes IL-6 and oncostatin M (OSM), among others (LIF, CT-1, CNTF, and CLC), are secreted by immune cells, stromal cells, and epithelial cells, and regulate diverse biological processes. Each of the IL-6 family cytokines signals through a distinct receptor complex, yet each receptor complex uses a shared gp130 subunit, which is critical for signal transduction following cytokine binding. Activation of gp130 results in the activation of Signal Transducer and Activator of Transcription 3 (STAT3), and the Mitogen-Activated Protein Kinase (MAPK) and Phosphatidylinositol 3-Kinase (PI3K) signaling cascades. Tumor suppressive signaling can often be observed in normal cells following prolonged STAT3 activation. However, there is mounting evidence that the IL-6 family cytokines can contribute to later stages of tumor progression in many ways. Here we will review how the microenvironmental IL-6 family cytokine OSM influences each stage of the transformation process. We discuss the intrinsic adaptations a developing cancer cell must make in order to tolerate and circumvent OSM-mediated growth suppression, as well as the OSM effectors that are hijacked during tumor expansion and metastasis. We propose that combining current therapies with new ones that suppress the signals generated from the tumor microenvironment will significantly impact an oncologist’s ability to treat cancer.

Oncostatin M receptor is a novel therapeutic target in cervical squamous cell carcinoma

Cervical carcinoma is the second most common cause of cancer deaths in women worldwide. Treatments have not changed for decades and survival rates for advanced disease remain low. An exciting new molecular target for the treatment of cervical squamous cell carcinoma (SCC), and possibly for SCCs at other anatomical sites, is the oncostatin M receptor (OSMR). This cell surface cytokine receptor is commonly copy number gained and overexpressed in advanced cervical SCC, changes that are associated with significantly worse clinical outcomes. OSMR overexpression in cervical SCC cells results in enhanced responsiveness to the major ligand oncostatin M (OSM), which induces several pro-malignant effects, including a pro-angiogenic phenotype and increased cell migration and invasiveness. OSMR is a strong candidate for antibody-mediated inhibition, a strategy that has had a major impact on haematological malignancies and various solid tumours such as HER2-positive breast cancers.

The enigmatic cytokine oncostatin m and roles in disease

Oncostatin M is a secreted cytokine involved in homeostasis and in diseases involving chronic inflammation. It is a member of the gp130 family of cytokines that have pleiotropic functions in differentiation, cell proliferation, and hematopoetic, immunologic, and inflammatory networks. However, Oncostatin M also has activities novel to mediators of this cytokine family and others and may have fundamental roles in mechanisms of inflammation in pathology. Studies have explored Oncostatin M functions in cancer, bone metabolism, liver regeneration, and conditions with chronic inflammation including rheumatoid arthritis, lung and skin inflammatory disease, atherosclerosis, and cardiovascular disease. This paper will review Oncostatin M biology in a historical fashion and focus on its unique activities, in vitro and in vivo, that differentiate it from other cytokines and inspire further study or consideration in therapeutic approaches.

Interleukin-6 and oncostatin-M synergize with the PI3K/AKT pathway to promote aggressive prostate malignancy in mouse and human tissues

Chronic inflammation has been proposed as an etiological and progression factor in prostate cancer. In this study, we used a dissociated prostate tissue recombination system to interrogate the role of interleukin 6 (IL6) and the related cytokine oncostatin-M (OSM) in the initiation and progression of prostate cancer. We identified that prostatic intraepithelial neoplasia (PIN) lesions induced by PTEN loss of function (PTEN(LOF)) progress to invasive adenocarcinoma following paracrine expression of either cytokine. Increased expression of OSM was also able to drive progression of benign human epithelium when combined with constitutively activated AKT. Malignant progression in the mouse was associated with invasion into the surrounding mesenchyme and increased activation of STAT3 in PTEN(LOF) grafts expressing IL6 or OSM. Collectively, our work indicates that pro-inflammatory cytokines such as IL6 or OSM could activate pathways associated with prostate cancer progression and synergize with cell-autonomous oncogenic events to promote aggressive malignancy.

IMPLICATIONS

Increased expression of IL6 or OSM synergizes with loss of PTEN to promote invasive prostate cancer. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/early/2013/09/02/1541-7786.MCR-13-0238/F1.large.jpg.

Oncostatin M is a growth factor for Ewing sarcoma

Primary bone tumors, osteosarcomas and chondrosarcomas, derive from mesenchymal stem cells committed into osteoblasts and chondrocytes; in Ewing sarcomas (ESs), the oncogenic fusion protein EWS-FLI1 prevents mesenchymal differentiation and induces neuroectodermic features. Oncostatin M (OSM) is a cytokine from the IL-6 family that modulates proliferation and differentiation in numerous cells. The basis for inhibition versus induction of proliferation by this cytokine is obscure, although MYC was described as a potent molecular switch in OSM signaling. We show herein that, in contrast to osteosarcomas and chondrosarcomas, for which OSM was cytostatic, OSM induced proliferation of ES cell lines. Knockdown experiments demonstrated that growth induction by OSM depends on both types I [leukemia inhibitory factor receptor (LIFR)] and II [OSM receptor (OSMR)] receptors, high STAT3 activation, and induction of MYC to a high expression level. Indeed, ES cell lines, mice xenografts, and patient biopsy specimens poorly expressed LIF, precluding LIFR lysosomal degradation and OSMR transcriptional induction, thus leading to a high LIFR/OSMR ratio. Because other neuroectodermic tumors (ie, glioma, medulloblastoma, and neuroblastoma) had a similar expression profile, the main role of EWS-FLI1 could be through maintenance of stemness and neuroectodermic features, characterized by a low LIF, a high LIFR/OSMR ratio, and high MYC expression. Thus, this study on rare bone malignancies gives valuable insights on more common cancer regulatory mechanisms and could provide new therapeutic opportunities.

Oncostatin M suppresses oestrogen receptor-α expression and is associated with poor outcome in human breast cancer

The most important clinical biomarker for breast cancer management is oestrogen receptor alpha (ERα). Tumours that express ER are candidates for endocrine therapy and are biologically less aggressive, while ER-negative tumours are largely treated with conventional chemotherapy and have a poor prognosis. Despite its significance, the mechanisms regulating ER expression are poorly understood. We hypothesised that the inflammatory cytokine oncostatin M (OSM) can downregulate ER expression in breast cancer. Recombinant OSM potently suppressed ER protein and mRNA expression in vitro in a dose- and time-dependent manner in two human ER+ breast cancer cell lines, MCF7 and T47D. This was dependent on the expression of OSM receptor beta (OSMRβ) and could be blocked by inhibition of the MEKK1/2 mitogen-activated protein kinases. ER loss was also necessary for maximal OSM-induced signal transduction and migratory activity. In vivo, high expression of OSM and OSMR mRNA (determined by RT-PCR) was associated with reduced ER (P<0.01) and progesterone receptor (P<0.05) protein levels in a cohort of 70 invasive breast cancers. High OSM and OSMR mRNA expression was also associated with low expression of ESR1 (ER, P<0.0001) and ER-regulated genes in a previously published breast cancer gene expression dataset (n=321 cases). In the latter cohort, high OSMR expression was associated with shorter recurrence-free and overall survival in univariate (P<0.0001) and multivariate (P=0.022) analyses. OSM signalling may be a novel factor causing suppression of ER and disease progression in breast cancer.