Transforming growth factor-beta1 activates interleukin-6 expression in prostate cancer cells through the synergistic collaboration of the Smad2, p38-NF-kappaB, JNK, and Ras signaling pathways

Nuclear factor-κB activation by transforming growth factor-β1 drives tumour microenvironment-mediated drug resistance in neuroblastoma

BACKGROUND

Intrinsic and extrinsic factors in the tumour microenvironment (TME) contribute to therapeutic resistance. Here we demonstrate that transforming growth factor (TGF)-β1 produced in the TME increased drug resistance of neuroblastoma (NB) cells.

METHODS

Human NB cell lines were tested in vitro for their sensitivity to Doxorubicin (DOX) and Etoposide (ETOP) in the presence of tumour-associated macrophages (TAM) and mesenchymal stromal cells/cancer-associated fibroblasts (MSC/CAF). These experiments were validated in xenotransplanted and primary tumour samples.

RESULTS

Drug resistance was associated with an increased expression of efflux transporter and anti-apoptotic proteins. Upregulation was dependent on activation of nuclear factor (NF)-κB by TGF-β-activated kinase (TAK1) and SMAD2. Resistance was reversed upon pharmacologic and genetic inhibitions of NF-κB, and TAK1/SMAD2. Interleukin-6, leukaemia inhibitory factor and oncostatin M were upregulated by this TGF-β/TAK1/NF-κB/SMAD2 signalling pathway contributing to drug resistance via an autocrine loop activating STAT3. An analysis of xenotransplanted NB tumours revealed an increased presence of phospho (p)-NF-κB in tumours co-injected with MSC/CAF and TAM, and these tumours failed to respond to Etoposide but responded if treated with a TGF-βR1/ALK5 inhibitor. Nuclear p-NF-κB was increased in patient-derived tumours rich in TME cells.

CONCLUSIONS

The data provides a novel insight into a targetable mechanism of environment-mediated drug resistance.

Effects of curcumin and ursolic acid in prostate cancer: A systematic review

The major barriers to phytonutrients in prostate cancer therapy are non-specific mechanisms and bioavailability issues. Studies have pointed to a synergistic combination of curcumin (CURC) and ursolic acid (UA). We investigate this combination using a systematic review process to assess the most likely mechanistic pathway and human testing in prostate cancer. We used the PRISMA statement to screen titles, abstracts, and the full texts of relevant articles and performed a descriptive analysis of the literature reviewed for study inclusion and consensus of the manuscript. The most common molecular and cellular pathway from articles reporting on the pathways and effects of CURC (n = 173) in prostate cancer was NF-κB (n = 25, 14.5%). The most common molecular and cellular pathway from articles reporting on the pathways and effects of UA (n = 24) in prostate cancer was caspase 3/caspase 9 (n = 10, 41.6%). The three most common molecular and cellular pathway from articles reporting on the pathways and effects of both CURC and UA (n = 193) in prostate cancer was NF-κB (n = 28, 14.2%), Akt (n = 22, 11.2%), and androgen (n = 19, 9.6%). Therefore, we have identified the potential synergistic target pathways of curcumin and ursolic acid to involve NF-κB, Akt, androgen receptors, and apoptosis pathways. Our review highlights the limited human studies and specific effects in prostate cancer.

Inflammation in Prostate Cancer: Exploring the Promising Role of Phenolic Compounds as an Innovative Therapeutic Approach

Prostate cancer (PCa) remains a significant global health concern, being a major cause of cancer morbidity and mortality worldwide. Furthermore, profound understanding of the disease is needed. Prostate inflammation caused by external or genetic factors is a central player in prostate carcinogenesis. However, the mechanisms underlying inflammation-driven PCa remain poorly understood. This review dissects the diagnosis methods for PCa and the pathophysiological mechanisms underlying the disease, clarifying the dynamic interplay between inflammation and leukocytes in promoting tumour development and spread. It provides updates on recent advances in elucidating and treating prostate carcinogenesis, and opens new insights for the use of bioactive compounds in PCa. Polyphenols, with their noteworthy antioxidant and anti-inflammatory properties, along with their synergistic potential when combined with conventional treatments, offer promising prospects for innovative therapeutic strategies. Evidence from the use of polyphenols and polyphenol-based nanoparticles in PCa revealed their positive effects in controlling tumour growth, proliferation, and metastasis. By consolidating the diverse features of PCa research, this review aims to contribute to increased understanding of the disease and stimulate further research into the role of polyphenols and polyphenol-based nanoparticles in its management.

Suppression of TGFβ-Induced Interleukin-6 Secretion by Sinulariolide from Soft Corals through Attenuation of the p38-NF-kB Pathway in Carcinoma Cells

Sinulariolide (SC-1) is a natural product extracted from the cultured-type soft coral Sinularia flexibilis and possesses anti-inflammation, anti-proliferative, and anti-migratory in several types of cancer cells. However, the molecular pathway behind its effects on inflammation remains poorly understood. Since inflammatory cytokines such as TGFβ, TNFα, IL-1, IL-6, and IL-8 activate transcription factors such as Smads, NF-κB, STAT3, Snail, Twist, and Zeb that drive the epithelial-to-mesenchymal transition (EMT), in this study, we focus on the investigation in effects of SC-1 on TGFβ-induced interleukin-6 (IL-6) releases in an in vitro cell culture model. We showed that both intracellular IL-6 expression and secretion were stimulated by TGFβ and associated with strong upregulation of IL-6 mRNA and increased transcription in A549 cells. SC-1 blocked TGFβ-induced secretion of IL-6 while showing no effect on the induction of fibronectin and plasminogen activator inhibitor-1 genes, indicating that SC-1 interferes with only a subset of TGFβ activities. In addition, SC-1 inhibits TGFβ-induced IL-6 by suppressing p38 MAPK signaling and subsequently inhibits NF-κB and its nuclear translocation without affecting the canonical Smad pathway and receptor turnover. Overall, these data suggest that p38 may involve in the inhibition of SC-1 in IL-6 release, thus illustrating an inhibitory effect for SC-1 in the suppression of inflammation, EMT phenotype, and tumorigenesis.

Inflammatory Cytokine: An Attractive Target for Cancer Treatment

The relationship between inflammation and cancer has attracted attention for a long time. The inflammatory tumor microenvironment consists of inflammatory cells, chemokines, cytokines, and signaling pathways. Among them, inflammatory cytokines play an especially pivotal role in cancer development, prognosis, and treatment. Interleukins, tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta (TGF-β), interferons, and vascular endothelial growth factor (VEGF) are the representative inflammatory cytokines in various cancers, which may promote or inhibit cancer progression. The pro-inflammatory cytokines are associated with advanced cancer stages, resistance to immunotherapy, and poor prognoses, such as in objective response and disease control rates, and progression-free and overall survival. In this review, we selected colorectal, pancreatic, breast, gastric, lung, and prostate cancers, which are well-reported for an association between cancer and inflammatory cytokines. The related cytokines and their effects on each cancer’s development and prognosis were summarized. In addition, the treatment strategies targeting inflammatory cytokines in each carcinoma were also described here. By understanding the biological roles of cancer-related inflammatory cytokines, we may modulate the inflammatory tumor microenvironment for potential cancer treatment.

Curcuminoids as Modulators of EMT in Invasive Cancers: A Review of Molecular Targets With the Contribution of Malignant Mesothelioma Studies

Curcuminoids, which include natural acyclic diarylheptanoids and the synthetic analogs of curcumin, have considerable potential for fighting against all the characteristics of invasive cancers. The epithelial-to-mesenchymal transition (EMT) is a fundamental process for embryonic morphogenesis, however, the last decade has confirmed it orchestrates many features of cancer invasiveness, such as tumor cell stemness, metabolic rewiring, and drug resistance. A wealth of studies has revealed EMT in cancer is in fact driven by an increasing number of parameters, and thus understanding its complexity has now become a cornerstone for defining future therapeutic strategies dealing with cancer progression and metastasis. A specificity of curcuminoids is their ability to target multiple molecular targets, modulate several signaling pathways, modify tumor microenvironments and enhance the host’s immune response. Although the effects of curcumin on these various parameters have been the subject of many reviews, the role of curcuminoids against EMT in the context of cancer have never been reviewed so far. This review first provides an updated overview of all EMT drivers, including signaling pathways, transcription factors, non-coding RNAs (ncRNAs) and tumor microenvironment components, with a special focus on the most recent findings. Secondly, for each of these drivers the effects of curcumin/curcuminoids on specific molecular targets are analyzed. Finally, we address some common findings observed between data reported in the literature and the results of investigations we conducted on experimental malignant mesothelioma, a model of invasive cancer representing a useful tool for studies on EMT and cancer.

Enzalutamide-induced and PTH1R-mediated TGFBR2 degradation in osteoblasts confers resistance in prostate cancer bone metastases

Enzalutamide resistance has been observed in approximately 50% of patients with prostate cancer (PCa) bone metastases. Therefore, there is an urgent need to investigate the mechanisms and develop strategies to overcome resistance. We observed enzalutamide resistance in bone lesion development induced by PCa cells in mouse models. We found that the bone microenvironment was indispensable for enzalutamide resistance because enzalutamide significantly inhibited the growth of subcutaneous C4-2B tumors and the proliferation of C4-2B cells isolated from the bone lesions, and the resistance was recapitulated only when C4-2B cells were co-cultured with osteoblasts. In revealing how osteoblasts contribute to enzalutamide resistance, we found that enzalutamide decreased TGFBR2 protein expression in osteoblasts, which was supported by clinical data. This decrease was possibly through PTH1R-mediated endocytosis. We showed that PTH1R blockade rescued enzalutamide-mediated decrease in TGFBR2 levels and enzalutamide responses in C4-2B cells that were co-cultured with osteoblasts. This is the first study to reveal the contribution of the bone microenvironment to enzalutamide resistance and identify PTH1R as a feasible target to overcome the resistance in PCa bone metastases.

Role of FRG1 in predicting the overall survivability in cancers using multivariate based optimal model

FRG1 has a role in tumorigenesis and angiogenesis. Our preliminary analysis showed that FRG1 mRNA expression is associated with overall survival (OS) in certain cancers, but the effect varies. In cervix and gastric cancers, we found a clear difference in the OS between the low and high FRG1 mRNA expression groups, but the difference was not prominent in breast, lung, and liver cancers. We hypothesized that FRG1 expression level could affect the functionality of the correlated genes or vice versa, which might mask the effect of a single gene on the OS analysis in cancer patients. We used the multivariate Cox regression, risk score, and Kaplan Meier analyses to determine OS in a multigene model. STRING, Cytoscape, HIPPIE, Gene Ontology, and DAVID (KEGG) were used to deduce FRG1 associated pathways. In breast, lung, and liver cancers, we found a distinct difference in the OS between the low and high FRG1 mRNA expression groups in the multigene model, suggesting an independent role of FRG1 in survival. Risk scores were calculated based upon regression coefficients in the multigene model. Low and high-risk score groups showed a significant difference in the FRG1 mRNA expression level and OS. HPF1, RPL34, and EXOSC9 were the most common genes present in FRG1 associated pathways across the cancer types. Validation of the effect of FRG1 mRNA expression level on these genes by qRT-PCR supports that FRG1 might be an upstream regulator of their expression. These genes may have multiple regulators, which also affect their expression, leading to the masking effect in the survival analysis. In conclusion, our study highlights the role of FRG1 in the survivability of cancer patients in tissue-specific manner and the use of multigene models in prognosis.

Circulating Tumour Cells (CTCs) in NSCLC: From Prognosis to Therapy Design

Designing optimal (neo)adjuvant therapy is a crucial aspect of the treatment of non-small-cell lung carcinoma (NSCLC). Standard methods of chemotherapy, radiotherapy, and immunotherapy represent effective strategies for treatment. However, in some cases with high metastatic activity and high levels of circulating tumour cells (CTCs), the efficacy of standard treatment methods is insufficient and results in treatment failure and reduced patient survival. CTCs are seen not only as an isolated phenomenon but also a key inherent part of the formation of metastasis and a key factor in cancer death. This review discusses the impact of NSCLC therapy strategies based on a meta-analysis of clinical studies. In addition, possible therapeutic strategies for repression when standard methods fail, such as the administration of low-toxicity natural anticancer agents targeting these phenomena (curcumin and flavonoids), are also discussed. These strategies are presented in the context of key mechanisms of tumour biology with a strong influence on CTC spread and metastasis (mechanisms related to tumour-associated and -infiltrating cells, epithelial–mesenchymal transition, and migration of cancer cells).

Embryonic protein NODAL regulates the breast tumor microenvironment by reprogramming cancer-derived secretomes

The tumor microenvironment (TME) is an important mediator of breast cancer progression. Cancer-associated fibroblasts constitute a major component of the TME and may originate from tissue-associated fibroblasts or infiltrating mesenchymal stromal cells (MSCs). The mechanisms by which cancer cells activate fibroblasts and recruit MSCs to the TME are largely unknown, but likely include deposition of a pro-tumorigenic secretome. The secreted embryonic protein NODAL is clinically associated with breast cancer stage and promotes tumor growth, metastasis, and vascularization. Herein, we show that NODAL expression correlates with the presence of activated fibroblasts in human triple-negative breast cancers and that it directly induces Cancer-associated fibroblasts phenotypes. We further show that NODAL reprograms cancer cell secretomes by simultaneously altering levels of chemokines (e.g., CXCL1), cytokines (e.g., IL-6) and growth factors (e.g., PDGFRA), leading to alterations in MSC chemotaxis. We therefore demonstrate a hitherto unappreciated mechanism underlying the dynamic regulation of the TME.

Regulatory T cells promote glioma cell stemness through TGF-β-NF-κB-IL6-STAT3 signaling

Glioma stem cells (GSCs) contribute to the malignant growth of glioma, but little is known about the interaction between GSCs and tumor microenvironment. Here, we found that intense infiltration of regulatory T cells (Tregs) facilitated the qualities of GSCs through TGF-β secretion that helped coordinately tumor growth. Mechanistic investigations indicated that TGF-β acted on cancer cells to induce the core cancer stem cell-related genes CD133, SOX2, NESTIN, MUSASHI1 and ALDH1A expression and spheres formation via NF-κB–IL6–STAT3 signaling pathway, resulting in the increased cancer stemness and tumorigenic potential. Furthermore, Tregs promoted glioma tumor growth, and this effect could be abrogated with blockade of IL6 receptor by tocilizumab which also demonstrated certain level of therapeutic efficacy in xenograft model. Additionally, expression levels of CD133, IL6 and TGF-β were found to serve as prognosis markers of glioma patients. Collectively, our findings reveal a new immune-associated mechanism underlying Tregs-induced GSCs. Moreover, efforts to target this network may be an effective strategy for treating glioma.

Merkel cell polyomavirus small tumour antigen activates the p38 MAPK pathway to enhance cellular motility

Merkel cell carcinoma (MCC) is an aggressive skin cancer with high rates of recurrence and metastasis. Merkel cell polyomavirus (MCPyV) is associated with the majority of MCC cases. MCPyV-induced tumourigenesis is largely dependent on the expression of the small tumour antigen (ST). Recent findings implicate MCPyV ST expression in the highly metastatic nature of MCC by promoting cell motility and migration, through differential expression of cellular proteins that lead to microtubule destabilisation, filopodium formation and breakdown of cell-cell junctions. However, the molecular mechanisms which dysregulate these cellular processes are yet to be fully elucidated. Here, we demonstrate that MCPyV ST expression activates p38 MAPK signalling to drive cell migration and motility. Notably, MCPyV ST-mediated p38 MAPK signalling occurs through MKK4, as opposed to the canonical MKK3/6 signalling pathway. In addition, our results indicate that an interaction between MCPyV ST and the cellular phospatase subunit PP4C is essential for its effect on p38 MAPK signalling. These results provide novel opportunities for the treatment of metastatic MCC given the intense interest in p38 MAPK inhibitors as therapeutic agents.

Interleukin-6 Function and Targeting in Prostate Cancer

Interleukin-6 (IL-6) is a proinflammatory cytokine, which is involved in pathogenesis of several cancers. Its expression and function in prostate cancer have been extensively studied in cellular models and clinical specimens. High levels of IL-6 were detected in conditioned media from cells which do not respond to androgens. Increased phosphorylation of signal transducer and activator of transcription (STAT)3 factor which is induced in response to IL-6 is one of the typical features of prostate cancer. However, reports in the literature show regulation of neuroendocrine phenotype by IL-6. Effects of IL-6 on stimulation of proliferation, migration, and invasion lead to the establishment of experimental and clinical approaches to target IL-6. In prostate cancer, anti-IL-6 antibodies were demonstrated to inhibit growth in vitro and in vivo. Clinically, application of anti-IL-6 therapies did not improve survival of patients with metastatic prostate cancer. However, clinical trial design in the future may include different treatment schedule and combinations with experimental and clinical therapies. Endogenous inhibitors of IL-6 such as suppressors of cytokine signaling and protein inhibitors of activated STAT have variable effects on prostate cells, depending on presence or absence of the androgen receptor.

TAK1 Inhibitor Enhances the Therapeutic Treatment for Glioblastoma

Glioblastoma (GBM) is a brain tumor characterized by poor therapeutic response and overall survival. Despite relevant progress in conventional treatments represented by the clinical use of temozolomide (TMZ), a combination of approaches might be a possible future direction for treating GBM. Transforming growth factor-beta-activated kinase-1 (TAK1) is an essential component in genotoxic stresses-induced NF-κB-activation and mitogen-activated protein kinase (MAPK)-pathways; however, the role of TAK1 in GBM-chemoresistance remains unknown. This study aimed to verify, in GBM human cell lines, in an in vivo U87-xenograft model and in TMZ-treated-patients, the effect of TAK1 inhibition on the sensitivity of GBM cells to chemotherapy. In vitro model, using GBM cell lines, showed that 5Z-7-oxozeaenol augmented the cytotoxic effects of TMZ, blocking TMZ-induced NF-κB-activation, reducing DNA-damage and enhancing TMZ-induced apoptosis in GMB cell lines. We showed a reduction in tumor burden as well as tumor volume in the xenograft model following the treatment with 5Z-7-oxozaenol associated with TMZ. Our results showed a significant up-regulation in TAK1, p-p38, p-JNK and NF-κB in glioblastoma TMZ-treated-patients and denoted the role of 5Z-7-oxozeaenol in increasing the sensitivity of GBM cells to chemotherapy, proving to be an effective coadjuvant to current GBM chemotherapeutic regimens, suggesting a new option for therapeutic treatment of GBM.

Homeostasis: apoptosis and cell cycle in normal and pathological prostate

Prostatic diseases such as hyperplasia and cancer are a consequence of glandular aging due to the loss of homeostasis. Glandular homeostasis is guaranteed by the delicate balance between production and cell death. Both cell renewal and apoptosis are part of this delicate balance. We will explore the predictive capacity for biochemical progression, following prostatectomy, of some members of the Bcl-2 family and of proteins involved in cell cycle inhibition in conjunction with established classical markers. The expression of Bcl-2, Bcl-xL, Mcl-1, Bax, Bim, Bad, PUMA, Noxa, p21, p27, Rb and p53 were analyzed by immunochemistry in 86 samples of radical prostatectomy and correlated with each of the markers established clinicopathological tests using statistical tests such as Sperman, Kaplan-Meier curves, unifactorial Cox, and multifactorial. The most relevant results are: (1) Positive correlation between: p27 with clinical T stage; and PUMA with pathological T stage; (2) Negative correlation between: Bcl-2 with clinical T stage, Bcl-xL with survival, Noxa and pRb with Gleason score.Our results suggest that the expression of Bcl-2, Bcl-xL, PUMA, Noxa, p27, and Rb were related to some of the classic markers established to predict biochemical progression after prostatectomy.

Exploring Dysregulated Signaling Pathways in Cancer

Cancer cell biology takes advantage of identifying diverse cellular signaling pathways that are disrupted in cancer. Signaling pathways are an important means of communication from the exterior of cell to intracellular mediators, as well as intracellular interactions that govern diverse cellular processes. Oncogenic mutations or abnormal expression of signaling components disrupt the regulatory networks that govern cell function, thus enabling tumor cells to undergo dysregulated mitogenesis, to resist apoptosis, and to promote invasion to neighboring tissues. Unraveling of dysregulated signaling pathways may advance the understanding of tumor pathophysiology and lead to the improvement of targeted tumor therapy. In this review article, different signaling pathways and how their dysregulation contributes to the development of tumors have been discussed.

NRASQ61K melanoma tumor formation is reduced by p38-MAPK14 activation in zebrafish models and NRAS-mutated human melanoma cells

Oncogenic BRAF and NRAS mutations drive human melanoma initiation. We used transgenic zebrafish to model NRAS-mutant melanoma, and the rapid tumor onset allowed us to study candidate tumor suppressors. We identified P38α-MAPK14 as a potential tumor suppressor in The Cancer Genome Atlas melanoma cohort of NRAS-mutant melanomas, and overexpression significantly increased the time to tumor onset in transgenic zebrafish with NRAS-driven melanoma. Pharmacological activation of P38α-MAPK14 using anisomycin reduced in vitro viability of melanoma cultures, which we confirmed by stable overexpression of p38α. We observed that the viability of MEK inhibitor resistant melanoma cells could be reduced by combined treatment of anisomycin and MEK inhibition. Our study demonstrates that activating the p38α-MAPK14 pathway in the presence of oncogenic NRAS abrogates melanoma in vitro and in vivo. SIGNIFICANCE: The significance of our study is in the accountability of NRAS mutations in melanoma. We demonstrate here that activation of p38α-MAPK14 pathway can abrogate NRAS-mutant melanoma which is contrary to the previously published role of p38α-MAPK14 pathway in BRAF mutant melanoma. These results implicate that BRAF and NRAS-mutant melanoma may not be identical biologically. We also demonstrate the translational benefit of our study by using a small molecule compound-anisomycin (already in use for other diseases in clinical trials) to activate p38α-MAPK14 pathway.

Inhibiting MAPK14 showed anti-prolactinoma effect

BACKGROUND

The specific underlying pathogenesis of prolactinoma has not been clarified yet, to the best of our knowledge. p38 mitogen-activated protein kinase (MAPK) signaling including p38α MAPK (MAPK14), p38β (MAPK11), p38γ (MAPK12) and p38δ (MAPK13) is associated with the development and progression of several types of cancer.

METHODS

Immunofluorescence analysis was performed on the prolactin (PRL) and MAPK14 expressions of pituitary gland in C57BL/6 mice and human prolactinoma specimen. In the present study, the role of MAPK14 in prolactinoma was determined using estradiol-induced mice and dopamine D2 receptor knockout (DRD2^-/-) mice models in C57BL/6 wild-type (WT), MAPK14^-/- and DRD2^-/-MAPK14^+/- mice. GH3 cells were transfected with different sets of MAPK14 small interfering RNA, which to study MAPK14 and PRL expression in GH3 cells.

RESULTS

Immunofluorescence analysis showed that PRL and MAPK14 expression were colocalized and increased in the pituitary gland of mice and human prolactinoma specimen compared with the control specimen. It was shown that PRL and MAPK14 expression was colocalized and increased significantly in the pituitary gland of estradiol-injected prolactinoma mice compared with the control mice. Knockout of MAPK14 significantly inhibited tumor overgrowth, and PRL expression was decreased in estradiol-induced mice. Furthermore, MAPK14 knockout of DRD2^-/-MAPK14^+/- mice significantly reduced the overgrowth of pituitary gland and PRL production and secretion compared with DRD2^-/- mice. MAPK14 knockout using siRNA inhibited PRL production in GH3 cells.

CONCLUSION

These results suggest that MAPK14 serves a promoting role in the formation of prolactinoma, and highlights the potential of MAPK14 as a potential therapeutic target in the treatment of prolactinoma.

TNF-α controls Lipocalin-2 expression in PC-3 prostate cancer cells

Prostate cancer (PCa) is one of the most common and deadly cancers in men worldwide. The surrounding tumor microenvironment (TME) is important in tumor progression, as cytokines and soluble mediators including tumor necrosis factor (TNF-α) or lipocalin-2 (LCN2) can influence tumor growth and formation of metastasis. The exact mechanisms on how these pleiotropic factors affect PCa are still unknown. In this study, we showed for the first time that LCN2 mRNA and protein expression are strongly inducible by TNF-α in the highly metastatic human PCa cell line PC-3. In addition, we observed higher levels of secreted LCN2 in cell culture medium of TNF-α-treated PC-3 cells. We found that different signaling pathways such as p38, NF-κB or JNK were activated shortly after TNF-α treatment. Moreover, the mRNA levels of IL-1β and IL-8 were also significantly increased after 24 h stimulation. Mechanistically, the NF-κB pathway and the JNK signaling axis are directly responsible for LCN2 upregulation. This was shown by the fact that pretreatment with the JNK inhibitors SP600125 or JNK-IN-8 strongly downregulated phosphorylation of c-Jun protein and markedly reduced TNF-α-mediated LCN2 upregulation in PC-3 cells. Likewise, the NF-κB inhibitor QNZ was able to repress TNF-α-induced LCN2 expression in PC-3 cells. Taking into consideration that LCN2 has been described as a tumor promoting factor in PCa, our results indicate that JNK regulates LCN2 expression and unmasks the JNK signaling axis as a possible therapeutic target for patients with PCa.

Rejuvenation of three germ layers tissues by exchanging old blood plasma with saline-albumin

Heterochronic blood sharing rejuvenates old tissues, and most of the studies on how this works focus on young plasma, its fractions, and a few youthful systemic candidates. However, it was not formally established that young blood is necessary for this multi-tissue rejuvenation. Here, using our recently developed small animal blood exchange process, we replaced half of the plasma in mice with saline containing 5% albumin (terming it a "neutral" age blood exchange, NBE) thus diluting the plasma factors and replenishing the albumin that would be diminished if only saline was used. Our data demonstrate that a single NBE suffices to meet or exceed the rejuvenative effects of enhancing muscle repair, reducing liver adiposity and fibrosis, and increasing hippocampal neurogenesis in old mice, all the key outcomes seen after blood heterochronicity. Comparative proteomic analysis on serum from NBE, and from a similar human clinical procedure of therapeutic plasma exchange (TPE), revealed a molecular re-setting of the systemic signaling milieu, interestingly, elevating the levels of some proteins, which broadly coordinate tissue maintenance and repair and promote immune responses. Moreover, a single TPE yielded functional blood rejuvenation, abrogating the typical old serum inhibition of progenitor cell proliferation. Ectopically added albumin does not seem to be the sole determinant of such rejuvenation, and levels of albumin do not decrease with age nor are increased by NBE/TPE. A model of action (supported by a large body of published data) is that significant dilution of autoregulatory proteins that crosstalk to multiple signaling pathways (with their own feedback loops) would, through changes in gene expression, have long-lasting molecular and functional effects that are consistent with our observations. This work improves our understanding of the systemic paradigms of multi-tissue rejuvenation and suggest a novel and immediate use of the FDA approved TPE for improving the health and resilience of older people.

Platelet Transforming Growth Factor-β1 Induces Liver Sinusoidal Endothelial Cells to Secrete Interleukin-6

The roles and interactions of platelets and liver sinusoidal endothelial cells in liver regeneration are unclear, and the trigger that initiates hepatocyte proliferation is unknown. We aimed to identify the key factors released by activated platelets that induce liver sinusoidal endothelial cells to produce interleukin-6 (IL-6), a cytokine implicated in the early phase of liver regeneration. We characterized the releasate of activated platelets inducing the in vitro production of IL-6 by mouse liver sinusoidal endothelial cells and observed that the stimulating factor was a thermolabile protein. Following gel filtration, a single fraction of activated platelet releasate induced a maximal IL-6 secretion by liver sinusoidal endothelial cells (90.2 ± 13.9 versus control with buffer, 9.0 ± 0.8 pg/mL, p < 0.05). Mass spectroscopy analysis of this fraction, followed by in silico processing, resulted in a reduced list of 18 candidates. Several proteins from the list were tested, and only recombinant transforming growth factor β1 (TGF-β1) resulted in an increased IL-6 production up to 242.7 ± 30.5 pg/mL, which was comparable to non-fractionated platelet releasate effect. Using neutralizing anti-TGF-β1 antibody or a TGF-β1 receptor inhibitor, IL-6 production by liver sinusoidal endothelial cells was dramatically reduced. These results support a role of platelet TGF-β1 β1 in the priming phase of liver regeneration.

Antiprolactinoma Effect of Hordenine by Inhibiting MAPK Signaling Pathway Activation in Rats

Prolactinomas are harmful to human health, and the clinical first-line treatment drug is bromocriptine. However, 20% prolactinomas patients did not respond to bromocriptine. Hordenine is an alkaloid separated from Fructus Hordei Germinatus, which showed significant antihyperprolactinemia activity in rats. The aim of this study was to explore the effect and mechanism of hordenine on prolactinomas in rats. The study used estradiol to induce prolactinomas, which caused the activation of the pituitary mitogen-activated protein kinase (MAPK) pathway in rats significantly. The treatment of hordenine restored estradiol, induced the overgrowth of pituitary gland, and reduced the prolactin (PRL) accumulation in the serum and pituitary gland of rats by blocking the MAPK (p38, ERK1/2, and JNK) activation and production of inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). The antiprolactinoma effect of hordenine was mediated by inhibiting the MAPK signaling pathway activation in rats.

Endocrinotherapy resistance of prostate and breast cancer: Importance of the NF‑κB pathway (Review)

Prostate cancer (PCa) and breast cancer (BCa) are two common sex hormone‑related cancer types with high rates of morbidity, and are leading causes of cancer death globally in men and women, respectively. The biological function of androgen or estrogen is a key factor for PCa or BCa tumorigenesis, respectively. Nevertheless, after hormone deprivation therapy, the majority of patients ultimately develop hormone‑independent malignancies that are resistant to endocrinotherapy. It is widely recognized, therefore, that understanding of the mechanisms underlying the process from hormone dependence towards hormone independence is critical to discover molecular targets for the control of advanced PCa and BCa. This review aimed to dissect the important mechanisms involved in the therapeutic resistance of PCa and BCa. It was concluded that activation of the NF‑κB pathway is an important common mechanism for metastasis and therapeutic resistance of the two types of cancer; in particular, the RelB‑activated noncanonical NF‑κB pathway appears to be able to lengthen and strengthen NF‑κB activity, which has been a focus of recent investigations.

Nodal promotes the malignancy of non-small cell lung cancer (NSCLC) cells via activation of NF-κB/IL-6 signals

Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer deaths worldwide. Understanding the mechanisms responsible for the malignancy of NSCLC cells is important for therapy and drug development. Nodal, an important embryonic morphogen, has been reported to modulate tumorigenesis. We found that Nodal can trigger the proliferation of NSCLC cells and decrease the sensitivity to doxorubicin (Dox) and cisplatin (CDDP) treatment. Targeted inhibition of Nodal can suppress the proliferation of NSCLC cells. Among the measured cytokines, Nodal can increase the expression of interleukin-6 (IL-6) and vascular endothelial growth factor A (VEGFA) in NSCLC cells. Inhibition of IL-6, while not VEGFA, attenuated Nodal induced cell proliferation, suggesting the essential roles of IL-6 in Nodal induced malignancy of NSCLC cells. Nodal can trigger the phosphorylation, nuclear translocation and transcriptional activities of p65, the key signal transducer of NF-κB. This was due to the fact that Nodal can increase the phosphorylation of IKKβ/IκBα. The inhibitor of IKKβ abolished Nodal induced activation of p65 and expression of IL-6. Collectively, we found that Nodal can increase the proliferation and decrease chemosensitivity of NSCLC cells via regulation of NF-κB/IL-6 signals. It indicated that Nodal might be a potential therapeutic target for NSCLC treatment.

Human Skin Keratinocytes on Sustained TGF-β Stimulation Reveal Partial EMT Features and Weaken Growth Arrest Responses

Defects in wound closure can be related to the failure of keratinocytes to re-epithelize. Potential mechanisms driving this impairment comprise unbalanced cytokine signaling, including Transforming Growth Factor-β (TFG-β). Although the etiologies of chronic wound development are known, the relevant molecular events are poorly understood. This lack of insight is a consequence of ethical issues, which limit the available evidence to humans. In this work, we have used an in vitro model validated for the study of epidermal physiology and function, the HaCaT cells to provide a description of the impact of sustained exposure to TGF-β. Long term TGF-β1 treatment led to evident changes, HaCaT cells became spindle-shaped and increased in size. This phenotype change involved conformational re-arrangements for actin filaments and E-Cadherin cell-adhesion structures. Surprisingly, the signs of consolidated epithelial-to-mesenchymal transition were absent. At the molecular level, modified gene expression and altered protein contents were found. Non-canonical TGF-β pathway elements did not show relevant changes. However, R-Smads experienced alterations best characterized by decreased Smad3 levels. Functionally, HaCaT cells exposed to TGF-β1 for long periods showed cell-cycle arrest. Yet, the strength of this restraint weakens the longer the treatment, as revealed when challenged by pro-mitogenic factors. The proposed setting might offer a useful framework for future research on the mechanisms driving wound chronification.

RAS/MAPK signaling functions in oxidative stress, DNA damage response and cancer progression

Mitogen-activated protein kinase (MAPK) signaling pathways organize a great constitution network that regulates several physiological processes, like cell growth, differentiation, and apoptotic cell death. Due to the crucial importance of this signaling pathway, dysregulation of the MAPK signaling cascades is involved in the pathogenesis of various human cancer types. Oxidative stress and DNA damage are two important factors which in common lead to carcinogenesis through dysregulation of this signaling pathway. Reactive oxygen species (ROS) are a common subproduct of oxidative energy metabolism and are considered to be a significant physiological modulator of several intracellular signaling pathways including the MAPK pathway. Studies demonstrated that the MAP kinases extracellular signal-regulated kinase (ERK) 1/2 and p38 were activated in response to oxidative stress. In addition, DNA damage is a partly common circumstance in cell life and may result in mutation, cancer, and even cell death. Recently, accumulating evidence illustrated that the MEK/ERK pathway is associated with the suitable performance of cellular DNA damage response (DDR), the main pathway of tumor suppression. During DDR, the MEK/ERK pathway is regularly activated, which contributes to the appropriate activation of DDR checkpoints to inhibit cell division. Therefore, the aim of this review is to comprehensively discuss the critical function of MAPK signaling in oxidative stress, DNA damage, and cancer progression.

Current Knowledge of the Potential Links between Inflammation and Prostate Cancer

Inflammation is inherent in prostatic diseases and it is now accepted that it may facilitate cellular proliferation in both benign and malignant conditions. The strong relationship between prostatic inflammation and pathogenesis of benign prostatic hyperplasia (BPH) is supported by epidemiologic, histopathologic and molecular evidence. Contrariwise, the role of inflammation in prostate carcinogenesis is still controversial, although current data indicate that the inflammatory microenvironment can regulate prostate cancer (PCa) growth and progression. Knowledge of the complex molecular landscape associated with chronic inflammation in the context of PCa may lead to the introduction and optimization of novel targeted therapies. In this perspective, evaluation of the inflammatory component in prostate specimens could be included in routine pathology reports.

NF-κB signaling and crosstalk during carcinogenesis

Transcription factors (TFs) are proteins that control the transcription of genetic information from DNA to mRNA by binding to specific DNA sequences either on their own or with other proteins as a complex. TFs thus support or suppress the recruitment of the corresponding RNA polymerase. In general, TFs are classified by structure or function. The TF, Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), is expressed in all cell types and tissues. NF-κB signaling and crosstalk are involved in several steps of carcinogenesis including in sequences involving pathogenic stimulus, chronic inflammation, fibrosis, establishment of its remodeling to the precancerous niche (PCN) and transition of a normal cell to a cancer cell. Triggered by various inflammatory cytokines, NF-κB is activated along with other TFs with subsequent stimulation of cell proliferation and inhibition of apoptosis. The involvement of NF-κB in carcinogenesis provides an opportunity to develop anti-NF-κB therapies. The complexity of these interactions requires that we elucidate those aspects of NF-κB interactions that play a role in carcinogenesis, the sequence of events leading to cancer.

Reduced FRG1 expression promotes prostate cancer progression and affects prostate cancer cell migration and invasion

BACKGROUND

Prostate cancer is the most common form of cancer in males and accounts for high cancer related deaths. Therapeutic advancement in prostate cancer has not been able to reduce the mortality burden of prostate cancer, which warrants further research. FRG1 which affects angiogenesis and cell migration in Xenopus, can be a potential player in tumorigenesis. In this study, we investigated the role of FRG1 in prostate cancer progression.

METHODS

Immunohistochemistry was performed to determine FRG1 expression in patient samples. FRG1 expression perturbation was done to investigate the effect of FRG1 on cell proliferation, migration and invasion, in DU145, PC3 and LNCaP cells. To understand the mechanism, we checked expression of various cytokines and MMPs by q-RT PCR, signaling molecules by western blot, in FRG1 perturbation sets. Results were validated by use of pharmacological inhibitor and activator and, western blot.

RESULTS

In prostate cancer tissue, FRG1 levels were significantly reduced, compared to the uninvolved counterpart. FRG1 expression showed variable effect on PC3 and DU145 cell proliferation. FRG1 levels consistently affected cell migration and invasion, in both DU145 and PC3 cells. Ectopic expression of FRG1 led to significant reduction in cell migration and invasion in both DU145 and PC3 cells, reverse trends were observed with FRG1 knockdown. In androgen receptor positive cell line LNCaP, FRG1 doesn't affect any of the cell properties. FRG1 knockdown led to significantly enhanced expression of GM-CSF, MMP1, PDGFA and CXCL1, in PC3 cells and, in DU145, it led to higher expression of GM-CSF, MMP1 and PLGF. Interestingly, FRG1 knockdown in both the cell lines led to activation of p38 MAPK. Pharmacological activation of p38 MAPK led to increase in the expression of GM-CSF and PLGF in DU145 whereas in PC3 it led to enhanced expression of GM-CSF, MMP1 and CXCL1. On the other hand, inhibition of p38 MAPK led to reduction in the expression of above mentioned cytokines.

CONCLUSION

FRG1 expression is reduced in prostate adenocarcinoma tissue. FRG1 expression affects migration and invasion in AR negative prostate cancer cells through known MMPs and cytokines, which may be mediated primarily via p38 MAPK activation.

TGF-β1 protects colon tumor cells from apoptosis through XAF1 suppression

Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine that functions as a growth suppressor in normal epithelial cells and early stage tumors, but acts as a tumor promoter during malignant progression. However, the molecular basis underlying the conversion of TGF‑β1 function remains largely undefined. X‑linked inhibitor of apoptosis‑associated factor 1 (XAF1) is a pro‑apoptotic tumor suppressor that frequently displays epigenetic inactivation in various types of human malignancies, including colorectal cancer. The present study explored whether the anti‑apoptotic effect of TGF‑β1 is linked to its regulatory effect on XAF1 induction in human colon cancer cells under stressful conditions. The results revealed that TGF‑β1 treatment protected tumor cells from various apoptotic stresses, including 5‑fluorouracil, etoposide and γ‑irradiation. XAF1 expression was activated at the transcriptional level by these apoptotic stresses and TGF‑β1 blocked the stress‑mediated activation of the XAF1 promoter. The study also demonstrated that mitogen‑activated protein kinase kinase inhibition or extracellular signal‑activated kinase (Erk)1/2 depletion induced XAF1 induction, while the activation of K‑Ras (G12C) led to its reduction. In addition, TGF‑β1 blocked the stress‑mediated XAF1 promoter activation and induction of apoptosis. This effect was abrogated if Erk1/2 was depleted, indicating that TGF‑β1 represses XAF1 transcription through Erk activation, thereby protecting tumor cells from apoptotic stresses. These findings point to a novel molecular mechanism underlying the tumor‑promoting function of TGF‑β1, which may be utilized in the development of a novel therapeutic strategy for the treatment of colorectal cancer.

A review on the interactions between the tumor microenvironment and androgen receptor signaling in prostate cancer

Prostate cancer growth is controlled by androgen receptor signaling via both androgen-dependent and androgen-independent pathways. Furthermore, the prostate is an immune competent organ with inflammatory changes both within the systemic and local environment contributing to the reprogramming of the prostatic epithelium with consistently elevated lymphocyte infiltration and proinflammatory cytokines being found in prostate cancer. The crosstalk between the tumor microenvironment and androgen receptor signaling is complex with both protumorigenic and antitumorigenic roles observed. However, despite an increase in immune checkpoint inhibitors and inflammatory signaling blockades available for a range of cancer types, we are yet to see substantial progress in the treatment of prostate cancer. Therefore, this review aims to summarize the tumor microenvironment and its impact on androgen receptor signaling in prostate cancer.

The Anti-Inflammatory Effects of Vitamin D in Tumorigenesis

In conjunction with the classical functions of regulating intestinal, bone, and kidney calcium and phosphorus absorption, as well as bone mineralization of vitamin D, the population-based association between low vitamin D status and increased cancer risk is now generally accepted. Inflammation is causally related to oncogenesis. It is widely thought that vitamin D plays an important role in the modulation of the inflammation system by regulating the production of inflammatory cytokines and immune cells, which are crucial for the pathogenesis of many immune-related diseases. Mechanistic studies have shown that vitamin D influences inflammatory processes involved in cancer progression, including cytokines, prostaglandins, MAP kinase phosphatase 5 (MKP5), the nuclear factor kappa B (NF-κB) pathway, and immune cells. Multiple studies have shown that vitamin D has the potential to inhibit tumor development by interfering with the inflammation system. The present review summarizes recent studies of the mechanisms of vitamin D on regulating the inflammation system, which contributes to its potential for cancer prevention and therapy. This review helps answer whether inflammation mediates a causal relationship between vitamin D and tumorigenesis.

Delphinidin induces apoptosis and inhibits epithelial-to-mesenchymal transition via the ERK/p38 MAPK-signaling pathway in human osteosarcoma cell lines

Delphinidin is major anthocyanidin that is extracted from many pigmented fruits and vegetables. This substance has anti-oxidant, anti-inflammatory, anti-angiogenic, and anti-cancer properties. In addition, delphinidin strongly suppresses the migration and invasion of various cancer cells during tumorigenesis. Although delphinidin has anti-cancer effects, little is known about its functional roles in osteosarcoma (OS). For these reasons, we have demonstrated the effects of delphinidin on OS cell lines. The effects of delphinidin on cell viability and growth of OS cells were assessed using the MTT assay and colony formation assays. Hoechst staining indicated that the delphinidin-treated OS cells were undergoing apoptosis. Flow cytometry, confocal microscopy, and a western blot analysis also indicated evidence of apoptosis. Inhibition of cell migration and invasion was found to be associated with epithelial-to-mesenchymal transition (EMT), observed by using a wound healing assay, an invasion assay, and a western blot analysis. Furthermore, delphinidin treatment resulted in a profound reduction of phosphorylated forms of ERK and p38. These findings demonstrate that delphinidin treatment suppressed EMT through the mitogen-activated protein kinase (MAPK) signaling pathway in OS cell lines. Taken together, our results suggest that delphinidin strongly inhibits cell proliferation and induces apoptosis. Delphinidin treatment also suppresses cell migration and prevents EMT via the MAPK-signaling pathway in OS cell lines. For these reasons, delphinidin has anti-cancer effects and can suppress metastasis in OS cell lines, and it might be worth using as an OS therapeutic agent.

Stemness and chemoresistance are imparted to the OC cells through TGFβ1 driven EMT

Ovarian cancer (OC) is the fourth most common gynecological malignancy due to its highly aggressive, recurrent, and drug-resistant nature. The last two features are rendered by the presence of cancer stem cells (CSCs). Factors like TGFβ1 and their downstream signaling pathways are upregulated in most cancers and are known to induce EMT and stemness, but the exact mechanisms underlying the process remain unelucidated. In our study, TGFβ1 induced enhanced stem-like properties like high expression of the pluripotent markers SOX2, OCT4a, and NANOG, along with CD44, and CD117 in the OC cells. In addition, increased activity of the aldehyde dehydrogenase enzyme, formation of compact spheroids, and a quiescent phenotype were observed. In deciphering the mechanism behind it, our data propose ZEB1 transcription factor to play a substantial role in inducing the EMT-mediated stemness and chemoresistance. Further, in our study, we elucidated the significant contribution of both Smad and non-Smad pathways like ERK, JNK, and P38 MAPK pathways in the induction of stem-like characteristics. The novelty of the study also resides with the fact in the expression of different lineage-specific markers, like CD31, CD45, and CD117 along with CD44 in the TGFβ1-induced epithelial ovarian cancer spheroids. This suggests a tendency of the spheroidal cells towards differentiating into heterogenic populations, which is a distinctive feature of a stem cell. Taken together, the present study provides an insight to the molecular cues involved in the acquisition of stemness and chemoresistance along with tumor heterogeneity in TGFβ1-induced OC cells.

PSCA regulates IL-6 expression through p38/NF-κB signaling in prostate cancer

BACKGROUND

Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol (GPI)-anchored cell surface protein. We previously reported that PSCA involved in proliferation and invasion of PCa cells, however, the underlying mechanisms are unknown. In this study, we aimed to explore the regulating role of PSCA gene expression in interleukin-6 (IL-6) autocrine of PCa cells.

METHODS

The stable knockdown-PSCA and ectopically overexpressed-PSCA vector were constructed and transfected into human PCa DU145 and PC-3M cells. The effects of PSCA overexpression or knockdown were determined in proliferation, invasion, and metastasis assays. The effect of PSCA on the expression and secretion of IL-6 was evaluated by immunoblotting and ELISA. Subcellular localization and expression pattern of PSCA and IL-6 protein were examined by immunohistochemistry. Its clinical significance was statistically analyzed.

RESULTS

The results showed that stable knockdown of PSCA delayed proliferation, migration, and invasion while overexpressing PSCA enhanced the proliferation, migration, and invasion in vitro and the lung metastasis in vivo of PCa cells. Importantly, the PSCA involved in the IL-6 secretion and positively regulated p38/NF-κB/IL-6 signaling, leading to enhanced PCa cell invasion and metastasis. Both the expression of PSCA and IL-6 were significantly associated with poor biochemical recurrence-free survival of patients with PCa. PSCA protein expression showed a prognostic value in overall survival as indicated by Kaplan-Meier analysis.

CONCLUSIONS

These results indicate that PSCA regulates the expression and secretion of IL-6 in human PCa cells through p38/NF-κB signaling pathways. PSCA may be a potential diagnostic marker and therapeutic target for PSCA-positive PCa.

Fibroblast Growth Factor 2 as an Antifibrotic: Antagonism of Myofibroblast Differentiation and Suppression of Pro-Fibrotic Gene Expression

Fibrosis is a pathological condition that is characterized by the replacement of dead or damaged tissue with a nonfunctional, mechanically aberrant scar, and fibrotic pathologies account for nearly half of all deaths worldwide. The causes of fibrosis differ somewhat from tissue to tissue and pathology to pathology, but in general some of the cellular and molecular mechanisms remain constant regardless of the specific pathology in question. One of the common mechanisms underlying fibroses is the paradigm of the activated fibroblast, termed the "myofibroblast," a differentiated mesenchymal cell with demonstrated contractile activity and a high rate of collagen deposition. Fibroblast growth factor 2 (FGF2), one of the members of the mammalian fibroblast growth factor family, is a cytokine with demonstrated antifibrotic activity in non-human animal, human, and in vitro models. FGF2 is highly pleiotropic and its receptors are present on many different cell types throughout the body, lending a great deal of variety to the potential mechanisms of FGF2 effects on fibrosis. However, recent reports demonstrate that a substantial contribution to the antifibrotic effects of FGF2 comes from the inhibitory effects of FGF2 on connective tissue fibroblasts, activated myofibroblasts, and myofibroblast progenitors. FGF2 demonstrates effects antagonistic towards fibroblast activation and towards mesenchymal transition of potential myofibroblast-forming cells, as well as promotes a gene expression paradigm more reminiscent of regenerative healing, such as that which occurs in the fetal wound healing response, than fibrotic resolution. With a better understanding of the mechanisms by which FGF2 alters the wound healing cascade and results in a shift away from scar formation and towards functional tissue regeneration, we may be able to further address the critical need of therapy for varied fibrotic pathologies across myriad tissue types.

Establishment of in vitro model of corneal scar pathophysiology

Corneal scarring is the major source of permanent blindness worldwide. The complex pathophysiology of corneal scarring is not comprehensibly understood as it involves the interaction of a constellation of pro-fibrotic cytokines influencing several signaling pathways involved in corneal scar development. In the present study, an attempt has been made to generate a relatively simple in vitro corneal scar model using primary corneal keratocytes by exogenously providing an optimized dose of combination of cytokines (TGF-β1, IL-6, and IL-8) involved in scar formation in situ. Data obtained from gene and protein expression analysis depicted enhanced ECM production with discrete expression of myofibroblast specific markers. The protein-protein interactions associated these proteins to various pathways involved in wound healing, cellular migration, and cytoskeletal remodeling justifying high relevance to in vivo scar formation. Hence the developed model can be used to acquire understanding about corneal scar pathophysiology and thus might be useful for designing the treatment modalities and efficacies for controlling scar formation.

Radiation-induced Epstein-Barr virus reactivation in gastric cancer cells with latent EBV infection

Epstein-Barr virus, a ubiquitous human herpes virus with oncogenic activity, can be found in 6%-16% of gastric carcinomas worldwide. In Epstein-Barr virus-associated gastric carcinoma, only a few latent genes of the virus are expressed. Ionizing irradiation was shown to induce lytic Epstein-Barr virus infection in lymphoblastoid cell lines with latent Epstein-Barr virus infection. In this study, we examined the effect of ionizing radiation on the Epstein-Barr virus reactivation in a gastric epithelial cancer cell line (SNU-719, an Epstein-Barr virus-associated gastric carcinoma cell line). Irradiation with X-ray (dose = 5 and 10 Gy; dose rate = 0.5398 Gy/min) killed approximately 25% and 50% of cultured SNU-719 cells, respectively, in 48 h. Ionizing radiation increased the messenger RNA expression of immediate early Epstein-Barr virus lytic genes (BZLF1 and BRLF1), determined by real-time reverse transcription polymerase chain reaction, in a dose-dependent manner at 48 h and, to a slightly lesser extent, at 72 h after irradiation. Similar findings were observed for other Epstein-Barr virus lytic genes (BMRF1, BLLF1, and BcLF1). After radiation, the expression of transforming growth factor beta 1 messenger RNA increased and reached a peak in 12-24 h, and the high-level expression of the Epstein-Barr virus immediate early genes can convert latent Epstein-Barr virus infection into the lytic form and result in the release of infectious Epstein-Barr virus. To conclude, Ionizing radiation activates lytic Epstein-Barr virus gene expression in the SNU-719 cell line mainly through nuclear factor kappaB activation. We made a brief review of literature to explore underlying mechanism involved in transforming growth factor beta-induced Epstein-Barr virus reactivation. A possible involvement of nuclear factor kappaB was hypothesized.

Inflammation and Epithelial-Mesenchymal Transition in Pancreatic Ductal Adenocarcinoma: Fighting Against Multiple Opponents

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and one of the most lethal human cancers. Inflammation is a critical component in PDAC initiation and progression. Inflammation also contributes to the aggressiveness of PDAC indirectly via induction of epithelial-mesenchymal transition (EMT), altogether leading to enhanced resistance to chemotherapy and poor survival rates. This review gives an overview of the key pro-inflammatory signaling pathways involved in PDAC pathogenesis and discusses the role of inflammation in induction of EMT and development of chemoresistance in patients with PDAC.

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.

Functional analysis of keratinocyte and fibroblast gene expression in skin and keloid scar tissue based on deviation analysis of dynamic capabilities

The aim of the present study was to select key genes that are associated with fibroblasts and keratinocytes during keloid scar progression and development. The gene expression profile of GSE44270, which includes 32 samples, was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) in case samples compared with control samples were screened using the Limma R package followed by hierarchical clustering analysis. Protein-protein interaction (PPI) networks of the total selected DEGs were constructed using Cytoscape. Moreover, the Gene Ontology biological processes and significant Kyoto Encyclopedia of Genes and Genomes pathways of the total selected DEGs were enriched using the Database for Annotation, Visualization and Integrated Discovery. Significant pathways that may be associated with keloid scar were analyzed using deviation analysis of dynamic capabilities. There were 658 DEGs in fibroblast keloid vs. normal, 112 DEGs in fibroblast non-lesion vs. normal, 439 DEGs in fibroblast keloid vs. non-lesion, 523 DEGs in keratocyte keloid vs. normal, 186 DEGs in keratocyte non-lesion vs. normal, and 963 DEGs in keratocyte keloid vs. non-lesion groups. HOXA9, BMP4, CDKN1A and SMAD2 in fibroblasts, and HOXA7, MCM8, PSMA4 and PSMB2 in keratinocytes were key genes in the PPI networks. Moreover, the amino sugar and nucleotide sugar metabolism pathway, cell cycle, and extracellular matrix (ECM)-receptor interaction pathway were significant pathways. This study suggests that several key genes (BMP4, HOXA9, SMAD2, CDKN1A, HOXA7, PSMA4 and PSMB2) that participate in some significant pathways (cell cycle and ECM-receptor interaction pathways) may be potential therapeutic targets for keloid scars.

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.

Mechanism of Cyclosporine-induced Overgrowth in Gingiva

Cyclosporine A (CsA) is a widely used immunosuppressant but with significant side-effects, such as gingival overgrowth. This study investigates how CsA induces gingival proliferation and shows the effects of the CsA-associated signaling messengers, IL-6 and TGF-β1, on gingival proliferation. CsA increased both IL-6 and TGF-β1 levels. In addition to CsA, an IL-6 or TGF-β1 treatment also induced gingival fibroblast proliferation. Inhibiting the cytokine resulted in the suppression of CsA-induced proliferation. MAPKs and PI3K are known to be involved in cell proliferation. Therefore, the effect of CsA on the kinase activities was examined. The results showed that both p38 MAPK and PI3K are essential for gingival fibroblast proliferation. TGF-β1 and IL-6 and their associated signaling transduction may be novel bona fide molecular targets for the prevention of gingival overgrowth in CsA-treated patients. (Abbreviations: MAPK, mitogen-activated protein kinase; PI3K, phosphatidylinositol 3-kinase.)

Tumor-Activated Mesenchymal Stromal Cells Promote Osteosarcoma Stemness and Migratory Potential via IL-6 Secretion

Osteosarcoma (OS) is an aggressive bone malignancy with a high relapse rate despite combined treatment with surgery and multiagent chemotherapy. As for other cancers, OS-associated microenvironment may contribute to tumor initiation, growth, and metastasis. We consider mesenchymal stromal cells (MSC) as a relevant cellular component of OS microenvironment, and have previously found that the interaction between MSC and tumor cells is bidirectional: tumor cells can modulate their peripheral environment that in turn becomes more favorable to tumor growth through metabolic reprogramming. Here, we determined the effects of MSC on OS stemness and migration, two major features associated with recurrence and chemoresistance. The presence of stromal cells enhanced the number of floating spheres enriched in cancer stem cells (CSC) of the OS cell population. Furthermore, the co-culturing with MSC stimulated the migratory capacity of OS via TGFβ1 and IL-6 secretion, and the neutralizing antibody anti-IL-6 impaired this effect. Thus, stromal cells in combination with OS spheres exploit a vicious cycle where the presence of CSC stimulates mesenchymal cytokine secretion, which in turn increases stemness, proliferation, migration, and metastatic potential of CSC, also through the increase of expression of adhesion molecules like ICAM-1. Altogether, our data corroborate the concept that a comprehensive knowledge of the interplay between tumor and stroma that also includes the stem-like fraction of tumor cells is needed to develop novel and effective anti-cancer therapies.

Targeted gene silencing of CCL2 inhibits triple negative breast cancer progression by blocking cancer stem cell renewal and M2 macrophage recruitment

Triple negative breast cancers are an aggressive subtype of breast cancer, characterized by the lack of estrogen receptor, progesterone receptor and Her2 expression. Triple negative breast cancers are non-responsive to conventional anti-hormonal and Her2 targeted therapies, making it necessary to identify new molecular targets for therapy. The chemokine CCL2 is overexpressed in invasive breast cancers, and regulates breast cancer progression through multiple mechanisms. With few approaches to target CCL2 activity, its value as a therapeutic target is unclear. In these studies, we developed a novel gene silencing approach that involves complexing siRNAs to TAT cell penetrating peptides (Ca-TAT) through non-covalent calcium cross-linking. Ca-TAT/siRNA complexes penetrated 3D collagen cultures of breast cancer cells and inhibited CCL2 expression more effectively than conventional antibody neutralization. Ca-TAT/siRNA complexes targeting CCL2 were delivered to mice bearing MDA-MB-231 breast tumor xenografts. In vivo CCL2 gene silencing inhibited primary tumor growth and metastasis, associated with a reduction in cancer stem cell renewal and recruitment of M2 macrophages. These studies are the first to demonstrate that targeting CCL2 expression in vivo may be a viable therapeutic approach to treating triple negative breast cancer.

Phosphorylated-p38 mitogen-activated protein kinase expression is associated with clinical factors in invasive breast cancer

Purpose

P38 mitogen-activated protein kinases (MAPK) level is an important prognostic factor in breast cancer. This study was performed to detect the expressions of P-p38 MAPK expression in breast cancer and explore their correlations with clinicopathological factors.

Experimental design

Tumor samples from 355 Chinese patients diagnosed with invasive breast cancer and adjacent non-cancerous tissue were collected between 2003 and 2010. The expression of P-p38 MAPK was analyzed using immunohistochemical staining. The correlations between P-p38 MAPK expression and clinicopathological findings including age, AJCC Stage, Histologic characters, ER, PR, and HER2 were analyzed using the parametric correlation method. P-p38 MAPK was selected as dependent variable to perform multivariate analysis respectively at last.

Results

Overall, 161 (45 %) and 183 (52 %) of the 355 specimens showed positive P-p38 MAPK staining in the cytoplasm and nucleus respectively, which were significant higher than that in the adjacent non-cancerous tissues in both the cytoplasm and the nucleus. High P-p38 MAPK expression of cytoplasm and nucleus were both associated with positive PR status in luminal A/B type of breast cancer, and were both associated with positive HER2 status in HER2-positive type of breast cancer. The result of multivariate analysis demonstrated that HER2 and PR were both significantly association with P-p38 MAPK expression of cytoplasm and nucleus.

Conclusions

Our study suggests that P-p38 MAPK expression were significantly associated with clinicopathological factors and PR/HER2 might association with phosphorylation of p38 MAPK in different types of breast cancer.

JunD Is Required for Proliferation of Prostate Cancer Cells and Plays a Role in Transforming Growth Factor-β (TGF-β)-induced Inhibition of Cell Proliferation

TGF-β inhibits proliferation of prostate epithelial cells. However, prostate cancer cells in advanced stages become resistant to inhibitory effects of TGF-β. The intracellular signaling mechanisms involved in differential effects of TGF-β during different stages are largely unknown. Using cell line models, we have shown that TGF-β inhibits proliferation in normal (RWPE-1) and prostate cancer (DU145) cells but does not have any effect on proliferation of prostate cancer (PC3) cells. We have investigated the role of Jun family proteins (c-Jun, JunB, and JunD) in TGF-β effects on cell proliferation. Jun family members were expressed at different levels and responded differentially to TGF-β treatment. TGF-β effects on JunD protein levels, but not mRNA levels, correlated with its effects on cell proliferation. TGF-β induced significant reduction in JunD protein in RWPE-1 and DU145 cells but not in PC3 cells. Selective knockdown of JunD expression using siRNA in DU145 and PC3 cells resulted in significant reduction in cell proliferation, and forced overexpression of JunD increased the proliferation rate. On the other hand, knockdown of c-Jun or JunB had little, if any, effect on cell proliferation; overexpression of c-Jun and JunB decreased the proliferation rate in DU145 cells. Further studies showed that down-regulation of JunD in response to TGF-β treatment is mediated via the proteasomal degradation pathway. In conclusion, we show that specific Jun family members exert differential effects on proliferation in prostate cancer cells in response to TGF-β, and inhibition of cell proliferation by TGF-β requires degradation of JunD protein.

Inhibiting DX2-p14/ARF Interaction Exerts Antitumor Effects in Lung Cancer and Delays Tumor Progression

The aminoacyl tRNA synthetase complex-interacting multifunctional protein 2 (AIMP2) splice variant designated DX2 is induced by cigarette smoke carcinogens and is often detected in human lung cancer specimens. However, the function of DX2 in lung carcinogenesis is obscure. In this study, we found that DX2 expression was induced by oncogenes in human lung cancer tissues and cells. DX2 prevented oncogene-induced apoptosis and senescence and promoted drug resistance by directly binding to and inhibiting p14/ARF. Through chemical screening, we identified SLCB050, a novel compound that blocks the interaction between DX2 and p14/ARF in vitro and in vivo SLCB050 reduced the viability of human lung cancer cells, especially small cell lung cancer cells, in a p14/ARF-dependent manner. Moreover, in a mouse model of K-Ras-driven lung tumorigenesis, ectopic expression of DX2 induced small cell and non-small cell lung cancers, both of which could be suppressed by SLCB050 treatment. Taken together, our findings show how DX2 promotes lung cancer progression and how its activity may be thwarted as a strategy to treat patients with lung cancers exhibiting elevated DX2 levels. Cancer Res; 76(16); 4791-804. ©2016 AACR.