Search Results (6)

Background: The mitogen-activated protein kinase (MAPK) signaling pathway is frequently dysregulated in cutaneous squamous cell carcinoma (cSCC). Tumor progression locus 2 (Tpl2), a serine/threonine protein kinase within the MAPK family, regulates cellular proliferation, survival, and inflammatory responses. Loss of Tpl2 activates compensatory signaling cascades, driving increased papilloma and cSCC development. In this study we examined whether dysregulated ErbB signaling contributes to the enhanced tumor burden found in Tpl2^−/− mice. Methods: To evaluate whether aberrant ErbB signaling drives tumorigenesis in Tpl2^−/− mice, wild-type (Tpl2^+/+) and Tpl2^−/− mice were subjected to a two-stage chemical carcinogenesis protocol for 48 weeks. A subset of mice received Gefitinib (an EGFR inhibitor) or Lapatinib (a HER2 inhibitor) in their diet. Results: We found that Tpl2 ablation increases gene expression of EGFR, HER2, and HER3, while baseline protein levels remain unchanged between Tpl2 genotypes. To investigate the possibility of microRNA (miR)-mediated post-transcriptional regulation of EGFR, HER2, and HER3, we measured ErbB-related miR expression in keratinocytes. We found that HER2/3-related miRs 205 and 21 are increased in Tpl2^−/− keratinocytes. Further, Tpl2 loss enhances p-EGFR, EGFR, and HER2 protein expression in papillomas. and HER2-related microRNAs (miRs) 205 and 21 in keratinocytes, and enhances p-EGFR, EGFR, and HER2 protein expression in papillomas. Tpl2^−/− mice developed 12-fold more papillomas and 4-fold more cSCCs compared to Tpl2^+/+ animals. Treatment with Gefitinib or Lapatinib reduced papilloma numbers by 88% and 50%, respectively, while restoring cSCC numbers to Tpl2^+/+ levels. Conclusions: These findings indicate that ErbB targeting represents a promising therapeutic strategy for cSCCs arising from MAPK pathway dysregulation. Full article

The Nuclear factor erythroid 2-related factor 2 (NRF2) Neurogenic locus NOTCH homolog protein (NOTCH) crosstalk has emerged as a critical regulatory axis in the progression of solid cancers, especially lung, affecting tumor growth and resistance to therapy. NRF2 is a master transcription factor that orchestrates the cellular antioxidant response, while NOTCH signaling is involved in the cell–cell communication processes by influencing the patterns of gene expression and differentiation. Although frequently altered independently, genetic and epigenetic dysregulation of both NRF2 and NOTCH pathways often converge to deregulate oxidative stress responses and promote tumor cell survival. Recent findings reveal that the NRF2/NOTCH interplay extends beyond canonical signaling, contributing to metabolic reprogramming and reshaping the tumor microenvironment (TME) to promote cancer malignancy. Emerging scientific evidences highlight the key role of biochemical and metabolomic changes within NRF2–NOTCH crosstalk, in contributing to cancer progression and metabolic reprogramming, beyond facilitating the adaptation of cancer cells to the TME. Actually, the effects of the NRF2–NOTCH bidirectional interaction in either supporting or suppressing lung tumor phenotypes are still unclear. This review explores the molecular mechanisms underlying NRF2–NOTCH crosstalk in lung cancer, highlighting the impact of genetic and epigenetic deregulation mechanisms on neoplastic processes, modulating the TME and driving the metabolic reprogramming. Furthermore, we discuss therapeutic opportunities for targeting this regulatory network, which may open new avenues for overcoming drug resistance and improving clinical outcomes in lung cancer. Full article

Androgen deprivation therapy (ADT) is a systemic therapy for advanced prostate cancer (PCa). Although most patients initially respond to ADT, almost all cancers eventually develop castration resistance. Castration-resistant PCa (CRPC) is associated with a very poor prognosis, and the treatment of which is a serious clinical challenge. Accumulating evidence suggests that abnormal expression and activation of various kinases are associated with the emergence and maintenance of CRPC. Many efforts have been made to develop small molecule inhibitors to target the key kinases in CRPC. These inhibitors are designed to suppress the kinase activity or interrupt kinase-mediated signal pathways that are associated with PCa androgen-independent (AI) growth and CRPC development. In this review, we briefly summarize the roles of the kinases that are abnormally expressed and/or activated in CRPC and the recent advances in the development of small molecule inhibitors that target kinases for the treatment of CRPC. Full article

Background: The single nucleotide polymorphism (SNP) rs1042058 within the gene locus encoding tumor progression locus 2 (TPL2) has been recently identified as a risk gene for inflammatory bowel disease (IBD). TPL2 has been shown to regulate pro-inflammatory signaling and cytokine secretion, while inhibition of TPL2 decreases intestinal inflammation in vivo. However, the clinical and molecular implications of this disease-associated TPL2 variation in IBD patients have not yet been studied. Methods: We analyzed the impact of the IBD-associated TPL2 variation using clinical data of 2145 genotyped patients from the Swiss IBD Cohort Study (SIBDCS). Furthermore, we assessed the molecular consequences of the TPL2 variation in ulcerative colitis (UC) and Crohn’s disease (CD) patients by real-time PCR and multiplex ELISA of colon biopsies or serum, respectively. Results: We found that presence of the SNP rs1042058 within the TPL2 gene locus results in significantly higher numbers of CD patients suffering from peripheral arthritis. In contrast, UC patients carrying this variant feature a lower risk for intestinal surgery. On a molecular level, the presence of the rs1042058 (GG) IBD-risk polymorphism in TPL2 was associated with decreased mRNA levels of IL-10 in CD patients and decreased levels of IL-18 in the intestine of UC patients. Conclusions: Our data suggest that the presence of the IBD-associated TPL2 variation might indicate a more severe disease course in CD patients. These results reveal a potential therapeutic target and demonstrate the relevance of the IBD-associated TPL2 SNP as a predictive biomarker in IBD. Full article

The cytogenic locus of the WWOX gene overlaps with the second most active fragile site, FRA16D, which is present at a higher frequency in bladder cancer (BLCA) patients with smoking habit, a known risk factor of this tumor. Recently, we demonstrated the relevance of the role of WWOX in grade 2 BLCA in collaboration with two AP-2 transcription factors whose molecular actions supported or opposed pro-cancerous events, suggesting a distinct character. As further research is needed on higher grades, the aim of the present study was to examine WWOX-AP-2 functionality in grade 3 and 4 BLCA using equivalent in vitro methodology with additional transcriptome profiling of cellular variants. WWOX and AP-2α demonstrated similar anti-cancer functionality in most biological processes with subtle differences in MMP-2/9 regulation; this contradicted that of AP-2γ, whose actions potentiated cancer progression. Simultaneous overexpression of WWOX and AP-2α/AP-2γ revealed that single discrepancies appear in WWOX-AP-2α collaboration but only at the highest BLCA grade; WWOX-AP-2α collaboration was considered anti-cancer. However, WWOX only appeared to have residual activity against oncogenic AP-2γ in grade 3 and 4: variants with either AP-2γ overexpression alone or combined WWOX and AP-2γ overexpression demonstrated similar pro-tumoral behavior. Transcriptome profiling with further gene ontology certified biological processes investigated in vitro and indicated groups of genes consisting of AP-2 targets and molecules worth investigation as biomarkers. In conclusion, tumor suppressor synergism between WWOX and AP-2α is unimpaired in high-grade BLCA compared to intermediate grade, yet the ability of WWOX to guide oncogenic AP-2γ is almost completely lost. Full article

Tumor progression locus 2 (Tpl2) is a mitogen-activated protein kinase (MAPK) kinase kinase (MAP3K) that conveys various intra- and extra-cellular stimuli to effector proteins of cells provoking adequate adoptive responses. Recent studies have elucidated that Tpl2 is an indispensable signal transducer as an MAP3K family member in diverse signaling pathways that regulate cell proliferation, survival, and death. Since tumorigenesis results from dysregulation of cellular proliferation, differentiation, and apoptosis, Tpl2 participates in many decisive molecular processes of tumor development and progression. Moreover, Tpl2 is closely associated with cytokine release of inflammatory cells, which has crucial effects on not only tumor cells but also tumor microenvironments. These critical roles of Tpl2 in human cancers make it an attractive anti-cancer therapeutic target. However, Tpl2 contradictorily works as a tumor suppressor in some cancers. The double-sided effects of Tpl2 originate from the specific upstream and downstream signaling environment of each tumor, since Tpl2 interacts with various signaling components. This review summarizes recent studies concerning the possible roles of Tpl2 in human cancers and considers its possibility as a therapeutic target, against which novel anti-cancer agents could be developed. Full article