p120-catenin suppresses proliferation and tumor growth of oral squamous cell carcinoma via inhibiting nuclear phospholipase C-γ1 signaling

Cetuximab chemotherapy resistance: Insight into the homeostatic evolution of head and neck cancer (Review)

The complex evolution of genetic alterations in cancer that occurs in vivo is a selective process involving numerous factors and mechanisms. Chemotherapeutic agents that prevent the growth and spread of cancer cells induce selective pressure, leading to rapid artificial selection of resistant subclones. This rapid evolution is possible because antineoplastic drugs promote alterations in tumor‑cell metabolism, thus creating a bottleneck event. The few resistant cells that survive in this new environment obtain differential reproductive success that enables them to pass down the newly selected resistant gene pool. The present review aims to summarize key findings of tumor evolution, epithelial‑mesenchymal transition and resistance to cetuximab therapy in head and neck squamous cell carcinoma.

Nuclear Phospholipids and Signaling: An Update of the Story

In the last three decades, the presence of phospholipids in the nucleus has been shown and thoroughly investigated. A considerable amount of interest has been raised about nuclear inositol lipids, mainly because of their role in signaling acting. Here, we review the main issues of nuclear phospholipid localization and the role of nuclear inositol lipids and their related enzymes in cellular signaling, both in physiological and pathological conditions.

Expression of p120 - catenin in oral squamous cell carcinoma and apparently normal mucosa adjacent to oral squamous cell carcinoma

Background

An essential molecular occurrence in carcinogenesis that can lead to invasion and migration, predisposing cells to malignant transformation, involves alterations in cell adhesion molecules, such as p120 catenin. The destabilization of E-cadherin, caused by the loss or phosphorylation of p120 catenin (p120), regulates cadherin stability and turnover, impacting cell adhesiveness and migratory capacity. Consequently, p120 is associated with the invasiveness and progression of various human epithelial tumor types, including Oral Squamous Cell Carcinomas (OSCC). The present study aimed to assess and establish a correlation between the expression of p120 antibody in OSCC and Apparently Normal Mucosa Adjacent to OSCC (ANMAOSCC).

Material and Methods

The immunoexpression of p120 in 300 selected cases was categorized into two groups: OSCC (n = 150) and ANMAOSCC (n = 150). Two 4µm-thick tissue sections from the selected blocks were prepared. One section was stained with Hematoxylin and Eosin, while the other underwent immunohistochemical (IHC) staining using anti-p120 catenin antibody (clone No. EP66; Catalog No. PR062; PathnSitu, Wayne, PA, USA). The analysis of p120 immunoexpression included parameters such as intensity, percentage, and the location of staining.

Results

In OSCC, over 80% of cases expressed p120, with only 16% exhibiting loss of expression. In ANMAOSCC, all cells maintained p120 expression. In OSCC, p120 was predominantly localized to the membrane and cytoplasm in 76%, while in ANMAOSCC, over 90% showed membrane localization. Regarding positivity, only 19% of OSCC cases reported positivity in >50% of cells, compared to 64.7% in ANMAOSCC. The extent of staining in ANMAOSCC was observed up to the granular layer (45%) and corneal layer (19%).

Conclusions

The atypical staining pattern of p120 may indicate a loss of adhesion and could serve as a marker for identifying the malignant potential of ANMAOSCC and the aggressiveness of OSCC. Key words:Oral Squamous Cell Carcinoma, P120 Catenin, Cell Adhesion Molecules, Gene Expression Regulation.

Diet and Esophageal Cancer Risk: An Umbrella Review of Systematic Reviews and Meta-Analyses of Observational Studies

Diet may play an important role in the occurrence of esophageal cancer (EC). The aim of this umbrella review was to grade the evidence for the association between dietary factors and EC risk. A protocol for this review was registered with the PROSPERO database (CRD42021283232). Publications were identified by searching PubMed, EMBASE, Web of Science, Cochrane Database of Systematic Reviews, and CINAHL databases. Only systematic reviews and meta-analyses of observational studies (cohort studies, case-cohort studies, nested case-control studies) were eligible. AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews) was used to assess the methodological quality of included systematic reviews. For each association, random-effects pooled effect size, 95% CI, number of cases, 95% prediction interval, heterogeneity, small-study effect, and excess significance bias were calculated to grade the evidence. From 882 publications, 107 full-text articles were evaluated for eligibility, and 20 systematic reviews and meta-analyses describing 32 associations between dietary factors and EC risk were included in the present umbrella review. By assessing the strength and validity of the evidence, 1 association (positively associated with alcohol intake) was supported by highly suggestive evidence and 1 (inversely associated with calcium intake) showed a suggestive level of evidence. Evidence for 7 associations was weak (positively associated with red meat and processed-meat intake; inversely associated with whole grains, fruits, green leafy vegetables, green tea, and zinc intake). The remaining 23 associations were nonsignificant. In conclusion, the findings of this umbrella review emphasize that habitually consuming calcium, whole grains, fruits, green leafy vegetables, green tea, and zinc and reducing alcohol, red meat, and processed-meat intake are associated with a lower risk of EC. Since this umbrella review included only observational study data and some of the associations were graded as weak, caution should be exercised in interpreting these relations.

Vitamin D receptor regulates proliferation and differentiation of thyroid carcinoma via the E-cadherin-β-catenin complex

Thyroid cancer has the fastest rising incidence among cancers, especially for differentiated thyroid carcinoma (DTC). Although the prognosis of DTC is relatively good, if it changes to anaplastic thyroid carcinoma (ATC), the prognosis will be very poor. The prognosis of DTC is largely depending on the degree of cell differentiation and proliferation. However, whether the vitamin D receptor (VDR) plays a role in regulating the proliferation and the differentiation of DTC cells is unclear. In the present study, we found that VDR was upregulated in DTC tissues compared to the adjacent non-cancerous tissue. Knockdown of VDR increased proliferation and decreased differentiation proliferation in DTC cells in vitro as well as DTC cell-derived xenografts in vivo. In contrast, overexpression of VDR had an opposite effect. Knockdown of E-cadherin abolished VDR-induced suppression of proliferation and enhancement of differentiation of the DTC cells. Knockdown of β-catenin partially reversed the effect of the VDR knockdown. VDR increases the levels of E-cadherin in the plasma membrane and decreases the levels of β-catenin in the nucleus. VDR binds to E-cadherin and β-catenin in the plasma membrane of the DTC cell. Taken together, VDR inhibits DTC cell proliferation and promotes differentiation via regulation of the E-cadherin/β-catenin complex, potentially representing novel clues for a therapeutic strategy to attenuate thyroid cancer progression.

Overexpression of PTPRZ1 Regulates p120/ β -Catenin Phosphorylation to Promote Carcinogenesis of Oral Submucous Fibrosis

Background

Oral submucous fibrosis (OSF) is a potentially malignant disease of the oral cavity. New molecular predictors are needed to identify the high risk of malignant transformation in potentially malignant oral lesions. Our purpose is to explore PTPRZ1 and p120/β-catenin pathogenesis in the carcinogenesis of OSF to identify novel drug targets.

Methods

The expression of PTPRZ1, p120, and β-catenin in clinical tissues was detected. Then, PTPRZ1, p120, β-catenin, RhoA, Rac1, CDC42, cyclin D1, and c-myc expressions were detected by qRT-PCR and western blot. CCK-8 was applied to measure hOMF cells viability. Wound healing and transwell assay were applied to measure cell migration and invasion. Western blot and IF detected the distribution of p-p120 and p-β-catenin. Tumor formation experiment explored PTPRZ1 effects on OSF.

Results

PTPRZ1, p120, and β-catenin were abnormally expressed in cancer tissues. PTPRZ1 regulated the phosphorylation of p120/β-catenin. Western blot and IF showed that in the oe-NC group, p-p120 and p-β-catenin were expressed in the cell membrane. p-p120 and p-β-catenin were expressed in the cytoplasm and nucleus of the oe-PTPRZ1 group. In vitro experimental results revealed overexpression of PTPRZ1 and β-catenin, and silencing of p120 promoted cell proliferation, migration, and invasion. The tumor volume and weight in the sh-PTPRZ1 group were significantly reduced. IHC revealed the positive rate of PTPRZ1 was also low.

Conclusions

Overexpression of PTPRZ1 regulated the phosphorylation of p120/β-catenin to promote OSF malignancy.

Recent advances in understanding the molecular role of phosphoinositide-specific phospholipase C gamma 1 as an emerging onco-driver and novel therapeutic target in human carcinogenesis

Phosphoinositide metabolism is crucial intracellular signaling system that regulates a plethora of biological functions including mitogenesis, cell proliferation and division. Phospholipase C gamma 1 (PLCγ1) which belongs to phosphoinositide-specific phospholipase C (PLC) family, is activated by many extracellular stimuli including hormones, neurotransmitters, growth factors and modulates several cellular and physiological functions necessary for tumorigenesis such as cell survival, migration, invasion and angiogenesis by generating inositol 1,4,5-triphosphate (IP3) and diacylglycerol (DAG) via hydrolysis of phosphatidylinositol 4,5-biphosphate (PIP2). Cancer remains as a leading cause of global mortality and aberrant expression and regulation of PLCγ1 is linked to a plethora of deadly human cancers including carcinomas of the breast, lung, pancreas, stomach, prostate and ovary. Although PLCγ1 cross-talks with many onco-drivers and signaling circuits including PI3K, AKT, HIF1-α and RAF/MEK/ERK cascade, its precise role in carcinogenesis is not completely understood. This review comprehensively discussed the status quo of this ubiquitously expressed phospholipase as a tumor driver and highlighted its significance as a novel therapeutic target in cancer. Furthermore, we have highlighted the significance of somatic driver mutations in PLCG1 gene and molecular roles of PLCγ1 in several major human cancers, a knowledgebase that can be utilized to develop novel, isoform-specific small molecule inhibitors of PLCγ1.

Neurotrophins as Key Regulators of Cell Metabolism: Implications for Cholesterol Homeostasis

Neurotrophins constitute a family of growth factors initially characterized as predominant mediators of nervous system development, neuronal survival, regeneration and plasticity. Their biological activity is promoted by the binding of two different types of receptors, leading to the generation of multiple and variegated signaling cascades in the target cells. Increasing evidence indicates that neurotrophins are also emerging as crucial regulators of metabolic processes in both neuronal and non-neuronal cells. In this context, it has been reported that neurotrophins affect redox balance, autophagy, glucose homeostasis and energy expenditure. Additionally, the trophic support provided by these secreted factors may involve the regulation of cholesterol metabolism. In this review, we examine the neurotrophins' signaling pathways and their effects on metabolism by critically discussing the most up-to-date information. In particular, we gather experimental evidence demonstrating the impact of these growth factors on cholesterol metabolism.