The Hedgehog/GLI signaling pathway activates transcription of Slug (Snail2) in melanoma cells

KIAA0753 enhances osteoblast differentiation suppressed by diabetes

Diabetes-related bone loss represents a significant complication that persistently jeopardizes the bone health of individuals with diabetes. Primary cilia proteins have been reported to play a vital role in regulating osteoblast differentiation in diabetes-related bone loss. However, the specific contribution of KIAA0753, a primary cilia protein, in bone loss induced by diabetes remains unclear. In this investigation, we elucidated the pivotal role of KIAA0753 as a promoter of osteoblast differentiation in diabetes. RNA sequencing demonstrated a marked downregulation of KIAA0753 expression in pro-bone MC3T3 cells exposed to a high glucose environment. Diabetes mouse models further validated the downregulation of KIAA0753 protein in the femur. Diabetes was observed to inhibit osteoblast differentiation in vitro, evidenced by downregulating the protein expression of OCN, OPN and ALP, decreasing primary cilia biosynthesis, and suppressing the Hedgehog signalling pathway. Knocking down KIAA0753 using shRNA methods was found to shorten primary cilia. Conversely, overexpression KIAA0753 rescued these changes. Additional insights indicated that KIAA0753 effectively restored osteoblast differentiation by directly interacting with SHH, OCN and Gli2, thereby activating the Hedgehog signalling pathway and mitigating the ubiquitination of Gli2 in diabetes. In summary, we report a negative regulatory relationship between KIAA0753 and diabetes-related bone loss. The clarification of KIAA0753's role offers valuable insights into the intricate mechanisms underlying diabetic bone complications.

Unveiling the Dynamic Interplay between Cancer Stem Cells and the Tumor Microenvironment in Melanoma: Implications for Novel Therapeutic Strategies

Cutaneous melanoma still represents a significant health burden worldwide, being responsible for the majority of skin cancer deaths. Key advances in therapeutic strategies have significantly improved patient outcomes; however, most patients experience drug resistance and tumor relapse. Cancer stem cells (CSCs) are a small subpopulation of cells in different tumors, including melanoma, endowed with distinctive capacities of self-renewal and differentiation into bulk tumor cells. Melanoma CSCs are characterized by the expression of specific biomarkers and intracellular pathways; moreover, they play a pivotal role in tumor onset, progression and drug resistance. In recent years, great efforts have been made to dissect the molecular mechanisms underlying the protumor activities of melanoma CSCs to provide the basis for novel CSC-targeted therapies. Herein, we highlight the intricate crosstalk between melanoma CSCs and bystander cells in the tumor microenvironment (TME), including immune cells, endothelial cells and cancer-associated fibroblasts (CAFs), and its role in melanoma progression. Specifically, we discuss the peculiar capacities of melanoma CSCs to escape the host immune surveillance, to recruit immunosuppressive cells and to educate immune cells toward an immunosuppressive and protumor phenotype. We also address currently investigated CSC-targeted strategies that could pave the way for new promising therapeutic approaches for melanoma care.

SNAI2 enhances HPV‑negative cervical cancer cell dormancy by modulating u‑PAR expression and the activity of the ERK/p38 signaling pathway in vitro

The prognosis of patients with human papillomavirus (HPV)‑negative cervical cancer is significantly worse than that of patients with HPV‑positive cervical cancer. Understanding the mechanisms of this is crucial for preventing disease evolution. In the present study, the GV367‑snail family transcriptional repressor 2 (SNAI2) lentiviral vector was constructed and transduced into C‑33A cells. Subsequently, the proliferation of tumor cells was detected using the Cell Counting Kit (CCK)‑8 method. Flow cytometry was used to analyze the cell cycle progression of tumor cells. The glucose consumption of tumor cells was detected using an oxidase assay, and the senescence of tumor cells was detected using beta‑galactosidase staining. The gene expression and the activity of p38 and ERK1/2 were detected using reverse transcription‑quantitative PCR and western blotting, respectively. The C‑33A‑SNAI2 cell line was successfully established. Compared with HeLa and C‑33A‑Wild cells, the proliferation and percentage of G0/G1‑phase cells in the C‑33A‑SNAI2 group were decreased, as detected by the CCK‑8 assay (100±0 vs. 239.1±58.3 vs. 39.7±20.1, P<0.01) and flow cytometry (34.0±7.1% vs. 46.2±10.6% vs. 61.3±5.3%, P<0.05). Compared with the HeLa group, the glucose consumption of the C‑33A‑Wild and C‑33A‑SNAI2 groups was significantly decreased (P<0.01). The results of beta‑galactosidase staining showed that the proportion of beta‑galactosidase‑positive cells in the C‑33A‑SNAI2 group was significantly decreased compared with the C‑33A‑Wild group (P<0.01). Upregulation of SNAI2 enhanced the increase in p21 expression, and the decrease in CDK1, urokinase plasminogen activator receptor (u‑PAR) and cyclin D1 expression in C‑33A cells compared with C‑33A‑Wild cells (P<0.05). In addition, the activities of p38, ERK1/2 and the phosphorylated (p)‑ERK1/2/p‑p38 ratio were decreased in the C‑33A‑SNAI2 group compared with the C‑33A‑Wild and HeLa groups (P<0.05). In conclusion, SNAI2 enhanced HPV‑negative cervical cancer C‑33A cell dormancy, which was characterized by G0/G1 arrest, by the downregulation of u‑PAR expression, and a decrease in the activity of the p‑ERK1/2 and p‑p38MAPK signaling pathways in vitro. Cancer recurrence and metastases are responsible for most cancer‑related deaths. Given that SNAI2 is required for enhancing HPV‑negative cervical cancer cell dormancy, regulating this process may promote cervical tumor cells to enter a continuous dormant state, which could be a potential approach for tumor therapy.

The anti-tumor activity of tangeretin in esophageal squamous cell carcinoma by inhibiting GLI2-mediated transcription of GPNMB

Tangeretin (Tan), a citrus flavonoid, possesses a strong anti-tumor efficacy in various human cancers. However, the precise role of Tan in the development of esophageal squamous cell carcinoma (ESCC) remains unclear. RNA sequencing (RNA-seq) analysis was performed to observe the Tan-related genes in Tan-treated TE-1 cells. The direct relationship between GLI family zinc finger 2 (GLI2) and the promoter of glycoprotein non-metastatic melanoma protein B (GPNMB) was predicted by bioinformatics analysis and validated by luciferase reporter and chromatin immunoprecipitation (ChIP) assays. Cell survival after Tan treatment was assessed by CCK8 assay. Gene expression levels were evaluated by a qRT-PCR, western blot, or immunofluorescence method. Cell migration and invasion were detected by wound-healing and transwell assays. The function of Tan in vivo was examined using xenograft studies. Our data indicated anti-migration and anti-invasion functions of Tan in ESCC cells in vitro. Tan also diminished tumor growth in vivo. Mechanistically, Tan diminished the expression and transcriptional activity of GLI2 in ESCC cells. Silencing of GLI2 resulted in decreased expression of GPNMB by inhibiting GPNMB transcription via the binding site at the GPNMB promoter at position +(1539-1550). Moreover, Tan down-regulated GPNMB expression in ESCC cells, and re-expression of GPNMB reversed anti-migration and anti-invasion functions of Tan in ESCC cells. Our findings uncover anti-migration and anti-invasion effects of Tan in ESCC cells by down-regulating GPNMB by suppressing GLI2-mediated GPNMB transcription, providing new evidence that Tan can function as a therapeutic agent against ESCC.

Assessing the genetic risk of nodular melanoma using a candidate gene approach

BACKGROUND

Nodular melanoma (NM) is a challenge to diagnose early due to its rapid growth and more atypical clinical presentation, making it the largest contributor to melanoma mortality.

OBJECTIVES

Our study aim was to perform a rare-variant allele (RVA) analysis of whole-exome sequencing of patients with NM and non-NM (minor allele frequency ≤ 1% non-Finnish European) for a set of 500 candidate genes potentially implicated in melanoma.

METHODS

This study recruited 131 participants with NM and 194 with non-NM from South-east Queensland and patients with NM from Victoria to perform a comparative analysis of possible genetic differences or similarities between the two melanoma cohorts.

RESULTS

Phenotypic analysis revealed that a majority of patients diagnosed with NM were older males with a higher frequency of fair skin and red hair than is seen in the general population. The distribution of common melanoma polygenic risk scores was similar in patients with NM and non-NM, with over 28% in the highest quantile of scores. There was also a similar frequency of carriage of familial/high-penetrant melanoma gene and loss-of-function variants. We identified 39 genes by filtering 500 candidate genes based on the greatest frequency in NM compared with non-NM cases. The genes with RVAs of greatest frequency in NM included PTCH1, ARID2 and GHR. Rare variants in the SMO gene, which interacts with PTCH1 as ligand and receptor, were also identified, providing evidence that the Hedgehog pathway may contribute to NM risk. There was a cumulative effect in carrying multiple rare variants in the NM-associated genes. A 14.8-fold increased ratio for NM compared with non-NM was seen when two RVAs of the 39 genes were carried by a patient.

CONCLUSIONS

This study highlights the importance of considering frequency of RVA to identify those at risk of NM in addition to known high penetrance genes.