The effects of proliferating cell nuclear antigen and p53 in patients with oral squamous cell carcinoma: a systematic review and meta-analysis

RBMS1 interference inhibits malignant progression of glioblastoma cells and promotes ferroptosis

BACKGROUND

Glioblastoma (GBM) is a brain tumor characterized by the highest malignancy and the poorest prognoses. RNA binding motif single strand interacting protein 1 (RBMS1) has been implicated to be involved in various cancer progression. This study was conceived to explore the role and the mechanism of RBMS1 in GBM.

MATERIALS

RT-qPCR and western blot were used to evaluate RBMS1 expression and examine the transfection efficiency of sh-RBMS1. Cell proliferation was detected using CCK-8 assay and colony formation assay while cell apoptosis was detected with flow cytometry. Cell migration and invasion were detected with wound healing and transwell assay. The activities of MMP2 and MMP9 were detected using gelatin zymography. Western blot was used to measure proliferation-, apoptosis-, ferroptosis- and EMT-related proteins. Lipid peroxidation was detected with TBARS Assay Kit and lipid ROS was detected with a BODIPY 581/591 C11 kit. The total iron level was detected using corresponding assay kits.

RESULTS

According to GEPIA database, RBMS1 expression was upregulated in GBM and the present study found that RBMS1 expression was upregulated in GBM cells. After interfering RBMS1, GBM cell proliferation, migration, invasion and EMT process were inhibited while cell apoptosis and ferroptosis were promoted. However, ferroptosis inhibitor Fer-1 partially counteracted the protective effects of RBMS1 knockdown on GBM.

CONCLUSION

Collectively, this study revealed that RBMS1 silence inhibited the malignant progression of GBM possibly through ferroptosis.

Astilbin Induces Apoptosis in Oral Squamous Cell Carcinoma through p53 Reactivation and Mdm-2 Inhibition

Oral squamous cell carcinoma (OSCC) is a frequently occurring malignancy in the head and neck region. The most commonly mutated gene in OSCC is the tumor suppressor gene p53 (TP53), linked to lower survival and treatment resistance in OSCC patients. Astilbin is a flavonoid amongst several herbal treatments with a variety of pharmacological actions mainly including antioxidant, anti-inflammatory, and anti-cancer characteristics. This study evaluated the effects of astilbin on proliferation of OSCC cell lines SCC90 and SCC4 (bearing a p53 mutation) in relevance to p53 and Mdm-2 pathways. Astilbin inhibited the proliferation of SCC4 and SCC90 cells in a dose- and time-dependent manner. The IC50 values for both the cell lines were about 75 μM for astilbin. A p53 activator (RITA) was used to determine the effects of astilbin on p53 activity, and the results demonstrated synergistic reduction in cell growth. However, when combined with pifithrin-α (a p53 inhibitor), astilbin demonstrated a strong inhibition of its response. Astilbin reduced the mitochondrial membrane potential in SCC4 cells, which is a sign of apoptotic activity. Astilbin decreased the amounts of Mdm-2 (negative regulator of p53) and increased the expression of the p53 gene and protein. In a p53-dependent manner, astilbin suppressed the ability of SCC4 cells to form colonies and heal wounds. This was followed by the induction of mitochondrial intrinsic apoptosis via the activation of caspases 9 and 3, cleavage of PARP, and the suppression of pro-apoptotic Bid. Astilbin-induced p53-mediated apoptosis in OSCC cells as herbal medicinal ingredients.

Pathological examination of factors involved in PD-L1 expression in patients with oral tongue squamous cell carcinoma

BACKGROUND

Tumor tissues comprise cancer cells and stromal cells, and their interactions form the cancer microenvironment. Therefore, treatments targeting cells other than cancer cells are also actively being developed, and among them, treatment targeting PD-1, an immune checkpoint molecule that is important in tumor immune evasion, has also been indicated for head and neck cancer. PD-L1, a ligand of PD-1, is expressed in both tumor cells and stromal cells, and the scoring system based on the combined positivity rates of both types of cells, the combined positive score (CPS), is used for predicting treatment effect. However, much is unknown regarding the expression of PD-L1. In this study, we histopathologically examined factors controlling the expression of PD-1/PD-L1. This study included 37 patients who underwent resection surgery for tongue squamous cell carcinoma in the Department of Oral and Maxillofacial Surgery at Tokyo Dental College Suidobashi Hospital. The expression levels of PD-L1, α-SMA, and p53 were assessed by immunohistochemical staining.

RESULTS

Seven participants had CPS ≥ 20, twenty-four participants had 1 ≤ CPS < 20, and six participants had CPS < 1. The overall positivity rate of α-SMA, a marker for cancer-associated fibroblasts (CAFs), was 27% (10/37 participants), and the positivity rates of α-SMA for the three CPS groups were 85.7% (6/7 participants), 16.7% (4/24 participants), and 0% (0/6 participants), respectively. In addition, the overall positivity rate of p53 was 37.8% (14/37 participants), and the positivity rates of p53 for the three CPS groups were 71.4% (5/7 participants), 37.5% (9/24 participants), and 0% (0/6 participants), respectively.

CONCLUSIONS

The expression of PD-L1 demonstrated an association with α-SMA and p53 positivity. In addition, compared with the expression of p53, the expression of α-SMA demonstrated a higher association with PD-L1 expression in patients with a high CPS. The abovementioned findings suggest that the interactions between CAFs, cancer cells, and immunocompetent cells may regulate the expression of PD-L1.

Solanine Inhibits Proliferation and Angiogenesis and Induces Apoptosis through Modulation of EGFR Signaling in KB-ChR-8-5 Multidrug-Resistant Oral Cancer Cells

Background: The most important factors contributing to multi-drug resistance in oral cancer include overexpression of the EGFR protein and the downstream malignancy regulators that are associated with it. This study investigates the impact of solanine on inflammation, proliferation, and angiogenesis inhibition in multidrug-resistant oral cancer KB-Chr-8-5 cells through inhibition of the EGFR/PI3K/Akt/NF-κB signaling pathway. Methods: Cell viability was assessed using an MTT assay to evaluate cytotoxic effects. Production of reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨM), and AO/EtBr staining were analyzed to assess apoptosis and mitochondrial dysfunction. Western blotting was employed to examine protein expression related to angiogenesis, apoptosis, and signaling pathways. Experiments were conducted in triplicate. Results: Solanine treatment at concentrations of 10, 20, and 30 μM significantly increased ROS production, which is indicative of its antioxidant properties. This increase was associated with decreased mitochondrial membrane potential (ΔΨM) with p < 0.05, suggesting mitochondrial dysfunction. Inhibition of EGFR led to reduced activity of PI3K, Akt, and NF-κB, resulting in decreased expression of iNOS, IL-6, Cyclin D1, PCNA, VEGF, Mcl-1, and HIF-1α and increased levels of the apoptotic proteins Bax, caspase-9, and caspase-3. These changes collectively inhibited the growth of multidrug-resistant (MDR) cancer cells. Conclusions: Solanine acts as a potent disruptor of cellular processes by inhibiting the EGFR-mediated PI3K/Akt/NF-κB signaling pathway. These results suggest that solanine holds promise as a potential preventive or therapeutic agent against multidrug-resistant cancers.

Systematic evaluation of TP53 codon 72 polymorphism associated with onset and progression of oral potentially malignant disorders

BACKGROUND

Recently, a systematic review and meta-analysis demonstrated that overexpression of p53 immunoprotein was significantly associated with progression risk of oral potentially malignant disorders (OPMD). However, the results of investigations on TP53 genetic typing in OPMD were inconsistent and inconclusive.

METHODS

A systematic evaluation was conducted to identify all eligible case-control studies on the association of TP53 codon 72 polymorphism with both onset and progression of OPMD.

RESULTS

A total of 768 OPMD patients and 1173 healthy individuals were identified from 12 eligible case-control studies on TP53 codon 72 polymorphism OPMD onset. In overall and subgroup analyses, no significantly risk of OPMD onset was observed in the cases for genetic models including allele C vs. G, homozygote CC vs. GG, heterozygote GC vs. GG, dominant GC + CC vs. GG, and recessive CC vs. GG + GC (all P-value of association test > 0.05). Further, a total of 465 OPMD patients and 775 oral squamous cell carcinoma (OSCC) ones were identified from 8 eligible case-control studies on this polymorphism in OPMD progression to OSCC. The analyses revealed that there was also no significantly risk of OPMD progression in the cases for the genetic models (all P-value of association test > 0.05).

CONCLUSION

Our data of a pooled-analysis indicates that TP53 codon 72 polymorphism may not act as genetic factor for the risk of OPMD onset and progression. Combined with the conclusion by a systematic review and meta-analysis, we put forward a new opinion that TP53 genetic typing cloud not influence p53 protein expression in OPMD.

Comparative Analysis of Cluster of Differentiation 57 and Proliferating Cell Nuclear Antigen Expression in Different Grades of Oral Squamous Cell Carcinoma: An Immunohistochemical Study

BACKGROUND

 The immune defense against tumor cells is mainly mediated by the natural killer (NK) cells. Cluster of differentiation 57 (CD57) is a 110-kd glycoprotein, typically expressed by the NK cells, attacks the cancer cells and inhibits tumor development. Proliferating cell nuclear antigen (PCNA) is a 36-kd auxiliary protein for DNA polymerase delta that correlates with cell proliferation and DNA synthesis. It is an essential component of DNA replication, DNA recombination, and DNA repair. The uncoordinated proliferation of PCNA protein characterizes the biological behavior of malignant lesions.

AIM

 The aim of the present study is to compare and correlate the expression of CD57 and PCNA in different grades of oral squamous cell carcinoma (OSCC) by immunohistochemistry.

MATERIALS AND METHODS

 This retrospective analysis comprises 30 samples of various grades of OSCCs and 10 samples of healthy mucosa. Sections of 4-5 µm thickness were done and stained with monoclonal anti-PCNA and anti-CD57 antibodies. The statistical package for social science (SPSS) version 16.0 software (IBM Corp., Armonk, NY) was used to analyze the data in this study. The expression of CD57 and PCNA was compared and correlated between the groups using analysis of variance (ANOVA) post hoc, Dunnet t-test, and Pearson's correlation coefficient test. For statistical significance, a p-value of 0.05 or less was used.

RESULTS

A significant decrease in CD57 labeling index was seen from well-differentiated squamous cell carcinoma (16.63 ± 2.33) to poorly differentiated squamous cell carcinoma (5.53 ± 1.20) whereas the significant increase in PCNA labeling index was noted from well-differentiated squamous cell carcinoma (45.88 ± 2.20), followed by moderately differentiated and poorly differentiated squamous cell carcinoma (72.77 ± 4.35).

CONCLUSION

 The combination of CD57 and PCNA biomarkers appears to be good indicators of the immune status of the patient and the aggressiveness of the lesion.

Immunoexpression of p53 mutant-type in Iranian patients with primary and recurrence oral squamous cell carcinoma

Mutations in tumor suppressor p53 protein can occur at different phases of malignant transformation and affect the patient's prognosis. This study aimed to evaluate the expression of mutant p53 protein in Iranian patients with the primary and recurrence oral squamous cell carcinoma (OSCC). This retrospective cross-sectional study conducted on a group of patients with the primary OSCC (n=122) and the control subjects with oral noncancerous reactive lesions (n=80). Immunohistochemistry was performed with the DO-7 monoclonal antibody against p53 protein, and samples with ≥10% immunostaining were considered positive. Statistical analyses were carried out using SPSS. Positive staining for p53 was observed in none of the control subjects and 57.4% (70 of 122) of the primary OSCC patients (p<0.0001, OR=107.69, 95%CI=6.49-179.0). The p53 immunopositivity had no significant differences between males and females (54.2% vs. 62%, p=0.390), but significantly different between those aged below and over 50 years (p<0.0001, OR=4.52, 95%CI=1.07-12.05). During follow-up, OSCC recurrence occurred in 104 patients, but the phenotype of the mutant p53 protein in patients who relapsed was the same as in matched primary tumors (p=0.763). Risk of recurrence had no significant differences between p53-positive and p53-negative cases (p=0.953), males and females (p=0.263), and age below and over 50 years (p=0.223). Despite its confirmed diagnostic value, the immunoexpression of the p53 mutant protein in OSCC in cancer recurrence was the same as in the primary tumor. However, further studies with a larger sample size and longer follow-up are needed to confirm or change our conclusions.