Stem Cell Markers CXCR-4 and CD133 Predict Aggressive Phenotype and Their Double Positivity Indicates Poor Prognosis of Oral Squamous Cell Carcinoma

HIV-1 Tat-induced disruption of epithelial junctions and epithelial-mesenchymal transition of oral and genital epithelial cells lead to increased invasiveness of neoplastic cells and the spread of herpes simplex virus and cytomegalovirus

Human immunodeficiency virus (HIV-1) transactivator Tat is a unique multi-functional viral protein secreted by infected cells. Although its primary function is to promote HIV-1 transcription, secreted Tat interacts with neighboring cells and induces numerous disease-associated pathological changes. Despite the substantial reduction of viral load and disease burden, Tat expression and secretion persist in people living with HIV who are undergoing treatment with highly effective combination antiretroviral therapy (cART). Tat interacts with both oral and genital epithelial cells and impairs their mucosal barrier functions, which facilitates the entry of other pathogenic viruses. Tat-mediated interactions with both human papillomavirus (HPV) -infected and HPV-negative neoplastic epithelial cells lead to epithelial-mesenchymal transition and increased invasiveness of malignant cells. Likewise, Tat-induced disruption of oral epithelial cell junctions leads to herpes simplex virus-1 (HSV-1) infection and spread via exposure of its receptor, nectin-1. HIV-1 Tat facilitates infection and spread of human cytomegalovirus (HCMV) by activating mitogen-activated protein kinases (MAPK) and promoting NF-κB signaling, both critical for the replication and production of progeny virions. HIV extracellular Tat also plays a critical role in human herpesvirus 8 (HHV8) -caused Kaposi sarcoma (KS) pathogenesis by synergizing with HHV-8 lytic proteins and promoting the proliferation, angiogenesis, and migration of endothelial cells. Collectively, these findings emphasize the critical impact of HIV-1 Tat on HIV/AIDS pathogenesis during the cART era and highlight the need for further research on the molecular mechanisms underlying Tat-mediated interactions with oral and genital mucosal epithelial cells.

Meta-Analysis of Prognostic Significance of Cancer Stem Cell Markers in Oral Squamous Cell Carcinoma

OBJECTIVE

Researchers have shown significant interest in cancer stem cells in recent years. CD44, CD24, CD133, and ALDH serve as indicators of cancer stem cell-like cells in Oral Squamous Cell Carcinoma. However, the prognostic significance of these Cancer Stem Cell markers in Squamous Cell Carcinoma is still debated. This study employed meta-analysis to evaluate the prognostic significance of cancer stem cells about Oral Squamous Cell Carcinoma.

METHODS

CD44, CD133, CD24, and ALDH markers were analyzed in 19 retrospective studies to determine their relationship with prognosis and clinicopathological parameters. Risk ratios (RRs) and odds ratios (ORs) were calculated for 3-years survival rates and clinicopathological parameters, respectively, using a fixed-effects model.

RESULT

The finding of our study based on extracted survival rates showed that cancer stem cell markers, CD133 expression was related with the poor prognosis (RR= 1.62 ,95% CI = 1.08-2.44, P= 0.02). ALDH expression significantly correlated with lymph node metastasis (OR= 4.13, 95% Cl= 1.88-9.10, P<0.001) and clinical staging (OR= 2.26, 95% CI= 1.05-4.88, P= 0.04).

CONCLUSION

The findings indicate that CSC markers could be used to predict oral cancer prognosis. Our study contributes to the literature on survival outcomes of Oral Squamous Cell Carcinoma. These findings offer a structure for the advancement of cancer treatments that specifically target cancer stem cells. Conducting additional studies with a broader group of patients will help confirm the role of cancer stem cells as dependable predictors of prognosis.

Sodium butyrate enhances titanium nail osseointegration in ovariectomized rats by inhibiting the PKCα/NOX4/ROS/NF-κB pathways

BACKGROUND

Elevated levels of oxidative stress as a consequence of estrogen deficiency serve as a key driver of the onset of osteoporosis (OP). In addition to increasing the risk of bone fractures, OP can reduce the bone volume proximal to titanium nails implanted to treat these osteoporotic fractures, thereby contributing to titanium nail loosening. Sodium butyrate (NaB) is a short-chain fatty acid produced by members of the gut microbiota that exhibits robust antioxidant and anti-inflammatory properties.

METHODS

OP fracture model rats parameters including bone mineral density (BMD), new bone formation, and the number of bonelets around the implanted nail were analyzed via micro-CT scans, H&E staining, and Masson's staining. The protective effects of NaB on such osseointegration and the underlying mechanisms were further studied in vitro using MC3T3-E1 cells treated with carbonyl cyanide m-chlorophenylhydrazone (CCCP) to induce oxidative stress. Techniques including Western immunoblotting, electron microscopy, flow cytometry, alkaline phosphatase (ALP) staining, and osteoblast mineralization assays were employed to probe behaviors such as reactive oxygen species production, mineralization activity, ALP activity, protein expression, and the ability of cells to attach to and survive on titanium plates.

RESULTS

NaB treatment was found to enhance ALP activity, mineralization capacity, and Coll-I, BMP2, and OCN expression levels in CCCP-treated MC3T3-E1 cells, while also suppressing PKC and NF-κB expression and enhancing Nrf2 and HO-1 expression in these cells. NaB further suppressed intracellular ROS production and malondialdehyde levels within the cytosol while enhancing superoxide dismutase activity and lowering the apoptotic death rate. In line with these results, in vivo work revealed an increase in BMD in NaB-treated rats that was associated with enhanced bone formation surrounding titanium nails.

CONCLUSION

These findings indicate that NaB may represent a valuable compound that can be postoperatively administered to aid in treating OP fractures through the enhancement of titanium nail osseointegration.

Protein Kinase C (PKC) Isozymes as Diagnostic and Prognostic Biomarkers and Therapeutic Targets for Cancer

Protein kinase C (PKC) is a large family of calcium- and phospholipid-dependent serine/threonine kinases that consists of at least 11 isozymes. Based on their structural characteristics and mode of activation, the PKC family is classified into three subfamilies: conventional or classic (cPKCs; α, βI, βII, and γ), novel or non-classic (nPKCs; δ, ε, η, and θ), and atypical (aPKCs; ζ, ι, and λ) (PKCλ is the mouse homolog of PKCι) PKC isozymes. PKC isozymes play important roles in proliferation, differentiation, survival, migration, invasion, apoptosis, and anticancer drug resistance in cancer cells. Several studies have shown a positive relationship between PKC isozymes and poor disease-free survival, poor survival following anticancer drug treatment, and increased recurrence. Furthermore, a higher level of PKC activation has been reported in cancer tissues compared to that in normal tissues. These data suggest that PKC isozymes represent potential diagnostic and prognostic biomarkers and therapeutic targets for cancer. This review summarizes the current knowledge and discusses the potential of PKC isozymes as biomarkers in the diagnosis, prognosis, and treatment of cancers.

Pathogenesis and prognosis of primary oral squamous cell carcinoma based on microRNAs target genes: a systems biology approach

Oral squamous cell carcinoma (OSCC) is the most prevalent head and neck malignancy, with frequent cervical lymph-node metastasis, leading to a poor prognosis in OSCC patients. The present study aimed to identify potential markers, including microRNAs (miRNAs) and genes, significantly involved in the etiology of early-stage OSCC. Additionally, the main OSCC's dysregulated Gene Ontology annotations and significant signaling pathways were identified. The dataset GSE45238 underwent multivariate statistical analysis in order to distinguish primary OSCC tissues from healthy oral epithelium. Differentially expressed miRNAs (DEMs) with the criteria of p-value < 0.001 and |Log2 fold change| > 1.585 were identified in the two groups, and subsequently, validated targets of DEMs were identified. A protein interaction map was constructed, hub genes were identified, significant modules within the network were illustrated, and significant pathways and biological processes associated with the clusters were demonstrated. Using the GEPI2 database, the hub genes' predictive function was assessed. Compared to the healthy controls, main OSCC had a total of 23 DEMs. In patients with head and neck squamous cell carcinoma (HNSCC), upregulation of CALM1, CYCS, THBS1, MYC, GATA6, and SPRED3 was strongly associated with a poor prognosis. In HNSCC patients, overexpression of PIK3R3, GIGYF1, and BCL2L11 was substantially correlated with a good prognosis. Besides, “proteoglycans in cancer” was the most significant pathway enriched in the primary OSCC. The present study results revealed more possible mechanisms mediating primary OSCC and may be useful in the prognosis of the patients with early-stage OSCC.

Current Status of 68Ga-Pentixafor in Solid Tumours

Chemokine receptor CXCR4 is overexpressed in neoplasms and its expression is related to tumour invasion, metastasis and aggressiveness. ⁶⁸Ga-Pentixafor is used to non-invasively image the expression of CXCR4 in tumours and has been widely used in haematological malignancies. Recent evidence shows that therapies targeting CXCR4 can increase the chemosensitivity of the tumour as well as inhibit tumour metastasis and aggressiveness. ⁶⁸Ga-Pentixafor has shown promise as an elegant radiotracer to aid in the selection of patients whose tumours demonstrate CXCR4 overexpression and who therefore may benefit from novel therapies targeting CXCR4. In addition, its therapeutic partners ¹⁷⁷Lu- and ⁹⁰Y-Pentixather have been investigated in the treatment of patients with advanced haematological malignancies, and initial studies have shown a good treatment response in metabolically active lesions. ⁶⁸Ga-Pentixafor in solid tumours complements ¹⁸F-FDG by providing prognostic information and selecting patients who may benefit from therapies targeting CXCR4. This review summarises the available literature on the potential applications of ⁶⁸Ga-Pentixafor in solid tumours.

TRIM28 Is a Novel Regulator of CD133 Expression Associated with Cancer Stem Cell Phenotype

CD133 is an extensively studied marker of the most malignant tumor cell population, designated as cancer stem cells (CSCs). However, the function of this glycoprotein and its involvement in cell regulatory cascades are still poorly understood. Here we show a positive correlation between the level of CD133 plasma membrane expression and the proliferative activity of cells of the Caco-2, HT-29, and HUH7 cancer cell lines. Despite a substantial difference in the proliferative activities of cell populations with different levels of CD133 expression, transcriptomic and proteomic profiling revealed only minor distinctions between them. Nonetheless, a further in silico assessment of the differentially expressed transcripts and proteins revealed 16 proteins that could be involved in the regulation of CD133 expression; these were assigned ranks reflecting the apparent extent of their involvement. Among them, the TRIM28 transcription factor had the highest rank. The prominent role of TRIM28 in CD133 expression modulation was confirmed experimentally in the Caco2 cell line clones: the knockout, though not the knockdown, of the TRIM28 gene downregulated CD133. These results for the first time highlight an important role of the TRIM28 transcription factor in the regulation of CD133-associated cancer cell heterogeneity.

Emodin exerts antitumor effects in ovarian cancer cell lines by preventing the development of cancer stem cells via epithelial mesenchymal transition

Ovarian cancer has the worst prognosis among all types of gynecological malignancies and patients are often diagnosed at an advanced stage with distant metastasis. In the present study, it was found that emodin, a small molecular chemical drug derived from natural plants, has antitumor effects on ovarian cancer cells. Emodin induced cytotoxicity and inhibited proliferation in the ovarian cancer cell lines, SK-OV-3, A2780 and PA-1. In addition, emodin inhibited the migration and invasion abilities of the ovarian cancer cells by inhibiting epithelial-mesenchymal transition (EMT), which was evidenced by the downregulation of N-cadherin and vimentin, and the upregulation of E-cadherin protein expression levels. When a subcutaneous xenograft SK-OV-3 tumor mouse model was used, emodin notably reduced the tumor growth rate and inhibited tumor cell proliferation. Furthermore, mechanical analysis revealed that emodin markedly inhibited EMT and reduced the stemness of tumor cells, which was evidenced by the decrease in the protein expression of CD133 and Oct4. Pulmonary metastasis of the ovarian cancer cells was significantly suppressed in the tumor mouse model by the administration of emodin. In addition, flow cytometry analysis indicated that emodin significantly reduced the proportion of ovarian cancer stem-like cells in metastatic lung tissues. In conclusion, emodin, a potent inhibitor of EMT, could serve as a potential candidate for ovarian cancer therapy.