Correlation of CD133 and Oct-4 expression with clinicopathological and demographic parameters in oral squamous cell carcinoma patients

Intricate relationship between cancer stemness, metastasis, and drug resistance

Cancer stem cells (CSCs) are widely acknowledged as the drivers of tumor initiation, epithelial-mesenchymal transition (EMT) progression, and metastasis. Originating from both hematologic and solid malignancies, CSCs exhibit quiescence, pluripotency, and self-renewal akin to normal stem cells, thus orchestrating tumor heterogeneity and growth. Through a dynamic interplay with the tumor microenvironment (TME) and intricate signaling cascades, CSCs undergo transitions from differentiated cancer cells, culminating in therapy resistance and disease recurrence. This review undertakes an in-depth analysis of the multifaceted mechanisms underlying cancer stemness and CSC-mediated resistance to therapy. Intrinsic factors encompassing the TME, hypoxic conditions, and oxidative stress, alongside extrinsic processes such as drug efflux mechanisms, collectively contribute to therapeutic resistance. An exploration into key signaling pathways, including JAK/STAT, WNT, NOTCH, and HEDGEHOG, sheds light on their pivotal roles in sustaining CSCs phenotypes. Insights gleaned from preclinical and clinical studies hold promise in refining drug discovery efforts and optimizing therapeutic interventions, especially chimeric antigen receptor (CAR)-T cell therapy, cytokine-induced killer (CIK) cell therapy, natural killer (NK) cell-mediated CSC-targeting and others. Ultimately use of cell sorting and single cell sequencing approaches for elucidating the fundamental characteristics and resistance mechanisms inherent in CSCs will enhance our comprehension of CSC and intratumor heterogeneity, which ultimately would inform about tailored and personalized interventions.

OCT4's role and mechanism underlying oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), a common malignancy of the head and neck, ranks sixth worldwide in terms of cancers with the most negative impact, owing to tumor relapse rates, cervical lymphnode metastasis, and the lack of an efficacious systemic therapy. Its prognosis is poor, and its mortality rate is high. Octamer-binding transcription factor 4 (OCT4) is a member of the Pit-Oct-Unc (POU) family and is a key reprogramming factor that produces a marked effect in preserving the pluripotency and self-renewal state of embryonic stem cells (ESCs). According to recent studies, OCT4 participates in retaining the survival of OSCC cancer stem cells (CSCs), which has far-reaching implications for the occurrence, recurrence, metastasis, and prognosis of oral carcinogenesis. Therefore, we summarize the structure, subtypes, and function of OCT4 as well as its role in the occurrence, progression, and prognosis of OSCC.

High CD44 Immunoexpression Correlates with Poor Overall Survival: Assessing the Role of Cancer Stem Cell Markers in Oral Squamous Cell Carcinoma Patients from the High-Risk Population of Pakistan

Oral squamous cell carcinoma (OSCC) is a top-ranked cancer in the Pakistani population, and patient survival has remained unchanged at ∼50% for several decades. Recent advances have claimed that a subset of tumour cells, called cancer stem cells (CSCs), are responsible for tumour progression, treatment resistance, and metastasis, which leads to a poor prognosis. This study investigated the impact of CSC markers expression on overall survival (OS) and disease-free survival (DFS) of OSCC patients. Materials and Methods. Immunohistochemistry was used to evaluate CD44, CD133, L1CAM, and SOX2 expression in a well-characterized cohort of 100 Pakistani patients with primary treatment naïve OSCC. The immunoreactivity for each marker was correlated with patient clinicopathologic characteristics, oral cancer risk chewing habits, and survival. The minimum follow-up time for all patients was five years, and survival estimates were calculated using the Kaplan–Meier method and Cox proportional hazards model. Results. In this cohort of 100 patients, there were 57 males and 43 females. The median OS and DFS time durations observed were 64 and 52.5 months, respectively. Positive expression for CD44, CD133, L1CAM, and SOX2 was observed in 33%, 23%, 41%, and 63% of patients. High CD44 expression correlated with decreased OS (P=0.047) but did not influence DFS. However, CD133, L1CAM, and SOX2 had no effect on either OS or DFS. Tonsils, nodal involvement, and AJCC stage were independent predictors of worse OS and DFS both. Conclusion. Of the CSC markers investigated here, only CD44 was a predictor for poor OS. CD44 was also associated with advanced AJCC and T stages. Interestingly, CD133 was significantly lower in patients who habitually consumed oral cancer risk factors.

Cancer Stem Cell Traits in Tumor Spheres Derived from Primary Laryngeal Carcinoma Cell Lines

Objective

Cancer stem cells (CSCs) belong to a subpopulation of undifferentiated cells present within tumors that have the potential to regenerate, differentiate, maintenance of pluripotency, drug resistance, and tumorigenicity when transplanted into an innate host. These can influence the growth and behavior of these tumors and are used to investigate the initiation, progression, and treatment strategies of laryngeal cancer. Research on CSC science and targeted therapies were hinge on their isolation and/or enrichment procedures. The object of the study is to isolate cancer stem cells from primary laryngeal carcinoma (CSCPLC) by tumor spheres enrichment. We checked the properties of self-renewal, stemness, clonogenicity, and chemotherapeutic resistance.

Materials and Methods

We performed tumor sphere formation assay (primary, secondary, and tertiary) chemotherapy resistance by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay were performed to evaluate the CSC cells. Immunofluorescence for stem cell markers (CD133+, CD44+) and gene expression of stem cell markers for CD133+, CD44+, OCT4, SOX2, and NANOG was done using the real-time polymerase chain reaction technique.

Results

We were able to isolated CSC subpopulations from PLC cell lines by the tumor sphere method. These cells exhibited good primary, secondary, and tertiary tumor sphere formation efficiency and also disclosed a resistant index of more than 2. Immunofluorescence for stem cell markers (CD133+ and CD44+) confirms the presence of CSC. There was significantly higher mRNA expression of stem cell markers in CSC enriched subpopulations compared to the parental cell lines.

Conclusion

We conclude that tumor spheres enrichment is an efficient, economical, and reliable approach for the isolation and characterization of CSC from PLC cell lines. These cells demonstrated the properties of self-renewal, stemness, clonogenicity, and chemotherapeutic resistance.

Association between SOX2 and OCT4 expression and the chemoradiation therapeutic response in undifferentiated non-keratinizing nasopharyngeal carcinoma

BACKGROUND Self-renewal ability of cancer stem cells (CSS) is one of the possible causes for nasopharyngeal carcinoma (NPC) to relapse and metastasize. SOX2 and OCT4 are markers for expression of the embryonic stem cells and crucial for the progression of various malignancies. This study was aimed to analyze the association between SOX2 and OCT4 expression and chemoradiation therapeutic response in undifferentiated non-keratinizing NPC. METHODS This cross-sectional study used archival data from Department of Anatomical Pathology, Faculty of Medicine, Universitas Indonesia, Cipto Mangunkusumo Hospital from January 2014 to December 2016. The outcomes were classified into good-response (complete and partial response) and poor-response groups (progressive and stable disease) based on response evaluation criteria in solid tumors (RECIST). SOX2 and OCT4 immunohistochemistry staining was performed using the initial specimen (before chemoradiation therapy) and positively expressing tumor cells were counted. Staining intensity was graded as: strong, moderate, weak, and negative. Strong and moderate staining was considered positive expression. RESULTS 33 males and 8 females were included; 48% were ≥50 years old. Most of the patients had stage IV (n = 35) and several patients had stage II (n = 3) and III (n = 3). More cells expressed OCT4 in the good-response group than the poor-response group (61.3% versus 37.0%, p = 0.009). Meanwhile, there were less cells expressing SOX2 in the good-response group than the poor-response group (36.3% versus 61.1%, p = 0.097). CONCLUSIONS This study suggests that OCT4 is a potential predictive marker for therapeutic response in patients with NPC.

CD133 Role in Oral Carcinogenesis

Objective:

to investigate CD133 immunoexpression, cancer stem cells marker, in oral epithelial dysplasias (OEDs) and oral squamous cells carcinomas (OSCCs) and understandits possible involvement in the malignant transformation process of these lesions and to better elucidate their biological behavior.

Material and methods:

Tissue samples of 15 cases of OSCCs and 15 OEDs were subjected to CD133 antibody immunohistochemistry reactions. The analysis used quantitative parameters (number of immunostained cells regardless of immunostaining sublocations).

Results:

All samples of OSCCs and OEDs showed positive immunostaining, with no significant difference between these groups (p = 0.283). We did not observe statistical difference between the degree of dysplasia and the amount of CD133+ cells (p = 0.899). CD133 immunoexpression showed no association with the OEDs and OSCCs sites. It was observed that nuclear and cytoplasmic immunostaining was more evident with the progression of the malignant process.

Conclusion:

It is suggested that the CD133 cellular localization together with the histopathological criteria of OEDs classification can contribute to provide more concrete indications about the oral carcinogenesis process.

Indirect Immunofluorescence and Tumorspheres Enrichment Technique for Identifying Cancer Stem Cell Markers in Cancer Cell Lines From Primary Oral Cancer Tissues: An In Vitro Study

Aim:

The cancer stem cells (CSCs) are known to be responsible for drug resistance and cancer relapse in the treatment of cancer. Identification and isolation of CSCs and study of their properties will play a crucial role in developing an effective drug against these targets. The aim of the study was to isolate CSCs from primary cancer by the tumorspheres enrichment method, to confirm by indirect immunofluorescence and gene expression of stem cell markers by using real-time polymerase chain reaction (RT-PCR) technique.

Materials and Methods:

In this in vitro study, we enriched oral CSCs through tumorsphere formation assay from seven primary cultures of OSCC patients with defined serum media. The expression and localization of the cell surface markers of CD133 and CD44 were tested by indirect immunofluorescence. Gene expression of stem cell markers such as CD44, CD133, Oct4, Sox2, and Nanog were quantified by RT-PCR technique. One-way analysis of variance was applied to analyze gene expression.

Results:

Tumorsphere formation has been used to isolate the CSCs from the OSCC tissue culture. Both CD133 and CD44 antibody confirmed the presence of CSCs through indirect immunofluorescence. In comparison to parental cell lines, the expression levels of CD133, CD44, Oct4, Sox2, and Nanog stem cell were significantly higher in CSC-enriched subpopulations.

Conclusions:

The cost-effective spheroid enrichment and the indirect immunofluorescence methods are useful for the isolation of CSCs from the primary tumor.

Characterisation of a subpopulation of CD133+ cancer stem cells from Chinese patients with oral squamous cell carcinoma

Cancer stem cells (CSCs) play a critical role in cancer development and growth. The aim of this study was to identify and isolate CSCs from populations of primary oral squamous cell carcinoma (OSCC) cells, which were obtained from OSCC specimens and identified by cell morphology and immunohistochemical staining for keratin. CD133⁺ cells detected by flow cytometry comprised 0.41 ± 0.06% of primary OSCC cells and were isolated from primary OSCC cell populations using magnetic-activated cell sorting, revealing that 93.39% of high-purity CD133⁺ cells were in the G0/G1 phase of the cell cycle. Additionally, the growth rate of CD133⁺ cells was higher than that of CD133⁻ cells, and in vivo tumourigenesis experiments showed that the tumourigenic ability of CD133⁺ cells was markedly stronger than that of CD133⁻ cells. Moreover, CD133⁺ cells showed increased chemotherapeutic resistance to cisplatin and higher self-renewal ability according to sphere-formation assay, as well as higher mRNA levels of stemness-associated genes, including NANOG, SOX2, ALDH1A1, and OCT4. These results indicated that OSCC cells, which share certain characteristics of CSCs, harbour CD133⁺ cells potentially responsible for OSCC aggressiveness, suggesting CD133 as a potential prognostic marker and therapeutic target.

The current markers of cancer stem cell in oral cancers

Head and neck cancer (HNC) constitute 5% of all reported cancers. Among all, the oral cavity cancer is the most frequent type of HNC which accounts for over half of HNC cases. Mouth cancer ranks the sixth leading cause of cancer-related mortality. Generally, conventional chemotherapy has shown success at decreasing relapse and metastasis rates and improves the overall prognosis. Recently, target therapy and targeted drug delivery systems have been introduced as promising treatments. The elimination of efficiency of current therapeutic strategies due to the spared cancer stem cells that cause chemotherapy resistance, relapse and metastasis. Inefficiency methodologies in the elimination of all cancer cells in the body are a major problem that remained to be resolved before to confront the new cancer therapies. Many studies imply to cancer stem cell markers as important agents for targeted anti-cancer as well as improving chemotherapy efficiencies. The potentials of targeted cancer therapy led us to search for novel markers in the mouth cancer stem cells especially in rare cancers. The aimed of this research was, first a comprehensive critical review of the previous studies on the markers of cancer stem cells in oral cancers including oral squamous cell carcinoma, salivary gland cancers, and to highlight the most common cancer stem cell markers which have potential to be exploited as indicators for the preneoplastic lesion malignancy, oral cancer progression, and/or treatment prognosis.

MicroRNA-23a depletion promotes apoptosis of ovarian cancer stem cell and inhibits cell migration by targeting DLG2

Ovarian cancer (OC) is xenogeneic that is influenced by many generated factors related to epigenetic factors to accelerate tumor metastasis. This study was conducted with the objective of investigating the effect of microRNA-23a-3p (miR-23a) on the biological characteristics of OC stem cells by targeting discs large homolog 2 (DLG2). OC-related differentially expressed genes were screened by microarray-based gene expression analysis, after which a list of miRNAs that regulate the genes was predicted. In total, 50 patients diagnosed with OC were enrolled in this study. DLG2 positive protein expression was measured in OC tissues. The interaction between DLG2 and miR-23a was predicted and analyzed through luciferase activity measurement. With the intervention of miR-23a and/or DLG2 expression in OC stem cells, the expression of miR-23a, DLG2, Bax, Bcl-2, Oct-4, and Nanog was determined. Afterward, different cell experiments were conducted to examine the regulation effect of miR-23a in OC stem cells. Tumor formation in vivo was also evaluated in nude mice. DLG2 had low expression in OC. The results showed that there was a decrease in the expression of Bcl-2, Oct-4, and Nanog, while DLG2 and Bax were increased as a result of miR-23a depletion. In addition, when miR-23a was suppressed, cell viability, migration, invasion, cloning, and renewal abilities of OC stem cells were decreased, while apoptosis ability was enhanced. As a target gene of miR-23a, DLG2 downregulation reversed the suppressive function of miR-23a in the inhibition of OC development. Finally, in vivo experiment verified that miR-23a downregulation restrained the tumor growth in OC stem cells. In conclusion, our findings suggested that the inhibition of miR-23a results in the suppression of OC progression by releasing DLG2, which provides new understanding on the potential therapeutic effect of miR-23a inhibition in OC patients.