Potential role of cancer stem cells as biomarkers and therapeutic targets in cervical cancer

Highlighting the role of CD44 in cervical cancer progression: immunotherapy's potential in inhibiting metastasis and chemoresistance

Cervical cancer affects thousands of women globally with recurring high-risk HPV infections being at the centre of cervical pathology. Oncological treatment strategies are continually challenged by both chemoresistance and metastasis within patients. Although both work hand-in-hand, targeting their individual mechanisms could prove highly beneficial for treatment outcomes. Such targets include the metastatic-promoting stem cell marker, CD44, which is abundant in cervical cancer cells and is common to both chemoresistance and metastatic mechanisms. Seeing that many existing advanced-stage cervical cancer treatment regimes, such as platinum-based chemotherapy regimens, remain limited and are rarely curative, alternative treatment options within the field of immunology are being considered. The use of immune checkpoint inhibition therapy, which targets immune checkpoints, CTLA-4 and PD-1/PD-L1, has shown promise as an alternate standard of care for patients suffering from advanced-stage cervical cancer. Therefore, this review aims to assess whether immune checkpoint inhibition can mitigate the pathological effects of CD44-induced EMT, metastasis, and chemoresistance in cervical cancer patients.

Aldehyde dehydrogenase 1 family: A potential molecule target for diseases

Aldehyde dehydrogenase 1 (ALDH1), a crucial aldehyde metabolizing enzyme, has six family members. The ALDH1 family is expressed in various tissues, with a significant presence in the liver. It plays a momentous role in several pathophysiological processes, including aldehyde detoxification, oxidative stress, and lipid peroxidation. Acetaldehyde detoxification is the fundamental function of the ALDH1 family in participating in vital pathological mechanisms. The ALDH1 family can catalyze retinal to retinoic acid (RA) that is a hormone-signaling molecule and plays a vital role in the development and adult tissues. Furthermore, there is a need for further and broader research on the role of the ALDH1 family as a signaling molecule. The ALDH1 family is widely recognized as a cancer stem cell (CSC) marker and plays a significant role in the proliferation, invasion, metastasis, prognosis, and drug resistance of cancer. The ALDH1 family also participates in other human diseases, such as neurodegenerative diseases, osteoarthritis, diabetes, and atherosclerosis. It can inhibit disease progression by inhibiting/promoting the expression/activity of the ALDH1 family. In this review, we comprehensively analyze the tissue distribution, and functions of the ALDH1 family. Additionally, we review the involvement of the ALDH1 family in diseases, focusing on the underlying pathological mechanisms and briefly talk about the current status and development of ALDH1 family inhibitors. The ALDH1 family presents new possibilities for treating diseases, with both its upstream and downstream pathways serving as promising targets for therapeutic intervention. This offers fresh perspectives for drug development in the field of disease research.

Unveiling diagnostic and therapeutic strategies for cervical cancer: biomarker discovery through proteomics approaches and exploring the role of cervical cancer stem cells

Cervical cancer (CC) is a major global health problem and leading cause of cancer deaths among women worldwide. Early detection through screening programs has reduced mortality; however, screening compliance remains low. Identifying non-invasive biomarkers through proteomics for diagnosis and monitoring response to treatment could improve patient outcomes. Here we review recent proteomics studies which have uncovered biomarkers and potential drug targets for CC. Additionally, we explore into the role of cervical cancer stem cells and their potential implications in driving CC progression and therapy resistance. Although challenges remain, proteomics has the potential to revolutionize the field of cervical cancer research and improve patient outcomes.

A novel fluorescent dye selectively images and kills cancer stem cells by targeting mitochondria: Evidence from a cell line‑based zebrafish xenograft model

Numerous agents such as near-infrared dyes that are characterized by specialized cancer imaging and cytotoxicity effects have key roles in cancer diagnosis and therapy via molecularly targeting special biological tissues, organelles and processes. In the present study, a novel fluorescent compound was demonstrated to inhibit cancer cell proliferation in a zebrafish model with slight in vivo toxicity. Further studies demonstrated selective staining of cancer cells and even putative cancer stem cells via accumulation of the dye in the mitochondria of cancer cells, compared with normal cells. Moreover, this compound was also used to image cancer cells in vivo using a zebrafish model. The compound displayed no apparent toxicity to the host animal. Overall, the data indicated that this compound was worthy of further evaluation due to its low toxicity and selective cancer cell imaging and killing effects. It could be a useful tool in cancer research.

Cancer Stem Cells and Their Possible Implications in Cervical Cancer: A Short Review

Cervical cancer (CC) is the fourth most common type of gynecological malignancy affecting females worldwide. Most CC cases are linked to infection with high-risk human papillomaviruses (HPV). There has been a significant decrease in the incidence and death rate of CC due to effective cervical Pap smear screening and administration of vaccines. However, this is not equally available throughout different societies. The prognosis of patients with advanced or recurrent CC is particularly poor, with a one-year relative survival rate of a maximum of 20%. Increasing evidence suggests that cancer stem cells (CSCs) may play an important role in CC tumorigenesis, metastasis, relapse, and chemo/radio-resistance, thus representing potential targets for a better therapeutic outcome. CSCs are a small subpopulation of tumor cells with self-renewing ability, which can differentiate into heterogeneous tumor cell types, thus creating a progeny of cells constituting the bulk of tumors. Since cervical CSCs (CCSC) are difficult to identify, this has led to the search for different markers (e.g., ABCG2, ITGA6 (CD49f), PROM1 (CD133), KRT17 (CK17), MSI1, POU5F1 (OCT4), and SOX2). Promising therapeutic strategies targeting CSC-signaling pathways and the CSC niche are currently under development. Here, we provide an overview of CC and CCSCs, describing the phenotypes of CCSCs and the potential of targeting CCSCs in the management of CC.

ITGA7, CD133, ALDH1 are inter-correlated, and linked with poor differentiation, lymph node metastasis as well as worse survival in surgical cervical cancer

AIM

Integrin alpha 7 (ITGA7) regulates cancer stemness and metastasis in several malignancies, while its role in cervical cancer is obscure. Therefore, the current study aimed to investigate the correlation among ITGA7, cluster of differentiation 133 (CD133), and aldehyde dehydrogenase isoform 1 (ALDH1), as well as their relation to tumor features and survival in cervical cancer patients.

METHODS

A total of 133 surgical cervical cancer patients were enrolled. Tumor ITGA7, CD133, and ALDH1 expressions were determined by immunohistochemistry (IHC). Furthermore, the clinicopathological features, disease-free survival (DFS), and overall survival (OS) were collected.

RESULTS

ITGA7 expression positively related to CD133 expression (p = 0.040) and ALDH1 expression (p < 0.001). Besides, ITGA7 (p = 0.001), CD133 (p = 0.016), and ALDH1 (p = 0.009) high expressions linked with poor tumor differentiation; meanwhile, ITGA7 (p = 0.010) and ALDH1 (p = 0.004) high expressions correlated with more prevalence of lymph node metastasis. However, ITGA7, CD133, or ALDH1 expression was not associated with other clinicopathological features. Inspiringly, it was worth noting that ITGA7 (p = 0.009), CD133 (p = 0.041), and ALDH1 (p = 0.035) high expressions predicted unfavorable DFS; meanwhile, both ITGA7 (p = 0.021) and ALDH1 (p = 0.023) high expressions but not CD133 expression (p = 0.169) forecasted exasperated OS.

CONCLUSION

ITGA7, CD133, ALDH1 are inter-correlated, and linked with poor differentiation, lymph node metastasis as well as worse survival in surgical cervical cancer.

Gynecologic Cancer, Cancer Stem Cells, and Possible Targeted Therapies

Gynecologic cancer is one of the main causes of death in women. In this type of cancer, several molecules (oncogenes or tumor suppressor genes) contribute to the tumorigenic process, invasion, metastasis, and resistance to treatment. Based on recent evidence, the detection of molecular changes in these genes could have clinical importance for the early detection and evaluation of tumor grade, as well as the selection of targeted treatment. Researchers have recently focused on cancer stem cells (CSCs) in the treatment of gynecologic cancer because of their ability to induce progression and recurrence of malignancy. This has highlighted the importance of a better understanding of the molecular basis of CSCs. The purpose of this review is to focus on the molecular mechanism of gynecologic cancer and the role of CSCs to discover more specific therapeutic approaches to gynecologic cancer treatment.

MACC1 regulates the AKT/STAT3 signaling pathway to induce migration, invasion, cancer stemness, and suppress apoptosis in cervical cancer cells

Cervical cancer (CC) ranks as the second most frequent tumor in women, and CC stem cells have been vital in the tumorigenesis of CC. Recently, the metastasis- associated in colon cancer 1 (MACC1) gene was proven to be a promising biomarker of CC. However, the role and mechanism of MACC1 in CC remain undetermined. Expressions of MACC1 were estimated by qRT-PCR, immunohistochemistry, and Western blot assays in cervical cancer tissues and cells. Three siRNAs were generated to knockdown expressions of MACC1 in CC cells. After knockdown of MACC1 or/and Colivelin treatment, cell migration, invasion, apoptosis, and stemness were evaluated through a series of functional experiments including Transwell, flow cytometry, Hoechst staining, and sphere-formation assays. MACC1 was found to express more highly in CC tissues in comparison with corresponding non-tumor tissues at both mRNA and protein levels. Functionally, the knocking- down of MACC1 significantly repressed migration and invasion, and induced apoptosis of CC cells. Also, knockdown of MACC1 was discovered to suppress sphere-formation of CC cells and downregulate OCT4 and Nanog. It was proved that knockdown of MACC1 had a significant blocking effect on the AKT/STAT3 pathway. In addition, we verified that treatment with the STAT3 activator (Colivelin) had significant reversal effects on the malignant behaviors of CC cells and CC stemness. Our study concluded that MACC1 might be a novel regulator of CC by regulating the AKT/STAT3 pathway to change the migration, invasion, apoptosis, and cancer stemness of CC cells.

SOX2 as a prognostic marker and a potential molecular target in cervical cancer: A meta-analysis

BACKGROUND

Sex determining region Y-box 2 (SOX2) has been reported as a potential therapeutic target for cancer. However, the role of SOX2 in cervical cancer remains largely undetermined. This study was performed to evaluate the correlation of SOX2 with clinical characteristics and prognosis in cervical cancer.

METHODS

Multiple databases were systematically searched for eligible publications. The combined odds ratios (ORs) or hazard ratios (HRs) with the corresponding 95% confidence intervals (CIs) were used to assess the effect sizes.

RESULTS

A total of 17 studies with 1906 participants were identified. SOX2 expression was higher in cervical cancer than in the normal control group (OR = 10.83, 95% CI = 6.64-17.67, P < 0.001), while no significant difference was observed between cervical cancer and cervical intraepithelial neoplasia. SOX2 expression was not associated with age, tumor stage, and lymph node metastasis, but was correlated with tumor grade (grade 2-3 vs. grade 1: OR = 4.59, 95% CI = 2.76-7.62, P < 0.001) and tumor size (≥4 cm vs. ≤4 cm: OR = 1.66, 95% CI = 1.05-2.60, P = 0.028). Based on multivariate Cox analysis, SOX2 expression was not correlated with overall survival, but was closely associated with poor recurrence-free survival (HR = 5.83, 95% CI = 1.35-25.16, P = 0.018) and progress-free survival HR = 2.29, 95% CI = 1.01-5.19, P = 0.046).

CONCLUSION

SOX2 may serve as a novel prognostic factor and a promising molecular target for cervical cancer.

PIWI proteins and piRNAs in cervical cancer: a propitious dart in cancer stem cell-targeted therapy

Any form of cancer is a result of uncontrolled cell growth caused by mutations and/or epigenetic alterations, implying that a balance of chromatin remodeling activities and epigenetic regulators is crucial to prevent the transformation of a normal cell to a cancer cell. Many of the chromatin remodelers do not recognize any specific sites on their targets and require guiding molecules to reach the respective targets. PIWI proteins and their interacting small non-coding RNAs (piRNAs) have proved to act as a guiding signal for such molecules. While epigenetic alterations lead to tumorigenesis, the stemness of cancer cells contributes to recurrence and metastasis of cancer. Various studies have propounded that the PIWI-piRNA complex also promotes stemness of cancer cells, providing new doors for target-mediated anti-cancer therapies. Despite the progress in diagnosis and development of vaccines, cervical cancer remains to be the second most prevalent cancer among women, due to the lack of cost-effective and accessible diagnostic and prevention methods. With the emergence of liquid biopsy, there is a significant demand for the ideal biomarker in the diagnosis of cancer. PIWI and piRNAs have been recommended to serve as prognostic and diagnostic markers, to differentiate early and later stages of cancer, including cervical cancer. This review discusses how PIWIs and piRNAs are involved in disease progression as well as their potential role in diagnostics and therapeutics in cervical cancer.

Potential role of cancer stem cells as biomarkers and therapeutic targets in cervical cancer

BACKGROUND

Eradicating cancer stem cells (CSCs) that are termed as the "beating heart" of various malignant tumors, including cervical cancer, holds great importance in cancer therapeutics. CSCs not only confer chemo-radio resistance but also play an important role in tumor metastasis and thereby pose a potential barrier for the cure of cervical cancer. Cervical cancer, a common malignancy among females, is associated with high morbidity and mortality rates, and the study on CSCs residing in the niche is promising.

RECENT FINDINGS

Biomarker approach to screen the cervical CSCs has gained impetus since the past decade. Progress in identification and characterization of the stem cell biomarkers has led to many insights. For the diagnostic purpose, several biomarkers like viral (HPV16), stem cell markers, transcription factors (viz, SOX2, OCT 4, and c-Myc), and CSC surface markers (viz, ALDH1 and CD44) have been identified. The research so far has been directed to study the CSC stemness and demonstrates various gene expression signatures in cervical CSCs. Such studies hold a potential to improve diagnostic accuracy and predict therapeutic response and clinical outcome in patients.

CONCLUSIONS

Stem cell biomarkers have been validated and their therapeutic targets are being developed as "strategies to improve therapeutic ratio in personalized medicine." This review gives a brief overview of the cervical CSC biomarkers, their current and future diagnostic, prognostic, and therapeutic potential.