Cervical Cancer Stem Research Articles

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

ABSTRACT 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.

MiR-92a-3p Promoted EMT via Targeting LATS1 in Cervical Cancer Stem Cells.

miR-92a-3p (microRNA-92a-3p) has been reported to be dysregulated in several cancers, and as such, it is considered to be a cancer-related microRNA. However, the influence of miR-92a-3p on biological behaviors in cervical cancer (CC) still remains unclear. Quantitative real-time PCR was used to detect miR-92a-3p levels in CC stem cells. Here, Cell Counting Kit-8 (CCK8) assay, Transwell cell invasion assay and flow cytometry assay were used to characterize the effects that miR-92a-3p and large tumor suppressor l (LATS1) had on proliferation, invasion and cell cycle transition. The luciferase reporter gene assay was used to verify the targeting relationship between miR-92a-3p and LATS1. Western Blotting was used to investigate the related signaling pathways and proteins. Data from The Cancer Genome Atlas (TCGA) showed that miR-92a-3p was upregulated in CC tissues and closely associated with overall survival. miR-92a-3p promoted proliferation, invasion and cell cycle transition in CC stem cells. The luciferase reporter assay showed that miR-92a-3p bound to the 3′-untranslated region (3′-UTR) of the LATS1 promoter. LATS1 inhibited proliferation, invasion and cell cycle transition. Results measured by Western Blotting showed that LATS1 downregulated expressions of transcriptional co-activator with PDZ-binding motif (TAZ), vimentin and cyclin E, but upregulated the expression of E-cadherin. Re-expression of LATS1 partly reversed the effects of miR-92a-3p on proliferation, invasion and cell cycle transition, as well as on TAZ, E-cadherin, vimentin, and cyclin E. miR-92a-3p promoted the malignant behavior of CC stem cells by targeting LATS1, which regulated TAZ and E-cadherin.

HK2 Is a Crucial Downstream Regulator of miR-148a for the Maintenance of Sphere-Forming Property and Cisplatin Resistance in Cervical Cancer Cells.

The acquisition of cancer stem-like properties is believed to be responsible for cancer metastasis and therapeutic resistance in cervical cancer (CC). CC tissues display a high expression level of hexokinase 2 (HK2), which is critical for the proliferation and migration of CC cells. However, little is known about the functional role of HK2 in the maintenance of cancer stem cell-like ability and cisplatin resistance of CC cells. Here, we showed that the expression of HK2 is significantly elevated in CC tissues, and high HK2 expression correlates with poor prognosis. HK2 overexpression (or knockdown) can promote (or inhibit) the sphere-forming ability and cisplatin resistance in CC cells. In addition, HK2-overexpressing CC cells show enhanced expression of cancer stem cell-associated genes (including SOX2 and OCT4) and drug resistance-related gene MDR1. The expression of HK2 is mediated by miR-145, miR-148a, and miR-497 in CC cells. Overexpression of miR-148a is sufficient to reduce sphere formation and cisplatin resistance in CC cells. Our results elucidate a novel mechanism through which miR-148a regulates CC stem cell-like properties and chemoresistance by interfering with the oncogene HK2, providing the first evidence that dysregulation of the miR-148a/HK2 signaling plays a critical role in the maintenance of sphere formation and cisplatin resistance of CC cells. Our findings may guide future studies on therapeutic strategies that reverse cisplatin resistance by targeting this pathway.

Bone Marrow Mesenchymal Stem Cell (BMSC) Exosomes Inhibit Angiogenesis and Enhance Autophagy Through Decreasing miR-21 in Cervical Cancer

We aimed to explore the mechanism underlying the role of miR-21 derived from bone marrow mesenchymal stem cell exosomes (BMSC-exos) in cervical cancer (CC) and the relation between angiogenesis and autophagy. In this study, BMSC-exos were co-cultured with CC stem cells followed by analysis of miR-21 expression by RT-qPCR, autophagy after hunger-induced feeding by Acridine Orange fluorescent staining, angiogenesis by tube formation assay. Co-culture of BMSC-exos effectively reduced miR-21 expression in CC stem cells and enhanced autophagy as demonstrated by upregulated Beclin1 and LC3B with assembly of autophagosome (p < 0.05), but the autophagy restored later. Moreover, in the presence of BMSC-exos, CC stem cell angiogenesis was suppressed by 79%. In conclusion, BMSC-exos enhance autophagy and inhibit angiogenesis in CC through decreasing miR-21, which provides a novel insight into etiology of CC.

Exosomal lncRNA UCA1 modulates cervical cancer stem cell self-renewal and differentiation through microRNA-122-5p/SOX2 axis

BackgroundThere is growing evidence discussing the role of long non-coding RNAs (lncRNAs) in cervical cancer (CC). We performed this study to explore the impact of exosomal lncRNA urothelial cancer-associated 1 (UCA1) in CC stem cells by sponging microRNA-122-5p (miR-122-5p) and regulating SOX2 expression.MethodsCC stem cells (CD133+CaSki) and exosomes were extracted and identified. The synthesized UCA1- and miR-122-5p-related sequences were transfected into CaSki cells, CaSki cells-derived exosomes were extracted and then co-cultured with CD133+CaSki cells. The functional roles of UCA1 and miR-122-5p in self-renewal and differentiation ability of CC stem cells were determined using ectopic expression, knockdown/depletion and reporter assay experiments. An in vivo experiment was performed to verify the in vitro results.ResultsUp-regulated UCA1 and SOX2 and down-regulated miR-122-5p were found in CaSki-Exo. Exosomes promoted invasion, migration, proliferation and restrained apoptosis of CD133+CaSki cells. Silencing UCA1 or up-regulating miR-122-5p degraded SOX2 expression, and reduced invasion, migration and proliferation of CD133+CaSki cells while advanced apoptosis and suppressed the tumor volume and weight in nude mice.ConclusionOur study provides evidence that CaSki-Exo can promote the self-renewal and differentiation ability of CC stem cells while silencing UCA1 or up-regulating miR-122-5p restrains self-renewal and differentiation of CC stem cells.

Elevated microRNA-130b-5p or silenced ELK1 inhibits self-renewal ability, proliferation, migration, and invasion abilities, and promotes apoptosis of cervical cancer stem cells.

Cervical cancer (CC) is the most familiar gynecological malignancy. With the poor prognosis of CC patients, this study explored the effect of microRNA (miR)-130b-5p targeting ELK1 expression on self-renewal ability and stemness of CC stem cells. The tissues of patients with CC or cervical benign lesions were collected. MiR-130b-5p and ELK1 expression was detected by reverse transcription quantitative polymerase chain reaction and western blot analysis. Human CC cell line Hela was cultured and the induced CC stem cells were introduced with miR-130b-5p mimic or silenced ELK1 to figure their roles in self-renewal ability, stemness, colony formation, proliferation, migration, invasion abilities, and apoptosis of CC stem cells. Tumor growth was detected in nude mice in vivo. The targeting relationship between miR-130b-5p and ELK1 was analyzed using bioinformatic prediction and dual luciferase reporter gene assay. Decreased miR-130b-5p and elevated ELK1 existed in CC tissues of patients. Up-regulated miR-130b-5p decreased ELK1 expression in CC stem cells. Elevated miR-130b-5p or silenced ELK1 inhibited self-renewal ability and stemness, colony formation, proliferation, migration and invasion abilities, promoted apoptosis of CC stem cells, as well as decreased the weight and volume of tumor in nude mice. ELK1 was found to be targeted by miR-130b-5p. Overexpression ELK1 effectively reversed the cellular phenotypic changes and tumor formation in vivo caused by up-regulation of miR-130b-5p. We conclude that up-regulated miR-130b-5p or silenced ELK1 inhibits CC stem cell growth.

Cervical cancer stem cell-associated genes: Prognostic implications in cervical cancer.

Cervical cancer is the fourth most common type of gynecological malignancy to affect females, worldwide. Although high-risk human papillomavirus (HR-HPV) infection is the primary etiologic agent associated with the development of cervical cancer, cancer stem cells (CSCs) also serve a prominent role in the development, metastasis, recurrence and prognosis of the disease. CSCs are a small subpopulation of cells that have the ability to self-renew and are present in the majority of tumors, including cervical cancer. Studies describing the phenotype of cervical CSCs (CCSCs) vary in their definition of the expression pattern of principal biomarkers, including Musashi-1, aldehyde dehydrogenase 1, Oct3/4, Sox2 and CD49f. However, these markers are not observed in all cancers, although several may be present in multiple tumor types. The present review describes the potential biomarkers of CSCs in cervical cancer. These CCSC biomarkers may serve as molecular targets to enhance the efficacy and reduce the side effects associated with chemotherapeutic treatment in HR-HPV-positive cervical cancer.

Doxycycline Induces Apoptosis and Inhibits Proliferation and Invasion of Human Cervical Carcinoma Stem Cells.

BackgroundCancer stem cells (CSCs) are proposed to be responsible for high recurrence rate in cervical carcinoma. Reagents that can suppress the proliferation and differentiation of CSCs would provide new opportunities to fight against tumor recurrence. Doxycycline has been reported as a potential anti-cancer compound. However, few studies investigated its inhibitory effect against cervical cancer stem cells.MethodsHeLa cells were cultured in cancer stem cell conditional media in a poly-hema-treated dish. In this non-adhesive culture system, HeLa cells were treated with cisplatin until some cells survived and formed spheroids, which were then collected and injected into the immunodeficient mice. Cisplatin was administered every three days for five times. The tumor xenografts with CSC enrichment were cultured in cancer stem cell specific medium again to form tumorsphere, which we called HeLa-CSCs. Expression of cancer stem cell markers in HeLa-CSCs was measured by flow cytometry and qPCR. HeLa-CSCs were then treated with doxycycline. Proliferation and differentiation rates were determined by the size of spheres formed in vitro and tumor formed in vivo.ResultsWe developed a new strategy to selectively enrich CSCs from human cervical carcinoma cell line HeLa, and these HeLa-CSCs are CD133+/CD49f+ cell populations with significantly enhanced expression of stem cell markers. When these HeLa-CSCs were treated with doxycycline, the colony formation, proliferation, migration and invasion, and differentiation were all suppressed. Meanwhile, stem cell markers SOX-2, OCT-4, NANOG, NOTCH and BMI-1 decreased in doxycycline treated cells, so as the surface markers CD133 and CD49f. Furthermore, proliferation markers Ki67 and PCNA were also decreased by doxycycline treatment in the in vivo xenograft mouse model.ConclusionsCancer stem cells are enriched from sphere-forming and chemoresistant HeLa-derived tumor xenografts in immunodeficient mice. Doxycycline inhibits proliferation, invasion, and differentiation, and also induces apoptosis of these HeLa-CSCs in vitro and in vivo.