Radiosensitivity Of Cervical Cancer Research Articles

HDAC1 suppresses radiotherapy sensitivity in cervical cancer via regulating HIF-1α/VEGF signaling pathway.

Cervical cancer (CC) is the fourth most common cancer amongst females worldwide. Histone deacetylase (HDAC) 1 plays a vital role in several tumors. Nevertheless, its potential and mechanism in radiotherapy sensitivity underlying CC remains obscure. Hence, the objective of this research was to probe the potential of HDAC1 in CC radiotherapy sensitivity and its mechanism of action. The expression HDACs and survival analysis of HDAC1 were investigated based on the GEPIA database. Immunohistochemical staining was implemented to detect HDAC1 and Ki-67 expression in tumor tissues. RT-qPCR and Western blot were conducted to assess HDAC1, HIF-1α, VEGFA, along with VEGFR expressions in CC cells and tumor tissues. Cell viability, apoptosis, invasion, migration, along with cell cycle were analyzed by functional assays. Tumor-bearing nude mice model was established, and the tumor weight and volume were determined. HDAC1 was high-expressed in the tumor tissue and CC cells. In vitro, overexpression of HDAC1 suppressed radiotherapy sensitivity in C33A cells, while knockdown of HDAC1 promoted radiotherapy sensitivity in SiHa cells. In vivo, we found that HDAC1 silence hindered tumor growth and cell proliferation and promoted tumor cell apoptosis in nude mice after radiotherapy. In addition, we found that HDAC1 impacted radiotherapy sensitivity by modulating the HIF-1α/VEGF signaling pathway. In conclusion, HDAC1 suppressed the radiotherapy sensitivity of CC via regulating HIF-1α/VEGF signaling pathway, suggesting that HDAC1 may act as a crucial participant in regulating CC radiosensitivity, which may provide a novel method for treating CC.

Hypoxic tumor cell-derived small extracellular vesicle miR-152-3p promotes cervical cancer radioresistance through KLF15 protein

BackgroundRadiotherapy is widely used in treating cervical cancer patients, however, radioresistance unavoidably occurs and seriously affects the treatment effect. It is well known that hypoxia plays an important role in promoting radioresistance in tumor microenvironment, yet our understanding of the effect of small extracellular vesicles miRNA on cervical cancer radiosensitivity in hypoxic environment is still limited.MethodsSmall extracellular vesicles extracted from hypoxic and normoxic cultured cervical cancer cells were evaluated for their effects on radioresistance. miR-152-3p was found to be a potential effector in hypoxia-derived extracellular vesicles by searching the GEO database. Its downstream substrate was confirmed by double luciferase report, which was KLF15. The role of miR-152-3p and KLF15 in regulating cervical cancer radioresistance was detected by cell activity assays. The findings were confirmed in vivo by animal models. The expression of miR-152-3p was quantified by qRT-PCR and its prognostic significance was evaluated.ResultsHypoxic environment promoted the secretion of small extracellular vesicles, and reduced the apoptosis and DNA damage caused by radiation, accompanied by increased expression of small extracellular vesicles miR-152-3p from hypoxic cervical cancer cells. Furthermore, small extracellular vesicles miR-152-3p promoted Hela xenograft growth and reduced the radiosensitivity vivo. Mechanism studies revealed that KLF15 protein was the downstream target of miR-152-3p in regulating radioresistance.ConclusionOur findings suggest that small extracellular vesicles miR-152-3p affects the therapeutic effect of radiotherapy and holds potential as a biomarker or therapeutic target for cervical cancer prognosis and improving radiotherapy.

CircRNF13, a novel N6-methyladenosine-modified circular RNA, enhances radioresistance in cervical cancer by increasing CXCL1 mRNA stability

BackgroundCircular RNAs (circRNAs) and N6-methyladenosine (m6A) have been shown to play an increasingly critical role in the development of different cancers. However, there is limited evidence on how circRNAs and m6A interact to affect the radiosensitivity of cervical cancer (CC). This study provides a mechanistic understanding of the novel m6A-regulated circRNF13 in enhancing radioresistance in CC.MethodsDifferentially expressed circRNAs were identified from radiosensitive and radioresistant CC tissues. Meanwhile, these circRNAs were subjected to methylated RNA immunoprecipitation (Me-RIP). Finally, the effects of these circRNAs on radiosensitivity were characterized.ResultsCircRNF13 was poorly expressed in CC patients that were sensitive to concurrent radiochemotherapy. Experiments conducted both in vitro and in vivo confirmed that the knockdown of circRNF13 potentiated the radiosensitivity of CC cells. Further mechanistic studies revealed that METTL3/YTHDF2 promoted the degradation of circRNF13 and subsequently affected the stability of CXC motif chemokine ligand 1 (CXCL1), ultimately enhancing the radiosensitivity of CC cells.ConclusionThis study identified circRNF13 as a novel m6A-modified circRNA and validated the METTL3/YTHDF2/circRNF13/CXCL1 axis as a potential target for CC radiotherapy.

Cancer-Associated Fibroblasts Exposed to High-Dose Ionizing Radiation Promote M2 Polarization of Macrophages, Which Induce Radiosensitivity in Cervical Cancer

Radiotherapy, including brachytherapy, is a major therapeutic regimen for cervical cancer. Radioresistance is a decisive factor in radiation treatment failure. Tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) in the tumor microenvironment are critical factors in the curative effects of cancer therapies. However, the interactions between TAMs and CAFs in the context of ionizing radiation are not fully understood. This study was undertaken to investigate whether M2 macrophages induce radioresistance in cervical cancer and to explore the TAMs' phenotypic transformation after IR and its underlying mechanisms. The radioresistance of cervical cancer cells was enhanced after being co-cultured with M2 macrophages. TAMs tended to undergo M2 polarization after high-dose irradiation, which was strongly associated with CAFs in both mouse models and patients with cervical cancer. Additionally, cytokine and chemokine analysis was performed to find that high-dose irradiated CAFs promoted macrophage polarization towards the M2 phenotype through chemokine (C-C motif) ligand 2. Collectively, our results highlight the crucial role that high-dose irradiated CAFs play in the regulation of M2 phenotype polarization, which ultimately induces radioresistance in cervical cancer.

Insights into the characteristics of primary radioresistant cervical cancer using single-cell transcriptomics

Radioresistance is a major cause of radiotherapy failure among patients with cervical cancer (CC), the fourth most common cause of cancer mortality in women worldwide. Traditional CC cell lines lose intra-tumoral heterogeneity, posing a challenge for radioresistance research. Meanwhile, conditional reprogramming (CR) maintains intra-tumoral heterogeneity and complexity, as well as the genomic and clinical characteristics of original cells and tissues. Three radioresistant and two radiosensitive primary CC cell lines were developed under CR conditions from patient specimens, and their characteristics were verified via immunofluorescence, growth kinetics, clone forming assay, xenografting, and immunohistochemistry. The CR cell lines had homogenous characteristics with original tumor tissues and maintained radiosensitivity in vitro and in vivo, while also maintaining intra-tumoral heterogeneity according to single-cell RNA sequencing analysis. Upon further investigation, 20.83% of cells in radioresistant CR cell lines aggregated in the G2/M cell cycle phase, which is sensitive to radiation, compared to 38.1% of cells in radiosensitive CR cell lines. This study established three radioresistant and two radiosensitive CC cell lines through CR, which will benefit further research investigating radiosensitivity in CC. Our present study may provide an ideal model for research on development of radioresistance and potential therapeutic targets in CC.

O6-3 - The role of p62, an autophagy-related protein, as a marker of radiosensitivity in cervical cancer

O6-3 - The role of p62, an autophagy-related protein, as a marker of radiosensitivity in cervical cancer

Molecular mechanisms of long noncoding RNAs associated with cervical cancer radiosensitivity.

Despite advances in cervical cancer screening and human papilloma virus (HPV) vaccines, cervical cancer remains a global health burden. The standard treatment of cervical cancer includes surgery, radiation therapy, and chemotherapy. Radiotherapy (RT) is the primary treatment for advanced-stage disease. However, due to radioresistance, most patients in the advanced stage have an adverse outcome. Recent studies have shown that long noncoding RNAs (lncRNAs) participate in the regulation of cancer radiosensitivity by regulating DNA damage repair, apoptosis, cancer stem cells (CSCs), and epithelial-mesenchymal transition (EMT). In this review, we summarize the molecular mechanisms of long noncoding RNAs in cervical cancer and radiosensitivity, hoping to provide a theoretical basis and a new molecular target for the cervical cancer RT in the clinic.

HPV and radiosensitivity of cervical cancer: a narrative review.

Cervical cancer (CC), the most common gynecological malignancy, is divided into two categories: human papillomavirus-related [HPV positive (HPV+)] and non-HPV-related [HPV negative (HPV-)]. Compared with HPV- CC, HPV+ CC has better radiosensitivity and prognosis. We conducted a literature search and summarized relevant studies to explore the detailed mechanisms by which HPV+ improves the prognosis of CC compared to HPV-. PubMed was used to search the literature on human papillomavirus, cervical cancer, and radiotherapy up to June 2022. Compared with HPV- CC, HPV+ CC has better radiotherapy outcomes and better prognosis. HPV improves the radiotherapy sensitivity of CC by inhibiting damaged DNA repair, increasing cell cycle arrest, reducing hypoxia, increasing cellular immune response, and other mechanisms. However, the effect of HPV on radiotherapy sensitivity of CC is not consistent and is affected by HPV type, viral load, and many other factors. Partial HPV+ CCs, due to hypoxia and other factors, are resistant to radiotherapy and have a poor prognosis. HPV- CC has poor radiotherapy sensitivity and poor prognosis. With the spread of the vaccine, HPV- CC will gradually increase, which is a cause for concern. The radiosensitivity was significantly increased in patients with HPV+ CC, compared to HPV- patients. HPV improves the radiotherapy sensitivity of cervical cancer through a number of pathways. Meanwhile, the relationship between HPV and radiotherapy sensitivity is influenced by a number of factors. Some HPV+ CCs showed radiotherapy resistance, and HPV- CCs deserve further attention.

OP-18 - SQSTM1/p62 might be involved in radio-sensitivity of HPV-infected cervical cancer cells

Most cervical cancers are caused by human papillomavirus (HPV) infection. There have been several reports for the association between HPV infection and p62 expression. However, an adjuvant therapy targeting p62 has not been established. This study was conducted to clarify the possibility for enhancing the radio-sensitivity in cervical cancers by the p62-target therapy. We evaluated the expressions of autophagy relative proteins (p62, p-p62, LC3) in HeLa cells (HPV type 18), ME180 (HPV type 68) and C33A (HPV negative) by immunohistochemistry and western blotting. Survival after irradiation was evaluated by WST-1. We also examined the alternations of radio-sensitivity by p62 knockdown or chemical autophagy inhibitors. The expression of p62 was stronger in the cervical cancer tissues, compared to CIN. The p62 expression level was significantly higher in the HPV-positive cell lines, compared to the HPV-negative cell. Addition of CQ did not result in increased expression of p62. The expression of p62 was higher in the HPV-positive cells than that in the HPV-negative cells in the presence of Baf. Baf also increased the expression of phosphorylated p62 in the cells regardless of HPV infection. Addition of Baf increased radiosensitivity in all cells. In contrast, the addition of CQ did not affect radio-sensitivity in HPV-positive cell lines. Finally, p62 knockdown eliminated the radio-sensitivity in ME180 cells. p62 can be associated with radio-sensitivity of cervical cancer, and some autophagy inhibitors may be useful for the adjuvant therapy to increase the radio-sensitivity.

PRKCI Mediates Radiosensitivity via the Hedgehog/GLI1 Pathway in Cervical Cancer.

ObjectiveInsensitivity to radiotherapy accounts for the majority of therapeutic failures in cervical cancer (CC) patients who undergo radical radiotherapy. We aimed to elucidate the molecular mechanisms underlying radiosensitivity to identify methods to improve the overall 5-year survival rate. The atypical protein kinase C iota (aPKCι) gene PRKCI exhibits tumor-specific copy number amplification (CNA) in CC. We investigated how PRKCI decreases radiosensitivity in CC and assessed the interplay between PRKCI and the Hedgehog (Hh)/GLI1 pathway in the present research.MethodsThe biological functions of PRKCI in CC radiosensitivity were explored through immunohistochemistry, colony formation, Cell Counting Kit-8 (CCK-8), cell cycle, apoptosis assays, and xenograft models. qRT-PCR, Western blotting analysis, and immunofluorescence assays were utilized to evaluate the interplay between PRKCI and the Hh/GLI1 pathway and its mechanism in PRKCI-decreased radiosensitivity in CC. Furthermore, the effect of auranofin (AF), a selective inhibitor of PKCι, on CC cells was explored through biochemical assays in vitro and in vivo.ResultsWe found that high PRKCI expression was responsible for decreased survival in CC. PRKCI was intimately associated with radiation-triggered alterations in proliferation, the cell cycle, apoptosis, and xenograft growth. The Hh/GLI1 pathway was activated when PRKCI expression was altered. PRKCI functions downstream of the Hh/GLI1 pathway to phosphorylate and activate the transcription factor GLI1. AF acts as a radiosensitizer and showed biological effects in vitro and in vivo.ConclusionsPRKCI is a therapeutic target for regulating radiosensitivity in CC. This molecule regulates radiosensitivity by modulating GLI1 relocalization and phosphorylation in CC via the Hh/GLI1 pathway.

ZNF582 promoter methylation predicts cervical cancer radiosensitivity and ZNF582 protein overexpression reduces radiosensitivity by cell cycle arrest in S phase

ABSTRACT This study aimed to investigate the relationship between ZNF582 promoter methylation (ZNF582m ) level and radiosensitivity of cervical cancer and its biological basis. This was a prospective multicenter clinical study, comprising two independent cohorts of locally advanced cervical cancer patients. Exfoliated cervical cells were collected at 0, 24, 30, 36, 48, and 64 Gy to test ZNF582m levels. Radiotherapy response was evaluated according to RECIST Version. RT-PCR and WT were used to detect the mRNA and protein expression levels; MTT and flow cytometry were used to detect the cell viability and cell cycle, respectively. While clone formation and subcutaneous tumorigenesis in nude mice were used to detect the growth of HeLa cells with/without ZNF582 overexpression. In the first cohort, 22 cases achieved complete remission (CR) or partial response (PR), and the other 28 cases exhibited stable disease (SD). Radiotherapy reduced ZNF582m levels among all patients. Initial lever of ZNF582m was significantly higher in the Responder (CR + PR) group than in the SD group. Also, patients with higher initial lever ZNF582m were more sensitive towards radiotherapy than ZNF582m- low patients. The second cohort confirmed the above results. The amplitude of ZNF582m levels were related to the radiotherapeutic response; some patients of ZNF582m- low showed a transient increase in ZNF582m , and present greater radiosensitivity than other ZNF582m- low patients. In vitro, ZNF582 protein overexpression promoted cell cycle arrest in S phase. These results suggested that higher ZNF582m levels predicted greater radiosensitivity in clinical cervical cancer cases. Overexpressed ZNF582 conferred radioresistance by cell cycle arrest in vitro.

Retraction Note to: LncRNA SNHG12 regulates the radiosensitivity of cervical cancer through the miR-148a/CDK1 pathway

Retraction Note to: LncRNA SNHG12 regulates the radiosensitivity of cervical cancer through the miR-148a/CDK1 pathway

The Role of LncRNAs in the Regulation of Radiotherapy Sensitivity in Cervical Cancer.

Cervical cancer (CC) is one of the three majors gynecological malignancies, which seriously threatens women’s health and life. Radiotherapy (RT) is one of the most common treatments for cervical cancer, which can reduce local recurrence and prolong survival in patients with cervical cancer. However, the resistance of cancer cells to Radiotherapy are the main cause of treatment failure in patients with cervical cancer. Long non-coding RNAs (LncRNAs) are a group of non-protein-coding RNAs with a length of more than 200 nucleotides, which play an important role in regulating the biological behavior of cervical cancer. Recent studies have shown that LncRNAs play a key role in regulating the sensitivity of radiotherapy for cervical cancer. In this review, we summarize the structure and function of LncRNAs and the molecular mechanism of radiosensitivity in cervical cancer, list the LncRNAs associated with radiosensitivity in cervical cancer, analyze their potential mechanisms, and discuss the potential clinical application of these LncRNAs in regulating radiosensitivity in cervical cancer.

Everolimus (RAD001) combined with programmed death-1 (PD-1) blockade enhances radiosensitivity of cervical cancer and programmed death-ligand 1 (PD-L1) expression by blocking the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR)/S6 kinase 1 (S6K1) pathway

ABSTRACT Cervical cancer (CC) is the 4th most prevalent malignancy in females. This study explored the mechanism of everolimus (RAD001) combined with programmed death-1 (PD-1) blockade on radiosensitivity by phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway and autophagy in CC cells. Low-radiosensitive CaSki cells were selected as study objects. After RAD001 treatment, PI3K/AKT/mTOR pathway activation, autophagy, migration and invasion abilities, autophagy-related proteins (LC3-I, LC3-II, and p62), and PD-L1 expression in CC cells were detected. After triple treatment of radiotherapy (RT), RAD001, and PD-1 blockade to the CC mouse models, tumor weight and volume were recorded. Ki67 expression, the number of CD8 + T cells, and the ability to produce IFN-γ and TNF-α in tumor tissues were determined. RAD001 promoted autophagy by repressing PI3K/AKT/mTOR pathway, augmented RT-induced apoptosis, and weakened migration and invasion, thereby increasing CC cell radiosensitivity. RAD001 elevated RT-induced PD-L1 level. RT combined with RAD001 and PD-1 blockade intensified the inhibitory effect of RT on tumor growth, reduced the amount of Ki67-positive cells, enhanced radiosensitivity of CC mice, and increased the quantity and killing ability of CD8 + T cells. Briefly, RAD001 combined with PD-1 blockade increases radiosensitivity of CC by impeding the PI3K/AKT/mTOR pathway and potentiating cell autophagy.

Exosome-Mediated Transfer of miR-1323 from Cancer-Associated Fibroblasts Confers Radioresistance of C33A Cells by Targeting PABPN1 and Activating Wnt/β-Catenin Signaling Pathway in Cervical Cancer.

Plenty of pieces of evidence suggest that the resistance to radiotherapy greatly influences the therapeutic effect in cervical cancer (CCa). MicroRNAs (miRNAs) have been reported to regulate cellular processes by acting as tumor suppressors or promoters, thereby driving radioresistance or radiosensitivity. Meanwhile, it has been reported that microRNA-1323 (miR-1323) widely participates in cancer progression and radiotherapy effects. However, the role of miR-1323 is still not clear in CCa. Hence, in this study, we are going to investigate the molecular mechanism of miR-1323 in CCa cells. In the beginning, miR-1323 was found aberrantly upregulated in CCa cells via RT-qPCR assay. Functional assays indicated that miR-1323 was transferred by cancer-associated fibroblasts-secreted (CAFs-secreted) exosomes and miR-1323 downregulation suppressed cell proliferation, migration, invasion, and increased cell radiosensitivity in CCa. Mechanism assays demonstrated that miR-1323 targeted poly(A)-binding protein nuclear 1 (PABPN1). Besides, PABPN1 recruited insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) to regulate glycogen synthase kinase 3 beta (GSK-3β) and influenced Wnt/β-catenin signaling pathway. Therefore, rescue experiments were implemented to validate that PABPN1 overexpression rescued the inhibited cancer development and radioresistance induced by the miR-1323 inhibitor. In conclusion, miR-1323 was involved in CCa progression and radioresistance which might provide a novel insight for CCa treatment.

USP21 regulates Hippo signaling to promote radioresistance by deubiquitinating FOXM1 in cervical cancer.

The ectopic expression of ubiquitin-specific peptidase 21 (USP21) is common in different types of cancer. However, its relationship with radio-sensitivity in cervical cancer (CC) remains unclear. In this study, we aimed to uncover the effect of USP21 on CC radio-resistance and its underlying mechanism. Our results showed that the expression of USP21 was markedly increased in CC tissues of radio-resistant patients and CC cells treated with radiation. Besides, knockdown of USP21 restrained the survival fractions, and facilitated apoptosis of CC cells in the absence or presence of radiation. Additionally, USP21 in combination with FOXM1 regulated the stability and ubiquitination of FOXM1. However, FOXM1 reversed the effects of USP21 knockdown on the radio-resistance of CC cells. Furthermore, FOXM1 knockdown activated the Hippo pathway by inhibiting the nuclear translocation of Yes-associated protein 1 (YAP1), and FOXM1 knockdown attenuated the radio-resistance of CC cells via inhibiting the Hippo-YAP1 pathway. USP21 activated the Hippo pathway by mediating FOXM1. Knockdown of USP21 enhanced the radio-sensitivity of CC cells in vivo. In summary, USP21 contributed to the radio-resistance of CC cells via FOXM1/Hippo signaling, and may serve as a promising target for radio-sensitizers in the radiotherapy of CC.

Research on Radiosensitivity of the Protein Kinase B Signaling Pathway in Cervical Cancer.

The main characteristics of cervical cancer are abnormal and uncontrolled cell proliferation, and it regulates cell growth, differentiation, and cell death through genetic and epigenetic changes. This paper mainly discusses the radiosensitivity of the cervical cancer protein kinase B signaling pathway and discusses the specific mechanisms that affect the occurrence and development of cervical cancer. In addition, this paper studies the effect of transient transfection knocking down the expression of TRIP4 in cervical cancer cells on the expression of key proteins in related signaling pathways and explores the mechanism of its specific effects and finds the mechanism of TRIP4's effect on cervical cancer radiosensitivity. The findings of this study show for the first time that knocking down TRIP4 inhibits cell viability by inhibiting the P13K/AKT and MAPK/ERK pathways, and this corresponds to the first part of the experimental results, which show that knocking down TRIP4 inhibits colony formation and increases apoptosis in HeLa and SiHa cells. Moreover, simultaneous inhibition of TRIP4 and hTERT proteins can increase the radiosensitivity of cervical cancer cells. These findings indicate that the inhibition of TRIP4 may be a new type of treatment that selectively targets the P13K/AKT and MAPK/ERK pathways and hTERT pathways in cervical cancer cells and provides a therapeutic option for the treatment of cervical cancer.

RETRACTED ARTICLE: LncRNA SNHG12 regulates the radiosensitivity of cervical cancer through the miR-148a/CDK1 pathway

BackgroundRadiation resistance is a major obstacle to the prognosis of cervical cancer (CC) patients. Many studies have confirmed that long non-coding RNAs (lncRNAs) are involved in the regulation of radiosensitivity of cancers. However, whether small nucleolar RNA host gene 12 (SNHG12) regulates the radiosensitivity of CC remains unknown.MethodsQuantitative real-time polymerase chain reaction was used to measure the expression levels of SNHG12 and microRNA-148a (miR-148a). The radiosensitivity of cells was evaluated by clonogenic assay. Flow cytometry and caspase-3 activity assay were performed to assess the apoptosis ability and cell cycle distribution of cells. Besides, dual-luciferase reporter and RNA immunoprecipitation assay were used to verify the interaction between miR-148a and SNHG12 or cyclin-dependent kinase 1 (CDK1). Also, the protein levels of CDK1, CCND1 and γ-H2AX were detected by western blot analysis. Furthermore, in vivo experiments were conducted to verify the effect of SNHG12 on CC tumor growth. Ki-67 and TUNEL staining were employed to evaluate the proliferation and apoptosis rates in vivo. The hematoxylin and eosin (HE) staining were employed to evaluate the tumor cell morphology.ResultsSNHG12 was upregulated in CC tissues and cells, and its knockdown improved the radiosensitivity by promoting the radiation-induced apoptosis and cell cycle arrest of CC cells. Also, miR-148a could be sponged by SNHG12 and could target CDK1. MiR-148a inhibitor or CDK1 overexpression could invert the promotion effect of silenced-SNHG12 on CC radiosensitivity. Meanwhile, SNHG12 interference reduced the tumor growth of CC, increased miR-148a expression, and inhibited CDK1 level in vivo.ConclusionLncRNA SNHG12 promoted CDK1 expression to regulate the sensitivity of CC cells to radiation through sponging miR-148a, indicating that SNHG12 could be used as a potential biomarker to treat the radiotherapy resistance of CC patients.

Aberrant methylation of GADD45A is associated with decreased radiosensitivity in cervical cancer through the PI3K/AKT signaling pathway.

Epigenetic inactivation of GADD45A is a common occurrence in different types of cancer. However, little is known regarding its association with radiosensitivity in cervical cancer (CC). Thus, the present study aimed to investigate the association between aberrant GADD45A methylation and radiosensitivity in CC. SiHa, HeLa and CaSki CC cells were treated with 5-azacytidine (5-azaC), with or without irradiation. The expression levels of GADD45A and AKT related molecules were detected via reverse transcription-quantitative PCR and western blot analyses. The methylation status of GADD45A was assessed via methylation-specific PCR and cell proliferation assays, while clonogenic assays and flow cytometric analysis were performed to assess the function of the genes (GADD45A and AKT) in the CC cell lines. The results demonstrated that methylation of GADD45A was significantly higher in the radioresistant tissues (63.16%) compared with the radiosensitive samples (33.33%). In addition, the surviving fraction of SiHa cells following irradiation with 2 Gy was demonstrated to be highest amongst the three CC cells (CaSki, 57±9.5%; HeLa, 70±4% and SiHa, 75±10%). The survival rate of SiHa cells following treatment with 5-azaC and ionizing radiation (IR) significantly decreased as the radiation dose increased, compared with treatment with IR alone. Following overexpression of GADD45A or treatment with 5-azaC, the radiosensitivity of SiHa cells significantly increased compared with both the control vector and PBS treated groups. In addition, the AKT inhibitor, MK-2206, increased the radiosensitivity of SiHa cells. Notably, aberrant methylation of GADD45A was associated with decreased radiosensitivity in CC, and the PI3K/AKT signaling pathway was essential for radioresistance, which was mediated through downregulation of GADD45A.

Knockdown of lncRNA PCAT1 Enhances Radiosensitivity of Cervical Cancer by Regulating miR-128/GOLM1 Axis.

PurposeCervical cancer (CC) is the fourth most common cancer with high death rate in females. The study aims to detect the mechanism of long non-coding RNA (LncRNA) PCAT1 on radiosensitivity of CC.MethodsThe expression of PCAT1, miR-128 and GOLM1 in CC tissues and cells was measured by qRT-PCR. Different doses of X-ray were used for radiation treatment of CC cells and 6 Gy was chosen to perform the following experiments. The proliferation, migration and invasion of CC cells were measured by MTT assay, wound healing assay and transwell assay, respectively. The target relationships among PCAT1, miR-128 and GOLM1 were predicted by StarBase and TargetScan and verified by luciferase reporter assay. The protein level of GOLM1 was determined by Western blot. The xenograft tumor model was constructed in nude mice to verify the effect of PCAT1 on radiosensitivity of CC in vivo.ResultsThe PCAT1 expression was upregulated in CC tissues and cells. PCAT1 silencing enhances radiosensitivity of CC cells on proliferation, migration and invasion. MiR-128 was the target of PCAT1 and was negatively regulated by PCAT1. Upregulation of miR-128 enhances radiosensitivity of CC cells on proliferation, migration and invasion. GOLM1 was a target of miR-128 and was negatively regulated by miR-128. Upregulation of GOLM1 and downregulation of miR-128 both reversed the enhanced effect of PCAT1 knockdown on radiosensitivity of CC cells, which partly promoted the proliferation, migration and invasion of CC cells.ConclusionSilencing of PCAT1 enhanced radiosensitivity of CC via targeting miR-128/GOLM1, which provided a new idea for treating CC.