Investigating the Role of Telomere and Telomerase Associated Genes and Proteins in Endometrial Cancer

A prognostic model for Schistosoma japonicum infection-associated liver hepatocellular carcinoma: strengthening the connection through initial biological experiments

BACKGROUND

Numerous studies have shown that Schistosoma japonicum infection correlates with an increased risk of liver hepatocellular carcinoma (LIHC). However, data regarding the role of this infection in LIHC oncogenesis are scarce. This study aimed to investigate the potential mechanisms of hepatocarcinogenesis associated with Schistosoma japonicum infection.

METHODS

By examining chronic liver disease as a mediator, we identified the genes contributing to Schistosoma japonicum infection and LIHC. We selected 15 key differentially expressed genes (DEGs) using weighted gene co-expression network analysis (WGCNA) and random survival forest models. Consensus clustering revealed two subgroups with distinct prognoses. Least Absolute Shrinkage and Selection Operator (LASSO) and Cox regression identified six prognostic DEGs, forming an Schistosoma japonicum infection-associated signature for strong prognosis prediction. This signature, which is an independent LIHC risk factor, was significantly correlated with clinical variables. Four DEGs, including BMI1, were selected based on their protein expression levels in cancerous and normal tissues. We confirmed BMI1's role in LIHC using Schistosoma japonicum-infected mouse models and molecular experiments.

RESULTS

We identified a series of DEGs that mediate schistosomiasis, the parasitic disease caused by Schistosoma japonicum infection, and hepatocarcinogenesis, and constructed a suitable prognostic model. We analyzed the mechanisms by which these DEGs regulate disease and present the differences in prognosis between the different genotypes. Finally, we verified our findings using molecular biology experiments.

CONCLUSION

Bioinformatics and molecular biology analyses confirmed a relationship between schistosomiasis and liver hepatocellular cancer. Furthermore, we validated the role of a potential oncoprotein factor that may be associated with infection and carcinogenesis. These findings enhance our understanding of Schistosoma japonicum infection's role in LIHC carcinogenesis.

TRMT13 inhibits the growth of papillary thyroid cancer by targeting ANAPC4

The recently discovered gene TRMT13 encodes a type of RNA methylase and is a member of the CCDC family (also called CCDC76). Here, we delineate its role in papillary thyroid cancer (PTC). Bioinformatics analysis shows significant TRMT13 and ANAPC4 downregulation in PTC and reveals that the expression levels of both genes are linearly correlated. Subsequent analyses confirm that both TRMT13 and ANAPC4 expressions are downregulated in PTC tissues and that this change in expression has a significant impact on cancer diagnosis. We conduct assays on PTC cells subjected to TRMT13 and ANAPC4 silencing or overexpression to assess the biological effects of these genes. We also perform rescue experiments to validate the regulatory effects of TRMT13 on ANAPC4. A nude mouse tumor model is used to evaluate the effects of TRMT13 and ANAPC4 on PTC tumorigenesis. TRMT13 expression is decreased in PTC tissues and cell lines and is positively correlated with that of ANAPC4. Cell assays reveal that TRMT13/ANAPC4 attenuates the malignancy of PTC cells by restraining cell proliferation, migration and invasion, while rescue experiments corroborate that ANAPC4 is a downstream target of TRMT13. In the nude mouse xenograft model, both TRMT13 and ANAPC4 inhibit tumor growth, and TRMT13 and ANAPC4 expression levels are significantly associated with survival. Taken together, these findings lead to the conclusion that TRMT13 inhibits PTC growth via ANAPC4, indicating a new role of TRMT13 and providing insights into the tRNA methyltransferase and coiled-coil domain-containing protein families.

Detection of endometrial cancer using tampon-based collection and methylated DNA markers

OBJECTIVE

Alterations in DNA methylation are early events in endometrial cancer (EC) development and may have utility in EC detection via tampon-collected vaginal fluid.

METHODS

For discovery, DNA from frozen EC, benign endometrium (BE), and benign cervicovaginal (BCV) tissues underwent reduced representation bisulfite sequencing (RRBS) to identify differentially methylated regions (DMRs). Candidate DMRs were selected based on receiver operating characteristic (ROC) discrimination, methylation level fold-change between cancers and controls, and absence of background CpG methylation. Methylated DNA marker (MDM) validation was performed using qMSP on DNA from independent EC and BE FFPE tissue sets. Women ≥45 years of age with abnormal uterine bleeding (AUB) or postmenopausal bleeding (PMB) or any age with biopsy-proven EC self-collected vaginal fluid using a tampon prior to clinically indicated endometrial sampling or hysterectomy. Vaginal fluid DNA was assayed by qMSP for EC-associated MDMs. Random forest modeling analysis was performed to generate predictive probability of underlying disease; results were 500-fold in-silico cross-validated.

RESULTS

Thirty-three candidate MDMs met performance criteria in tissue. For the tampon pilot, 100 EC cases were frequency matched by menopausal status and tampon collection date to 92 BE controls. A 28-MDM panel highly discriminated between EC and BE (96% (95%CI 89-99%) specificity; 76% (66-84%) sensitivity (AUC 0.88). In PBS/EDTA tampon buffer, the panel yielded 96% (95% CI 87-99%) specificity and 82% (70-91%) sensitivity (AUC 0.91).

CONCLUSION

Next generation methylome sequencing, stringent filtering criteria, and independent validation yielded excellent candidate MDMs for EC. EC-associated MDMs performed with promisingly high sensitivity and specificity in tampon-collected vaginal fluid; PBS-based tampon buffer with added EDTA improved sensitivity. Larger tampon-based EC MDM testing studies are warranted.

Role of Nucleolin in Endometrial Precancerous Hyperplasia and Carcinogenesis: Ex Vivo and In Silico Study

Endometrial cancer (EC) is the most common gynaecological malignancy. Nucleolin (NCL) is involved in rDNA transcription, cell proliferation, and apoptosis, with high expression associated with worse overall survival (OS) in other adenocarcinomas. Our aims were to assess NCL gene and protein expression and explore the differential expression of NCL-associated genes (NAGs) in endometrial carcinogenesis. Endometrial samples were obtained from 157 women to include healthy, hyperplastic (EH), EC, and metastatic groups. RT-qPCR and immunohistochemistry were employed to assess NCL gene and protein levels. In silico analysis of NAGs in TCGA and GEO datasets was performed, with the prognostic value determined via Human Protein Atlas. NCL mRNA level of EC was lower than in healthy post-menopausal endometrium (p < 0.01). EH samples had lower NCL immuno-expression scores than healthy pre-menopausal (p < 0.001), benign post-menopausal (p < 0.01), and EC (p < 0.0001) samples. Metastatic lesions demonstrated higher NCL quick scores than primary tissue (p = 0.04). Higher NCL Immuno quick scores carried a worse OS in high-grade EC (p = 0.01). Interrogating Uterine Corpus Endometrial Carcinoma (TCGA-UCEC) and Uterine Carcinosarcoma (TCGA-UCS) cohorts revealed NCL to be the most highly upregulated gene in carcinosarcoma, with S100A11, LMNB2, RERG, E2F1 and CCNA2 representing key dysregulated NAGs in EC. Since NCL is implicated in transforming hyperplastic glands into cancer, with further involvement in metastasis, it is suggested to be a promising target for better-informed diagnosis, risk stratification, and management of EC.

Telomere and Telomerase-Associated Proteins in Endometrial Carcinogenesis and Cancer-Associated Survival

Risk of relapse of endometrial cancer (EC) after surgical treatment is 13% and recurrent disease carries a poor prognosis. Research into prognostic indicators is essential to improve EC management and outcome. "Immortality" of most cancer cells is dependent on telomerase, but the role of associated proteins in the endometrium is poorly understood. The Cancer Genome Atlas data highlighted telomere/telomerase associated genes (TTAGs) with prognostic relevance in the endometrium, and a recent in silico study identified a group of TTAGs and proteins as key regulators within a network of dysregulated genes in EC. We characterise relevant telomere/telomerase associated proteins (TTAPs) NOP10, NHP2, NOP56, TERF1, TERF2 and TERF2IP in the endometrium using quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC). qPCR data demonstrated altered expression of multiple TTAPs; specifically, increased NOP10 (p = 0.03) and reduced NHP2 (p = 0.01), TERF2 (p = 0.01) and TERF2IP (p < 0.003) in EC relative to post-menopausal endometrium. Notably, we report reduced NHP2 in EC compared to post-menopausal endometrium in qPCR and IHC (p = 0.0001) data; with survival analysis indicating high immunoscore is favourable in EC (p = 0.0006). Our findings indicate a potential prognostic role for TTAPs in EC, particularly NHP2. Further evaluation of the prognostic and functional role of the examined TTAPs is warranted to develop novel treatment strategies.

Mutual regulation between chicken telomerase reverse transcriptase and the Wnt/β-catenin signalling pathway inhibits apoptosis and promotes the replication of ALV-J in LMH cells

This study aimed to explore the mutual regulation between chicken telomerase reverse transcriptase (chTERT) and the Wnt/β-catenin signalling pathway and its effects on cell growth and avian leukosis virus subgroup J (ALV-J) replication in LMH cells. First, LMH cells stably overexpressing the chTERT gene (LMH-chTERT cells) and corresponding control cells (LMH-NC cells) were successfully constructed with a lentiviral vector expression system. The results showed that chTERT upregulated the expression of β-catenin, Cyclin D1, TCF4 and c-Myc. chTERT expression level and telomerase activity were increased when cells were treated with LiCl. When the cells were treated with ICG001 or IWP-2, the activity of the Wnt/β-catenin signalling pathway was significantly inhibited, and chTERT expression and telomerase activity were also inhibited. However, when the β-catenin gene was knocked down by small interfering RNA (siRNA), the changes in chTERT expression and telomerase activity were consistent with those in cells treated with ICG001 or IWP-2. These results indicated that chTERT and the Wnt/β-catenin signalling pathway can be mutually regulated. Subsequently, we found that chTERT not only shortened the cell cycle to promote proliferation but also inhibited apoptosis by downregulating the expression of Caspase 3, Caspase 9 and BAX; upregulating BCL-2 and BCL-X expression; and promoting autophagy. Moreover, chTERT significantly enhanced the migration ability of LMH cells, upregulated the protein and mRNA expression of ALV-J and increased the virus titre. ALV-J replication promoted chTERT expression and telomerase activity.

Endometriosis Is Associated with a Significant Increase in hTERC and Altered Telomere/Telomerase Associated Genes in the Eutopic Endometrium, an Ex-Vivo and In Silico Study

Telomeres protect chromosomal ends and they are maintained by the specialised enzyme, telomerase. Endometriosis is a common gynaecological disease and high telomerase activity and higher hTERT levels associated with longer endometrial telomere lengths are characteristics of eutopic secretory endometrial aberrations of women with endometriosis. Our ex-vivo study examined the levels of hTERC and DKC1 RNA and dyskerin protein levels in the endometrium from healthy women and those with endometriosis (n = 117). The in silico study examined endometriosis-specific telomere- and telomerase-associated gene (TTAG) transcriptional aberrations of secretory phase eutopic endometrium utilising publicly available microarray datasets. Eutopic secretory endometrial hTERC levels were significantly increased in women with endometriosis compared to healthy endometrium, yet dyskerin mRNA and protein levels were unperturbed. Our in silico study identified 10 TTAGs (CDKN2A, PML, ZNHIT2, UBE3A, MCCC2, HSPC159, FGFR2, PIK3C2A, RALGAPA1, and HNRNPA2B1) to be altered in mid-secretory endometrium of women with endometriosis. High levels of hTERC and the identified other TTAGs might be part of the established alteration in the eutopic endometrial telomerase biology in women with endometriosis in the secretory phase of the endometrium and our data informs future research to unravel the fundamental involvement of telomerase in the pathogenesis of endometriosis.

Human Endometrial Carcinogenesis Is Associated with Significant Reduction in Long Non-Coding RNA, TERRA

Telomeres are transcribed as long non-coding RNAs called TERRAs (Telomeric repeat containing RNA) that participate in a variety of cellular regulatory functions. High telomerase activity (TA) is associated with endometrial cancer (EC). This study aimed to examine the levels of three TERRAs, transcribed at chromosomes 1q-2q-4q-10q-13q-22q, 16p and 20q in healthy (n = 23) and pathological (n = 24) human endometrium and to examine their association with cellular proliferation, TA and telomere lengths. EC samples demonstrated significantly reduced levels of TERRAs for Chromosome 16p (Ch-16p) (p < 0.002) and Chromosome 20q (Ch-20q) (p = 0.0006), when compared with the postmenopausal samples. No significant correlation was found between TERRA levels and TA but both Ch-16p and Ch-20q TERRA levels negatively correlated with the proliferative marker Ki67 (r = -0.35, p = 0.03 and r = -0.42, p = 0.01 respectively). Evaluation of single telomere length analysis (STELA) at XpYp telomeres demonstrated a significant shortening in EC samples when compared with healthy tissues (p = 0.002). We detected TERRAs in healthy human endometrium and observed altered individual TERRA-specific levels in malignant endometrium. The negative correlation of TERRAs with cellular proliferation along with their significant reduction in EC may suggest a role for TERRAs in carcinogenesis and thus future research should explore TERRAs as potential therapeutic targets in EC.