Emerging Roles of Long Non-coding RNAs in Uterine Leiomyoma Pathogenesis: a Review

A comparative analysis of the impact of three distinct laparoscopic myomectomy techniques on ovarian reserve: a randomized clinical trial

PURPOSE

Laparoscopic myomectomy is one of the preferred surgical treatments for symptomatic uterine fibroids. This study aimed to compare the effects of laparoscopic myomectomy with temporary uterine artery occlusion (TUAO), permanent uterine artery occlusion (PUAO), and vasopressin injection (VPI) on ovarian reserve in women with symptomatic uterine leiomyomas.

METHODS

This randomized clinical trial (RCT) study was conducted on women with symptomatic uterine fibroids referred to Shahid Beheshti and Al-Zahra Hospitals in Isfahan, Iran, from January 2024 to July 2024. A total of 54 women were included, with 18 women in each group. The women were randomly grouped based on the used techniques of TUAO, PUAO, and VPI. Moreover, ovarian reserve marker, including anti-Mullerian hormone (AMH) level, were measured before and after surgery. This parameter was evaluated 3 months after surgery for all patients. Also, the amount of hemoglobin was measured before and after 24 h after surgery for participants in each method.

RESULTS

TUAO, PUAO and VPI laparoscopic myomectomy techniques had almost similar effects on ovarian reserve. The AMH level before the surgery in TUAO, PUAO, and VPI groups was reported as 3.87 ng/mL, 3.42 ng/mL, and 3.57 ng/mL, respectively. The AMH level (3 month) after the surgery was 3.78 ng/mL, 3.34 ng/mL and 3.48 ng/mL, respectively. No significant difference was reported between AMH levels among the methods before and after the surgery (P = 0.27, P = 0.12, and P = 0.29, respectively). The Hb level before the surgery in TUAO, PUAO, VPI was 11.23 g/dL, 11.55 g/dL and 11.67 g/dL, respectively. The Hb level after the surgery (24 h) was reported as 10.95 g/dL, 11.31 g/dL and 11.25 g/dL, respectively. No significant difference was reported between Hb levels among the methods before and after the surgery (P = 0.36, P = 0.31, and P = 0.13, respectively).

CONCLUSION

As the choice of technique may depend on the factors such as surgeon preference and patient-specific factors, findings of this study have important implications for women undergoing LM and also highlight the need for further studies on the long-term effects of these techniques on ovarian reserve with larger sample sizes.

The Effect of Race/Ethnicity and MED12 Mutation on the Expression of Long Non-Coding RNAs in Uterine Leiomyoma and Myometrium

The objective of this study was to elucidate the expression of long non-coding RNA (lncRNA) in leiomyomas (Lyo) and paired myometrium (Myo) and explore the impact of race and MED12 mutation. Fold change analysis (Lyo/paired Myo) indicated the expression of 63 lncRNAs was significantly altered in the mutated group but not in the non-mutated Lyo. Additionally, 65 lncRNAs exhibited an over 1.5-fold change in the Black but not the White group. Fifteen differentially expressed lncRNAs identified with next-generation sequencing underwent qRT-PCR confirmation. Compared with Myo, the expression of TPTEP1, PART1, RPS10P7, MSC-AS1, SNHG12, CA3-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was significantly higher, while the expression of ZEB2-AS1, LINC00957, and LINC01186 was significantly lower. Comparison of normal Myo with diseased Myo showed significant differences in the expression of several lncRNAs. Analysis based on race and Lyo MED12 mutation status indicated a significantly higher expression of RPS10P7, SNHG12, LINC01449, LINC02433, and LINC02624 in Lyo from Black patients. The expression of TPTEP1, PART1, RPS10P7, MSC-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was higher, while LINC01186 was significantly lower in the MED12-mutated group. These results indicate that Lyo are characterized by aberrant lncRNA expression, which is further impacted by race and Lyo MED12 mutation status.

COVID-19-The Shift of Homeostasis into Oncopathology or Chronic Fibrosis in Terms of Female Reproductive System Involvement

The COVID-19 pandemic caused by the SARS-CoV-2 coronavirus remains a global public health concern due to the systemic nature of the infection and its long-term consequences, many of which remain to be elucidated. SARS-CoV-2 targets endothelial cells and blood vessels, altering the tissue microenvironment, its secretion, immune-cell subpopulations, the extracellular matrix, and the molecular composition and mechanical properties. The female reproductive system has high regenerative potential, but can accumulate damage, including due to SARS-CoV-2. COVID-19 is profibrotic and can change the tissue microenvironment toward an oncogenic niche. This makes COVID-19 and its consequences one of the potential regulators of a homeostasis shift toward oncopathology and fibrosis in the tissues of the female reproductive system. We are looking at SARS-CoV-2-induced changes at all levels in the female reproductive system.

A View on Uterine Leiomyoma Genesis through the Prism of Genetic, Epigenetic and Cellular Heterogeneity

Uterine leiomyomas (ULs), frequent benign tumours of the female reproductive tract, are associated with a range of symptoms and significant morbidity. Despite extensive research, there is no consensus on essential points of UL initiation and development. The main reason for this is a pronounced inter- and intratumoral heterogeneity resulting from diverse and complicated mechanisms underlying UL pathobiology. In this review, we comprehensively analyse risk and protective factors for UL development, UL cellular composition, hormonal and paracrine signalling, epigenetic regulation and genetic abnormalities. We conclude the need to carefully update the concept of UL genesis in light of the current data. Staying within the framework of the existing hypotheses, we introduce a possible timeline for UL development and the associated key events—from potential prerequisites to the beginning of UL formation and the onset of driver and passenger changes.

Differential Expression of MED12-Associated Coding RNA Transcripts in Uterine Leiomyomas

Recent studies have demonstrated that somatic MED12 mutations in exon 2 occur at a frequency of up to 80% and have a functional role in leiomyoma pathogenesis. The objective of this study was to elucidate the expression profile of coding RNA transcripts in leiomyomas, with and without these mutations, and their paired myometrium. Next-generation RNA sequencing (NGS) was used to systematically profile the differentially expressed RNA transcripts from paired leiomyomas (n = 19). The differential analysis indicated there are 394 genes differentially and aberrantly expressed only in the mutated tumors. These genes were predominantly involved in the regulation of extracellular constituents. Of the differentially expressed genes that overlapped in the two comparison groups, the magnitude of change in gene expression was greater for many genes in tumors bearing MED12 mutations. Although the myometrium did not express MED12 mutations, there were marked differences in the transcriptome landscape of the myometrium from mutated and non-mutated specimens, with genes regulating the response to oxygen-containing compounds being most altered. In conclusion, MED12 mutations have profound effects on the expression of genes pivotal to leiomyoma pathogenesis in the tumor and the myometrium which could alter tumor characteristics and growth potential.

An integrative analysis of an lncRNA-mRNA competing endogenous RNA network to identify functional lncRNAs in uterine leiomyomas with RNA sequencing

Objective: To explore the functions of mRNAs and lncRNAs in the occurrence of uterine leiomyomas (ULs) and further clarify the pathogenesis of UL by detecting the differential expression of mRNAs and lncRNAs in 10 cases of UL tissues and surrounding normal myometrial tissues by high-throughput RNA sequencing. Methods: The tissue samples of 10 patients who underwent hysterectomy for UL in Lianyungang Maternal and Child Health Hospital from January 2016 to December 2021 were collected. The differentially expressed mRNAs (DEmRNAs) and lncRNAs (DElncRNAs) were identified and further analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The protein-protein interaction network (PPI) was constructed in Cytoscape software. Functional annotation of the nearby target cis-DEmRNAs of DElncRNAs was performed with the Database for Annotation, Visualization, and Integrated Discovery (DAVID) (https://david.ncifcrf.gov/). Meanwhile, the co-expression network of DElncRNA-DEmRNA was constructed in Cytoscape software. Results: A total of 553 DElncRNAs (283 upregulated DElncRNAs and 270 downregulated DElncRNAs) and 3,293 DEmRNAs (1,632 upregulated DEmRNAs and 1,661 downregulated DEmRNAs) were obtained. GO pathway enrichment analysis revealed that several important pathways were significantly enriched in UL such as blood vessel development, regulation of ion transport, and external encapsulating structure organization. In addition, cytokine-cytokine receptor interaction, neuroactive ligand-receptor interaction, and complement and coagulation cascades were significantly enriched in KEGG pathway enrichment analysis. A total of 409 DElncRNAs-nearby-targeted DEmRNA pairs were detected, which included 118 DElncRNAs and 136 DEmRNAs. Finally, we found that the top two DElncRNAs with the most nearby DEmRNAs were BISPR and AC012531.1. Conclusion: These results suggested that 3,293 DEmRNAs and 553 DElncRNAs were differentially expressed in UL tissue and normal myometrium tissue, which might be candidate-identified therapeutic and prognostic targets for UL and be considered as offering several possible mechanisms and pathogenesis of UL in the future.

Further characterization of tryptophan metabolism and its dysregulation in fibroids

OBJECTIVE

To determine the expression of enzymes in tryptophan (Trp) catabolism in fibroids and matched myometrium and determine the effects of race and mediator complex subunit 12 gene (MED12) mutation on their expression.

DESIGN

Experimental laboratory study.

SETTING

Academic research laboratory.

PATIENT(S)

Women of reproductive age who underwent hysterectomy while on no hormonal medications before surgery.

INTERVENTION(S)

Fibroids and matched myometrium were obtained from patients who underwent hysterectomy from different race or ethnic groups.

MAIN OUTCOME MEASURE(S)

The expression of enzymes in the Trp catabolic pathway, tryptophan transporters, and the cytochrome P450 1B1 gene (CYP1B1) in the fibroids and matched myometrium of women from different race and ethnic groups and in tumors bearing the MED12 mutation and tumors without the mutation was determined using quantitative reverse-transcription polymerase chain reaction. The levels of serotonin, kynurenic acid (KYNA), and nicotinamide adenine dinucleotide (NAD) were determined using enzyme-linked immunosorbent assay.

RESULT(S)

In fibroids, the expression of tryptophan hydroxylase 1 (TPH1), kynurenine amino transferase (KAT)2, large neutral amino acid transporter small subunit 2 (SLC7A8), and large neutral amino acid transporter small subunit 1 (SLC7A5) messenger RNA (mRNA) was high and that of kynureninase (KYNU) and tryptophanyl-tRNA ligase (WARS1) mRNA was low, with no changes in the expression of WARS2, kynurenine formamidase (AFMID), kynurenine 3-monooxygenase (KMO), KAT1, KAT3, and KAT4 compared with that in the matched myometrium (n = 81). The expression of CYP1B1 mRNA, a marker of the activation of the aryl hydrocarbon receptor, was higher in fibroids. Tumors bearing the MED12 mutation expressed higher levels of CYP1B1 and lower levels of WARS1, KAT1, KAT3, and KAT4 mRNAs compared with tumors without the MED12 mutation. Race or ethnicity affected the expression of KYNU, with tumors from African American and Hispanic patients expressing lower levels of KYNU mRNA compared with those from Caucasian patients. We also quantified the levels of serotonin, KYNA, and NAD, which are the end products of Trp catabolism. There were no significant differences in the levels of serotonin and KYNA, whereas the levels of NAD were lower in fibroids than in the paired myometrium. This reduction in the levels of NAD was independent of race or ethnicity.

CONCLUSION(S)

In addition to the expression of tryptophan 2,3-dioxygenase or indoleamine-pyrrole 2,3-dioxygenase, there was marked dysregulation in the expression of other enzymes in the Trp metabolic pathway and Trp transporters in fibroids. Both MED12 mutation status and race or ethnicity had selective effects on the expression of the components of this pathway. Additional functional studies are necessary to establish the physiologic significance of the tryptophan degradation pathway in the pathogenesis of fibroids and its potential as a target for novel therapies.

Long non-coding RNA HEIH: a novel tumor activator in multiple cancers

The last decade has witnessed the altered expression levels of long non-coding RNA HEIH in different types of cancer. More than half of the HEIH studies in cancer have been published within the last two years. To our knowledge, this is the first review to discuss very recent developments and insights into HEIH contribution to carcinogenesis. The functional role, molecular mechanism, and clinical significance of HEIH in human cancers are described in detail. The expression of HEIH is elevated in a broad spectrum of cancers, and its disorder contributes to cell proliferation, migration, invasion, and drug resistance of cancer cells through different underlying mechanisms. In addition, the high expression of HEIH is significantly associated with advanced tumor stage, tumor size and decreased overall survival, suggesting HEIH may function as a prognostic biomarker and potential therapeutic target for human cancers.