HOXA11 and MMP2 gene expression in uterosacral ligaments of women with pelvic organ prolapse

Unveiling the depths of pelvic organ prolapse: From risk factors to therapeutic methods (Review)

Pelvic organ prolapse (POP) is a condition where one or more pelvic organs (such as the uterus, bladder and rectum) descend from their normal anatomical positions into the vagina, primarily due to the weakening of the pelvic floor support structures. While not life-threatening, POP can substantially diminish the patient's quality of life and lead to serious social and psychological complications. Researchers have explored novel directions regarding the etiology, mechanism and treatment of POP. However, existing literature on the subject often lacks comprehensive and systematic overviews. To address this gap and enhance researchers' understanding of POP, the present study reviewed the risk factors and molecular mechanisms of POP [including matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs, transforming growth factor β, advanced glycation end products (AGEs)/receptor for AGE, phosphoinositide 3-kinase/protein kinase B, fibulin, lysyl oxidase-like 1, homeobox A11, collagen α-1 (XVIII) chain, Wnt signaling pathways and estrogen receptor α], as well as therapeutic approaches, such as lifestyle interventions, physical methods, pharmacotherapy, stem cell transplantation and surgical techniques. The present review aims to provide new insights for future research and contribute to the advancement of diagnosis and treatment strategies for POP.

Genetic Etiology in Pelvic Organ Prolapse: Role of Connective Tissue Homeostasis, Hormone Metabolism, and Oxidative Stress

Background: Pelvic organ prolapse (POP) has become a common health problem among the aging population and affects an increasing number of elderly women worldwide. Studies within family and twin pairs provided strong evidence for the contribution of genetic factors to POP. Given the incomplete penetrance, polygenic traits, and small effect sizes of each variant in complex diseases, it is not always easy to evaluate the genetic susceptibility and molecular mechanisms involved in POP. Objectives: This review intends to comprehensively summarize the current studies on genetic variants associated with POP. Methods: We performed a comprehensive review to summarize the genetic findings from genome-linkage studies, genome-wide association studies, candidate association studies, and gene expression analyses. Results: We summarized genetic variants associated with connective tissue homeostasis, hormone metabolism, and oxidative stress, which were potentially related to the pathophysiology of POP. We also reviewed the limited polygenic risk score (PRS) studies generated for each individual's genetic risk stratification and its integration into clinical risk factors for disease prediction. Conclusions: This pooled analysis provides moderate epidemiological credibility for associations of these genetic variants with POP to bridge the gap between genetic research and clinical medicine towards understanding the genetic etiology of POP. It also highlights the potential of PRS as a risk prediction model.

4D DIA-PRM proteomic study identifying modulated pathways and biomarkers associated with pelvic organ prolapse

Pelvic organ prolapse (POP) is a highly disabling condition that negatively affects the quality of life of millions of women worldwide. However, the underlying mechanisms associated with the development and progression of the disease remain poorly understood. Here, an untargeted four-dimensional data-independent acquisition (4D DIA)-based proteomics approach was applied to vaginal wall tissue samples from POP (n = 19) and control (n = 8) patients to identify potential diagnostic biomarker(s) for POP and examine the molecular mechanisms underlying the disease. Of the 5713 tissue proteins that were detected, 1957 proteins were significantly changed in POP patients. Further bioinformatics analysis revealed that multiple biological processes including protein digestion & absorption, retrograde endocannabinoid signaling, tyrosine metabolism, and nucleotide metabolism were significantly enriched and associated with the pathogenesis of POP. Interestingly, 16 of these differentially expressed proteins associated with four pathways were also identified by targeted parallel reaction monitoring (PRM) proteomics analysis on the same 27 tissue samples. Changes in 94 % (15/16) of these proteins were consistent with the 4D DIA data. Furthermore, most proteins displayed good diagnostic accuracy with high area under the curve (AUC) values (AUC＞0.8). Specifically, five proteins including ELN, COL6A2, ENTPD1, AOC3, and COX7A2 distinguished between POP and control patients with very high accuracy (AUC ≥ 0.95) in both 4D DIA and PRM analyses, and may therefore be potential diagnostic biomarkers for POP. In summary, the present study not only provided several potential biomarker(s) for effective POP diagnosis, but extended our knowledge of the key regulatory pathways associated with the disease.

Mechanics of Uterosacral Ligaments: Current Knowledge, Existing Gaps, and Future Directions

The uterosacral ligaments (USLs) are important anatomical structures that support the uterus and apical vagina within the pelvis. As these structures are over-stretched, become weak, and exhibit laxity, pelvic floor disorders such as pelvic organ prolapse occur. Although several surgical procedures to treat pelvic floor disorders are directed toward the USLs, there is still a lot that is unknown about their function. This manuscript presents a review of the current knowledge on the mechanical properties of the USLs. The anatomy, microstructure, and clinical significance of the USLs are first reviewed. Then, the results of published experimental studies on the in vivo and ex vivo, uniaxial and biaxial tensile tests are compiled. Based on the existing findings, research gaps are identified and future research directions are discussed. The purpose of this exhaustive review is to help new researchers navigate scientific literature on the mechanical properties of the USLs. The use of these structures remains very popular in reconstructive surgeries that restore and augment the support of pelvic organs, especially as synthetic surgical mesh implants continue to be highly controversial.

Expressions of homeobox, collagen and estrogen genes in women with uterine prolapse

OBJECTIVE

Genetic contribution is thought to be involved in the pathophysiology of pelvic organ prolapse (POP). We aimed to study the gene expression profiles of the genes HomeoboxA11 (HOXA11), HomeoboxA13 (HOXA13), Collagen Type I (COL1A), Collagen Type III (COL3A), estrogen receptor genes (ESR1 and ESR2) of round (RL) and uterosacral ligaments (USL) in postmenopausal women with uterine prolapse.

STUDY DESIGN

Gene expressions of 32 postmenopausal women with prolapse were analysed according to gene expressions of 8 postmenopausal women without prolapse. Quantitative real-time PCR (qRT-PCR) method was used for the detection of expression levels of the genes. Student's t-Test and Mann-Whitney U test were used for statistical analysis.

RESULTS

In the USL specimens of all women with uterine prolapse HOXA13 and ESR1 gene expressions were decreased compared to controls (0.5 fold, p = 0.04 and 0.82 fold, p = 0.04, respectively). In the RL specimens, ESR2 gene expression was decreased 0.7 fold in women with prolapse when compared to controls (p = 0.04). In the USL specimens of women with advanced stages of prolapse (stage ≥3), HOXA13 and COL3A gene expressions were decreased compared to controls (0.44 fold, p = 0.043 and 0.39 fold, p = 0.045, respectively). In the RL specimens, ESR2 gene expression was decreased 0.65 fold in women with prolapse when compared to controls (p = 0.052).

CONCLUSION

The significant decrease in the expression of the genes HOXA13, COL3A in the USL and ESR2 in the RL especially in advanced stages of prolapse, implicate that these gene expressions may play a role in the development of uterine prolapse.

Genome‑wide DNA methylation analysis of uterosacral ligaments in women with pelvic organ prolapse

Pelvic organ prolapse (POP) is an increasingly serious health problem that impairs quality of life and is caused by multiple additive genetic and environmental factors. As the uterosacral ligaments (ULs) provide primary support for the pelvic organs, it was hypothesized that disruption of these ligaments (as a result of aberrant methylation) may lead to a loss of support and eventually contribute to POP. In the present study, whether there are any aberrant methylations in the ULs of patients with POP compared to those of controls was investigated. Genomic DNA was isolated from the ULs of five women with POP and four women without POP, as controls, undergoing hysterectomy for benign conditions. An Illumina Infinium Methylation EPICBeadChips Infinium Human Methylation 850 K bead array was used to investigate the total methylation in the ULs. There were 3,723 differentially methylated CpG sites (Δβ<0.14; P<0.05), including 3,576 hypermethylation and 147 hypomethylation sites in the ULs of patients with POP compared with the normal controls. There were more hypermethylated CpG sites, but a high ratio of hypomethylation between CpG islands and the N-shelf; in the gene structure, there was more hypermethylation than hypomethylation in TSS1500 and the 5′ untranslated region. Gene ontology analysis demonstrated that these differentially methylated genes were associated with ‘cell morphogenesis’, ‘extracellular matrix’, ‘cell junction’, ‘protein binding’ and ‘guanosine triphosphatase activity’. Several significant pathways were identified, including ‘focal adhesion’ and ‘extracellular matrix-receptor interaction pathway’. This study provides evidence that there are differences in genome-wide DNA methylation between ULs in menopausal women with and without POP, and that epigenetic mechanisms may partly contribute to POP pathogenesis.

Transcriptional Regulation of Connective Tissue Metabolism Genes in Women With Pelvic Organ Prolapse

OBJECTIVE

The aim of this study was to compare differences in expressions and relationships between key genes involved in extracellular matrix metabolism and tissue cellularity in women with and without pelvic organ prolapse (POP).

METHODS

A total of 80 biopsies (anterior cuff, posterior cuff, and/or leading edge) were obtained from 30 women: n = 10 premenopausal without POP (controls), n = 10 premenopausal with POP, and n = 10 postmenopausal with POP. Quantitative reverse-transcriptase polymerase chain reaction was used to assess gene expression of bone morphogenetic protein 1 (BMP1), collagen types I (COL1) and III (COL3), relaxin family peptide receptor 1 (RXFP1), matrix metallopeptidase 2, and TIMP metallopeptidase inhibitors 2 and 3. Hematoxylin and eosin staining was used to assess cellularity of the connective tissue layer. Kruskal-Wallis test, Mann-Whitney U test, Pearson correlation, or linear regression analyses were used, as appropriate.

RESULTS

Bone morphogenetic protein 1 expression was significantly up-regulated in patients with POP compared with controls. Bone morphogenetic protein 1 expression was correlated with COL1 expression in all groups but only correlated with TIMP metallopeptidase inhibitor 3 expression in controls. Similarly, COL3 expression was correlated with RXFP1 expression in women with POP but not in controls. The degree of dependence (slope of the regression line) between COL1 and COL3 expressions was significantly elevated in premenopausal women with POP compared with the other 2 groups. The slopes between COL1-COL3, COL3-matrix metallopeptidase 2, COL1-RXFP1, and COL3-RXFP1 expressions were significantly lower in postmenopausal women compared with premenopausal women with POP. No differences were found in overall tissue cellularity.

CONCLUSIONS

Bone morphogenetic protein 1 expression may play a significant role in the pathophysiology of POP. The finding that BMP1 expression was correlated with COL1 expression in all groups suggests a conserved association between BMP1 and collagen synthesis in the vaginal wall. The elevated slope between COL1 and COL3 expressions may be associated with early (premenopausal) development of POP. The expression of RXFP1 in postmenopausal women and its altered intergene regulation suggests a role for RXFP1 in connective tissue metabolism outside pregnancy.

Underexpression of HOXA11 Is Associated with Treatment Resistance and Poor Prognosis in Glioblastoma

Purpose

Homeobox (HOX) genes are essential developmental regulators that should normally be in the silenced state in an adult brain. The aberrant expression of HOX genes has been associated with the prognosis of many cancer types, including glioblastoma (GBM). This study examined the identity and role of HOX genes affecting GBM prognosis and treatment resistance.

Materials and Methods

The full series of HOX genes of five pairs of initial and recurrent human GBM samples were screened by microarray analysis to determine the most plausible candidate responsible for GBM prognosis. Another 20 newly diagnosed GBM samples were used for prognostic validation. In vitro experiments were performed to confirm the role of HOX in treatment resistance. Mediators involved in HOX gene regulation were searched using differentially expressed gene analysis, gene set enrichment tests, and network analysis.

Results

The underexpression of HOXA11 was identified as a consistent signature for a poor prognosis among the HOX genes. The overall survival of the GBM patients indicated a significantly favorable prognosis in patients with high HOXA11 expression (31±15.3 months) compared to the prognoses in thosewith low HOXA11 expression (18±7.3 months, p=0.03). When HOXA11 was suppressed in the GBM cell lines, the anticancer effect of radiotherapy and/or temozolomide declined. In addition, five candidate mediators (TGFBR2, CRIM1, TXNIP, DPYSL2, and CRMP1) that may confer an oncologic effect after HOXA11 suppression were identified.

Conclusion

The treatment resistance induced by the underexpression of HOXA11 can contribute to a poor prognosis in GBM. Further investigation will be needed to confirm the value of HOXA11 as a potential target for overcoming the treatment resistance by developing chemo- or radiosensitizers.

Downregulation of B7-H4 in the MHCC97-H hepatocellular carcinoma cell line by arsenic trioxide

Arsenic trioxide (As2O3; ATO), a compound which is characterized by its ability to function as a potent anticancer agent, has been investigated in a variety of carcinomas. B7‑H4, a transmembrane protein, may inhibit the function of the T cell effector, and therefore, may be useful in investigating different types of tumor therapies. However, few studies have been published previously associated with the roles of ATO and B7‑H4 in human hepatocellular carcinoma (HCC). The aim of the present study was to investigate the anti‑invasive role of ATO in HCC, to determine the effect of ATO treatment on the expression of B7‑H4 and to further assess the possible underlying mechanisms. Following treatment of the cells with 2, 4 and 8 µM ATO for 48 h, cell counting kit‑8 (CCK‑8), Transwell and western blot assays were used to determine the extent of human MHCC97‑H HCC cell proliferation, apoptosis, invasion and B7‑H4 expression, respectively. The results revealed that 1 µM ATO markedly decreased cellular proliferation, and ATO administered at concentrations of 0.1, 0.2 and 0.5 µM markedly inhibited the migration and invasion of the human MHCC97‑H HCC cell line. The expression of B7‑H4 in the treatment groups was markedly reduced. Signal transduction mediated via the Janus kinase 2/signal transducers and activators of transcription 3 pathway was inhibited upon treatment with 0.1, 0.2 and 0.5 µM ATO. Additionally, the protein expression levels of matrix metalloproteinase 2 and vascular endothelial growth factor were markedly reduced in HCC cells upon treatment with ATO. In conclusion, ATO may reduce the protein expression levels of B7‑H4 in MHCC97‑H HCC cells, and further affected HCC tumorigenesis and progression. ATO may be a putative agent for the development of therapeutic strategies against human liver cancer.

Association of matrix metalloproteinase-10 polymorphisms with susceptibility to pelvic organ prolapse

AIM

The aim of this study was to explore the correlation between genetic mutations in matrix metalloproteinase-10 (MMP-10) and susceptibility to pelvic organ prolapse (POP).

MATERIAL AND METHODS

From September 2011 to December 2013, 263 subjects were recruited, including 91 patients with POP (case group) and 172 non-POP patients (control group). Total MMP-10 concentrations in serum were measured by enzyme-linked immunosorbent assay. The genotyping of MMP-10 was achieved by quantitative real-time polymerase chain reaction. All data were analyzed with SPSS 18.0.

RESULTS

We found that parity, menopause, history of total hysterectomy, and family history of POP were all significantly higher in the POP group than in the control group (P = 0.017, P = 0.046, P = 0.0029 and P < 0.001, respectively). Serum MMP-10 levels were obviously higher in the POP group than in the control group (P < 0.05). In addition, there was a statistically significant difference between the two groups in the distribution frequency of the MMP-10 (rs17435959G/C) genotype (P < 0.05). However, the distribution frequency of the MMP-10 (rs17293607C/T) genotype between the two groups showed no significant differences (P > 0.05). Furthermore, the patients with parity > 2 and postmenopausal women had elevated serum MMP-10 levels, and the patients with parity > 2 and postmenopausal women who carried the G/C + C/C genotype in the MMP-10 gene had an increased risk of POP.

CONCLUSION

We support the view that the rs17435959 polymorphism of the MMP-10 gene may be associated with an increased risk of POP.

The long non-coding RNA HOTTIP enhances pancreatic cancer cell proliferation, survival and migration

HOTTIP is a long non-coding RNA (lncRNA) transcribed from the 5' tip of the HOXA locus and is associated with the polycomb repressor complex 2 (PRC2) and WD repeat containing protein 5 (WDR5)/mixed lineage leukemia 1 (MLL1) chromatin modifying complexes. HOTTIP is expressed in pancreatic cancer cell lines and knockdown of HOTTIP by RNA interference (siHOTTIP) in Panc1 pancreatic cancer cells decreased proliferation, induced apoptosis and decreased migration. In Panc1 cells transfected with siHOTTIP, there was a decrease in expression of 757 genes and increased expression of 514 genes, and a limited gene analysis indicated that HOTTIP regulation of genes is complex. For example, Aurora kinase A, an important regulator of cell growth, is coregulated by MLL and not WDR5 and, in contrast to previous studies in liver cancer cells, HOTTIP does not regulate HOXA13 but plays a role in regulation of several other HOX genes including HOXA10, HOXB2, HOXA11, HOXA9 and HOXA1. Although HOTTIP and the HOX-associated lncRNA HOTAIR have similar pro-oncogenic functions, they regulate strikingly different sets of genes in Panc1 cells and in pancreatic tumors.