Comparative analysis of AKT and the related biomarkers in uterine leiomyomas with MED12, HMGA2, and FH mutations

The use of Clinicopathological, immunohistochemistry and molecular detection in the diagnosis of fumarate hydratase-deficient uterine leiomyomas

BACKGROUND

Fumarate hydratase-deficient uterine leiomyomas (FH-dUL) are rare, accounting for only 0.4-1.6% of uterine leiomyomas. FH germline mutation gene is associated with hereditary leiomyomatosis and renal cell carcinoma syndrome (HLRCC).

METHODS

In this study, we aim to investigate Clinicopathological features and FH mutation in FH-dUL. We performed a retrospective analysis of 300 cases of uterine leiomyoma, diagnosed from January 2017 to December 2021, within the archives of the Department of Pathology at Peking University People's Hospital. In our review of the immunohistochemical(IHC) staining was performed on 300 uSMTs to detect FH deficiency.

RESULTS

We identified 21cases (21/300,7%) of FH-dUL. Nineteen cases (6.33%) displayed negative FH. Twenty-one cases (7%) displayed 2SC diffuse plasma and nuclear staining. The most common FH-d morphological features included staghorn vasculature ( 100%,21/21), alveolar-pattern oedema (71.43%, 15/21), scattered bizarre nuclei (23.81%, 5/21), eosinophilic cytoplasmic (rhabdoid) inclusions (47.62%, 10/21), significant eosinophilic nucleolus with peri-nucleolus hollowing (23.81%, 5/21), ovoid nuclei sometimes arranged in chains (9.52%, 2/21). DNA sequencing for the 21 cases was performed using Next Generation Sequencing (NGS). 6 cases were detected significant variations for the FH gene, 11 cases were detected FH gene mutation forvariants of uncertain significance (VUS), and 2 cases were detected a TP53 gene mutation. No related mutations were detected in the other two cases.

CONCLUSIONS

FH-dUL is rare. The combination of predictive Clinicopathological evaluation,FH and 2SC IHC test, and molecular test were helpful for the screening of FH-dUL from uSMTs,or even the screening of HLRCC.

Novel Approaches to Possible Targeted Therapies and Prophylaxis of Uterine Fibroids

Uterine leiomyomas are the most common benign tumors in women of childbearing age. They may lead to problems of conception or complications during the gestational period. The methods of treatment include surgical (myomectomy and hysterectomy, embolization of arteries) and therapeutic treatment (ulipristal acetate, leuprolide acetate, cetrorelix, goserelin, mifepristone). Both approaches are efficient but incompatible with pregnancy planning. Therefore, there is a call for medical practice to develop therapeutical means of preventing leiomyoma onset in patients planning on becoming pregnant. Based on the analysis of GWAS data on the search for mononucleotide polymorphisms associated with the risk of leiomyoma, in meta-transcriptomic and meta-methylomic studies, target proteins have been proposed. Prospective therapeutic treatments of leiomyoma may be based on chemical compounds, humanized recombinant antibodies, vaccines based on markers of the uterine leiomyoma cells that are absent in the adult organism, or DNA and RNA preparations. Three different nosological forms of the disease associated with driver mutations in the MED12, HMGA2, and FH genes should be considered when developing or prescribing drugs. For example, synthetic inhibitors and vaccines based on matrix metalloproteinases MMP11 and MMP16 are expected to be effective only for the prevention of the occurrence of MED12-dependent nodules.

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.

The role of insulin-like growth factor 2 mRNA binding proteins in female reproductive pathophysiology

Insulin-like growth factor 2 (IGF2) mRNA binding proteins (IMPs) family belongs to a highly conserved family of RNA-binding proteins (RBPs) and is responsible for regulating RNA processing including localization, translation and stability. Mammalian IMPs (IMP1-3) take part in development, metabolism and tumorigenesis, where they are believed to play a major role in cell growth, metabolism, migration and invasion. IMPs have been identified that are expressed in ovary, placenta and embryo. The up-to-date evidence suggest that IMPs are involved in folliculogenesis, oocyte maturation, embryogenesis, implantation, and placentation. The dysregulation of IMPs not only contributes to carcinogenesis but also disturbs the female reproduction, and may participate in the pathogenesis of reproductive diseases and obstetric syndromes, such as polycystic ovary syndrome (PCOS), pre-eclampsia (PE), gestational diabetes mellitus (GDM) and gynecological tumors. In this review, we summarize the role of IMPs in female reproductive pathophysiology, and hope to provide new insights into the identification of potential therapeutic targets.

HMGA2 Is a Useful Marker of Vulvovaginal Aggressive Angiomyxoma But May Be Positive in Other Mesenchymal Lesions at This Site

Aggressive angiomyxoma (AA) is a rare mesenchymal neoplasm occurring almost exclusively in the vulvovaginal region and which has a wide differential diagnosis. It has previously been suggested that the nuclear transcription factor HMGA2 is a useful marker of AA, although the number of studies is limited. We investigated HMGA2 immunoreactivity in a large series (n=284) of vulvovaginal mesenchymal lesions. HMGA2 nuclear staining was classified as diffuse (≥50%), focal (<50%), or negative. Of 38 cases of AA, 26 (68%) were positive; 77% (n=20) of these exhibited diffuse staining. Of the 41 smooth muscle tumors, 18 (44%) were positive with 16 (89%) exhibiting diffuse staining. 80 fibroepithelial stromal polyps were included and 15 (19%) were positive (8 diffuse; 7 focal). Most of the fibroepithelial stromal polyps that exhibited diffuse HMGA2 immunoreactivity were large and edematous. Occasional cases of a variety of other lesions were positive, including 1 of 30 superficial myofibroblastomas and 1 of 16 angiomyofibroblastomas. Cellular angiofibromas (n=12) and superficial angiomyxomas (n=6) were always negative. Our results confirm that HMGA2 is a useful marker of AA but a significant minority of cases are negative. The marker also lacks specificity, since a high percentage of smooth muscle tumors are positive, although these typically do not bear a close morphologic resemblance to AA. A novel observation in our study is positive staining of some fibroepithelial stromal polyps, particularly when large and edematous; these are particularly likely to be confused morphologically with AA and positive staining with HMGA2 represents a significant diagnostic pitfall.

Wnt/β-catenin signaling pathway in uterine leiomyoma: role in tumor biology and targeting opportunities

Uterine leiomyoma is the most common tumor of the female reproductive system and originates from a single transformed myometrial smooth muscle cell. Despite the immense medical, psychosocial, and financial impact, the exact underlying mechanisms of leiomyoma pathobiology are poorly understood. Alterations of signaling pathways are thought to be instrumental in leiomyoma biology. Wnt/β-catenin pathway appears to be involved in several aspects of the genesis of leiomyomas. For example, Wnt5b is overexpressed in leiomyoma, and the Wnt/β-catenin pathway appears to mediate the role of MED12 mutations, the most common mutations in leiomyoma, in tumorigenesis. Moreover, Wnt/β-catenin pathway plays a paracrine role where estrogen/progesterone treatment of mature myometrial or leiomyoma cells leads to increased expression of Wnt11 and Wnt16, which induces proliferation of leiomyoma stem cells and tumor growth. Constitutive activation of β-catenin leads to myometrial hyperplasia and leiomyoma-like lesions in animal models. Wnt/β-catenin signaling is also closely involved in mechanotransduction and extracellular matrix regulation and relevant alterations in leiomyoma, and crosstalk is noted between Wnt/β-catenin signaling and other pathways known to regulate leiomyoma development and growth such as estrogen, progesterone, TGFβ, PI3K/Akt/mTOR, Ras/Raf/MEK/ERK, IGF, Hippo, and Notch signaling. Finally, evidence suggests that inhibition of the canonical Wnt pathway using β-catenin inhibitors inhibits leiomyoma cell proliferation. Understanding the molecular mechanisms of leiomyoma development is essential for effective treatment. The specific Wnt/β-catenin pathway molecules discussed in this review constitute compelling candidates for therapeutic targeting.

The protective role of miR-132 targeting HMGA2 through the PI3K/AKT pathway in mice with Alzheimer's disease

OBJECTIVE

To explore the role and of miR-132, HMGA2 and PI3K/AKT pathway in mice with Alzheimer's disease (AD).

METHODS

The mice were divided into 7 groups: the normal group, the model group (AD model mice), the NC group (AD mice injected with negative control (NC) vector), the miR-132 mimic group (AD mice injected with miR-132 mimics), the miR-132 inhibitor group (AD mice injected with miR-132 inhibitor), the si-HMGA2 group (AD mice injected with HMGA2 silencing vector), and the miR-132 inhibitor + si-HMGA2 group (model mice treated with miR-132 inhibitor and si-HMGA2). Y-maze experiment and related molecular biology experiments were performed.

RESULTS

The double-luciferase reporter assay verified that miR-132 could target and inhibit the expression of HMGA2A. Compared with the NC group, model mice had decreased learning and memory ability, reduced miR-132, p-PI3K/PI3K, p-AKT/AKT, AQP4 expression as well as GFAP GSH-Px, SOD, ATP, and T-AOC levels, but increased expression of HMGA2 and the levels of TNF-α, IL-6, NO, IL-1β, MAO, and MDA (P<0.017). Up-regulation of miR-132 or silencing HMGA2 could partly reverse the changes, but inhibition of miR-132 would exaggerate the brain injury and these molecular changes (P<0.017). The combination uses of si-HMGA2 and miR-132 inhibitor could reverse the changes caused by miR-132 inhibitor (P<0.017).

CONCLUSION

miR-132 could downregulate the expression of HMGA2 and promote the expression of the PI3K/AKT pathway, so as to achieve a protective effect on brain in AD mice.

HMGA2 as a Critical Regulator in Cancer Development

The high mobility group protein 2 (HMGA2) regulates gene expression by binding to AT-rich regions of DNA. Akin to other DNA architectural proteins, HMGA2 is highly expressed in embryonic stem cells during embryogenesis, while its expression is more limited at later stages of development and in adulthood. Importantly, HMGA2 is re-expressed in nearly all human malignancies, where it promotes tumorigenesis by multiple mechanisms. HMGA2 increases cancer cell proliferation by promoting cell cycle entry and inhibition of apoptosis. In addition, HMGA2 influences different DNA repair mechanisms and promotes epithelial-to-mesenchymal transition by activating signaling via the MAPK/ERK, TGFβ/Smad, PI3K/AKT/mTOR, NFkB, and STAT3 pathways. Moreover, HMGA2 supports a cancer stem cell phenotype and renders cancer cells resistant to chemotherapeutic agents. In this review, we discuss these oncogenic roles of HMGA2 in different types of cancers and propose that HMGA2 may be used for cancer diagnostic, prognostic, and therapeutic purposes.

Activation of protein kinase B by WNT4 as a regulator of uterine leiomyoma stem cell function

OBJECTIVE

To investigate the functional interaction between the Wnt/β-catenin and protein kinase B (Akt) pathways in leiomyoma stem cells (LSC).

DESIGN

Laboratory study.

SETTING

Research laboratory.

PATIENT(S)

Premenopausal women (n = 36; age range: 28 to 49 years) undergoing hysterectomy or myomectomy for leiomyoma.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Gene expression, protein phosphorylation, and cell proliferation.

RESULT(S)

Cells from human leiomyoma tissues were sorted by fluorescence-activated cell sorting (FACS) into three populations: LSC, intermediate cells (LIC), and differentiated cells (LDC) with the function of the Wnt/β-catenin and Akt signaling pathways in leiomyoma cells evaluated using real-time quantitative polymerase chain reaction and immunoblot analyses. The Wnt/β-catenin signaling pathway components were differentially expressed in each leiomyoma cell population. WNT4 was distinctly overexpressed in LIC, and its receptor FZD6 was primarily expressed in LSC. WNT4 stimulated Akt phosphorylation, activated β-catenin, and increased primary leiomyoma cell proliferation. These stimulatory effects were abolished by cotreatment with the Akt inhibitor, MK-2206. WNT4 up-regulated the expression of pro-proliferative genes, c-Myc and cyclin D1, specifically in LSC; this was also abrogated by Akt inhibition.

CONCLUSION(S)

Our data suggest that WNT4 regulates LSC proliferation via Akt-dependent β-catenin activation, representing a key step toward a better understanding of LSC regulation and potentially novel therapeutic targets.

HMGA2-mediated tumorigenesis through angiogenesis in leiomyoma

OBJECTIVE

To study the role of HMGA2 in promoting angiogenesis in uterine leiomyoma (LM).

DESIGN

This study involved evaluation of vessel density and angiogenic factors in leiomyomas with HMGA2 overexpression; examining angiogenic factor expression and AKT signaling in myometrial (MM) and leiomyoma cells by introducing HMGA2 overexpression in vitro; and exploring vessel formation induced by HMGA2 overexpression both in vitro and in vivo.

SETTING

University research laboratory.

PATIENTS

None.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The main outcome measures include vessel density in leiomyomas with HMGA2 (HMGA2-LM) or MED12 (MED12-LM) alteration; angiogenic factor expression in primary leiomyoma and in vitro cell line model; and vessel formation in leiomyoma cells with HMGA2 overexpression in vitro and in vivo.

RESULTS

Angiogenic factors and receptors were significantly upregulated at mRNA and protein levels in HMGA2-LM. Specifically, HMGA2-LM exhibited increased expression of VEGFA, EGF, bFGF, TGFα, VEGFR1, and VEGFR2 compared to MED12-LM and myometrium. Overexpression of HMGA2 in MM and LM cell lines resulted in increased secretion of angiogenesis-associated factors. Secreted factors promoted human umbilical vein endothelial cell (HUVEC) migration, tube formation, and wound healing. HMGA2 overexpression upregulated IGF2BP2 and pAKT, and silencing the IGF2BP2 gene reduced pAKT levels and reduced HUVEC migration. Myometrial cells with stable HMGA2 overexpression exhibited increased colony formation and cell growth in vitro and formed xenografts with increased blood vessels.

CONCLUSIONS

HMGA2-LM have a high vasculature density, which likely contributes to tumor growth and disease burden of this leiomyoma subtype. HMGA2 plays an important role in angiogenesis and the involvement of IGF2BP2-mediated pAKT activity in angiogenesis, which provides a potential novel target for therapy for this subtype of LM.

An HMGA2-p62-ERα axis regulates uterine leiomyomas proliferation

Uterine leiomyomas (ULM) are a major public health issue contributing to high morbidity and poor pregnancy outcomes. However, its molecular pathogenesis is poorly understood. HMGA2-ULM is the second major subtype of human ULM and associates with large sizes, fast-growth, and high percentages of estrogen receptor α (ERα). As altered ERα expression plays a distinct role in ULM growth, here, we investigate a regulatory mechanism driving ULM growth via HMGA2 and ERα. We reveal a positive correlation of HMGA2 with ERα protein and demonstrate that HMGA2 promotes ULM cells proliferation via ERα. In addition, autophagy pathway and p62/SQSTM1 (a selective autophagy receptor) are found to participate in the regulation of HMGA2 and ERα. Moreover, HMGA2 suppresses the transcription of p62 by binding to its promoter, meanwhile, p62 interacts with ERα, and inhibition of p62 increases ERα expression and enhances cell viability in ULM, suggesting a novel mechanism of the HMGA2-p62-ERα axis in ULM proliferation. Notably, rapamycin, a familiar autophagy agonist, reduces ERα levels and the proliferation ability of ULM cells. This study demonstrates a causal role of the HMGA2-p62-ERα axis in preventing autophagy and increasing ERα expression in HMGA2-ULM. Therefore, blocking HMGA2-p62-ERα axis and targeting autophagy pathway establish a roadmap toward HMGA2-ULM medical treatment.

Reasons to Reconsider Risk Associated With Power Morcellation of Uterine Fibroids

Our insights into the molecular pathogenesis of uterine smooth muscle tumors have improved significantly. Accordingly, in the present review, we advocate a more refined risk assessment for patients considering surgical removal of fibroids or hysterectomy, respectively, requiring morcellation. For this procedure, the risk estimates given for the iatrogenic spread of a previously unexpected malignancy considerably vary among different studies. Nearly all previous studies conducted retrospectively refer to the risk of a patient having an unexpected malignancy at the time of surgery. We feel that, more appropriately, risk should refer to the number of tumors because, as a rule, every single nodule arises independently and, thus, carries an independent risk of being malignant or not. Furthermore, whether so-called parasitic fibroids carry an underestimated risk of stepwise malignant transformation is discussed.

Systematic Nucleotide Exchange Analysis of ESTs From the Human Cancer Genome Project Report: Origins of 347 Unknown ESTs Indicate Putative Transcription of Non-Coding Genomic Regions

Expressed sequence tags (ESTs) provide an imprint of cellular RNA diversity irrespectively of sequence homology with template genomes. NCBI databases include many unknown RNAs from various normal and cancer cells. These are usually ignored assuming sequencing artefacts or contamination due to their lack of sequence homology with template DNA. Here, we report genomic origins of 347 ESTs previously assumed artefacts/unknown, from the FAPESP/LICR Human Cancer Genome Project. EST template detection uses systematic nucleotide exchange analyses called swinger transformations. Systematic nucleotide exchanges replace systematically particular nucleotides with different nucleotides. Among 347 unknown ESTs, 51 ESTs match mitogenome transcription, 17 and 2 ESTs are from nuclear chromosome non-coding regions, and uncharacterized nuclear genes. Identified ESTs mapped on 205 protein-coding genes, 10 genes had swinger RNAs in several biosamples. Whole cell transcriptome searches for 17 ESTs mapping on non-coding regions confirmed their transcription. The 10 swinger-transcribed genes identified more than once associate with cancer induction and progression, suggesting swinger transformation occurs mainly in highly transcribed genes. Swinger transformation is a unique method to identify noncanonical RNAs obtained from NGS, which identifies putative ncRNA transcribed regions. Results suggest that swinger transcription occurs in highly active genes in normal and genetically unstable cancer cells.

Pathogenomics of Uterine Fibroids Development

We review recent studies dealing with the molecular genetics and basic results of omics analysis of uterine leiomyoma (LM)-a common benign muscle tumor of the uterus. Whole genome studies of LM resulted in the discovery of many new gene nets and biological pathways, including its origin, transcriptomic, and epigenetic profiles, as well as the impact of the inter-cell matrix in LM growth and involvement of microRNA in its regulation. New data on somatic cell mutations ultimately involved in the origin, distribution and growth of LM are reviewed. Putative identification of LM progenitor SC (stem cells) giving rise to maternal fibroid nodes and junctional zones provide a new clue for hypotheses on the pathogenomics of LM. The reviewed data are consistent with at least two different but probably intimately interacted molecular mechanisms of LM. One of them (the genetic hypothesis) is focused primarily on the MED12 gene mutations and suggests its onset in the side population of embryonic myoblasts of the female reproductive system, which later gave rise to multiple small and medium fibroids. The single and usually large-size fibroids are induced by predominantly epigenetic disorders in LM SC, provoked by enhanced expression of the HMGA2 gene caused by its hypomethylation and epigenetic deregulation enhanced by hypoxia, muscle tension, or chromosome instability/aberrations. The pathogenomics of both genetic and epigenetic programs of LM with many peculiarities at the beginning later became rather similar and partly overlapped due to the proximity of their gene nets and epigenetic landscape. Pathogenomic studies of LM open ways for elaboration of novel strategies of prevention and treatment of this common disease.

Clinico-pathological features of gynecological myopericytoma: a challenging diagnosis in an exceptional location

Myopericytomas (MPC) are rare mesenchymal tumors, originating from the perivascular myoid cells. They predominantly occur in the skin and superficial soft tissues of the extremities, while visceral involvement is rare. Histological features and clinical course are usually benign. To the best of our knowledge, MPC is still an uncharacterized tumor entity of the female internal genital tract. We describe three MPC cases involving the female internal genital tract: (1) a uterine wall MPC arising in a 49-year-old woman with progressive pelvic/abdominal pain; (2) a cervix MPC of a 49-year-old woman who presented with metrorrhagia, and (3) a MPC presenting as a simple ovarian cyst in a 26-year-old woman with pain located in the left iliac fossa. All patients were surgically treated, and recurrence occurred in two cases. The histological and immunohistochemical findings, supporting the diagnosis of MPC, are presented; in particular, one case showed characteristics pointing towards an uncertain biological behavior/low-grade malignancy. A literature search was conducted to identify previous reports of gynecological MPC and for possible alternative diagnoses. Leiomyoma, epithelioid leiomyoma, angioleiomyoma, perivascular epithelioid cell tumor, solitary fibrous tumor, and low-grade endometrial stromal sarcoma should be considered in the differential diagnosis. Awareness of possible occurrence of this rare neoplasm in the female genital tract is important to reach a correct diagnosis in the spectrum of mesenchymal tumors. Considering the risk of recurrence, we recommend careful evaluation of surgical margins and complete surgical removal whenever possible.

Hydropic leiomyoma: a distinct variant of leiomyoma closely related to HMGA2 overexpression

Hydropic leiomyoma (HLM) is a variant of uterine leiomyoma with characteristic features of zonal distributions of edema, increased vascularity, and tumor cells arranged in nodules or cords. Diagnostic difficulty and patient management are further complicated by a lack of studies and unknown cause of the disease. To study this tumor's nature, 24 HLM cases were selected for analysis of cytohistologic features, immunohistochemical profile (HMGA2, FH, CD34, pAKT, p16, ER, SMA, and Ki-67), and molecular alterations of HMGA2 by fluorescence in situ hybridization and MED12 mutations. HLM showed large tumor size (average 14.4 cm) and unique histology, characterized by edematous areas of tumor cells with mostly round-oval nuclei, arranged in cords and/or with perinodular growth around vessels, and increased thick-walled vessels (average 17 vessels/10× medium-power field). Immunohistochemistry revealed that 76% (18/24) of HLMs had HMGA2 overexpression, 32% (6/19) of which harbored HMGA2 rearrangement detected by fluorescence in situ hybridization. Thick-walled vessels in HLM were composed of mostly HMGA2-positive tumor cells, and HLM with HMGA2 overexpression also showed CD34-positive tumor vessel-supporting pericytes. In contrast to usual-type leiomyoma with a high frequency of MED12 mutations, no MED12 mutations were found in any HLM. HLM showed increased pAKT activity, indicating a strong contribution of AKT pathway signaling in HLM promoting tumor growth. Our findings suggest that HLM is a distinct variant of uterine smooth muscle tumor likely driven by HMGA2 overexpression.