Hydatidiform Research Articles

The Efficacy of Multiwavelength Red and Near-Infrared Transdermal Photobiomodulation Light Therapy in Enhancing Female Fertility Outcomes and Improving Reproductive Health: A Prospective Case Series with 9-Month Follow-Up

Background/Objectives: Female infertility due to unexpected causes exhibits a great challenge for both clinicians and women who are trying to conceive. The present clinical case series study aimed to evaluate the efficacy of multiple wavelengths of red and near-infrared (NIR) laser photobiomodulation (PBM) for increasing the potential of fertility in women and improving reproductive health in unexplained infertility issues. The objectives were to assess the following: (1) any adverse effects; (2) the possibility of producing an effective PBM protocol; (3) and healthy live birth. The inclusion criteria were to related to females who failed to conceive naturally beyond two years, multiple miscarriages, molar pregnancy, non-viable embryos from in vitro fertilisation (IVF) cycles, and failure to complete successful implantation of viable pre-implantation genetic tested (PGT-A) embryos. Methods: Case series of three female subjects with unexplained age-related infertility issues, which included a failure to conceive naturally beyond two years, multiple miscarriages, molar pregnancy, non-viable embryos from IVF cycles, and failure to complete successful implantation of viable pre-implantation genetic tested (PGT-A) embryos. In each case, previous conditions were recorded and then compared with outcomes after the patient received a course of PBM treatments. In every case, fertility outcomes improved. Three cases resulted in a full-term pregnancy and the birth of a healthy baby. PBM treatments were given at weekly and/or at two-week intervals using IR and NIR wavelengths between 600 nm and 1000 nm in the lead up to natural conception, IVF oocyte retrieval, blastocyst/embryo implantation, and/or the production of viable embryos. Results: In every case, fertility outcomes improved. Improvements in reproductive health outcomes in each case give reason to suggest that PBM may help to improve unexplained age-related infertility. Conclusions: Our study demonstrated that multiwavelength of red and NIR PBM with either an LED or laser, or a combination, improved female fertility and reproductive health and contributed to healthy live births in females diagnosed with unexplained age-related infertility. Extensive studies with robust data are warranted to validate our PBM dosimetry and treatment protocols. Moreover, understanding the genetic and phenotype biomarkers is important to standardise a range of PBM light dosimetry.

Defects in meiosis I contribute to the genesis of androgenetic hydatidiform moles.

To identify novel genes responsible for recurrent hydatidiform moles (HMs), we performed exome sequencing on 75 unrelated patients who were negative for mutations in the known genes. We identified biallelic deleterious variants in 6 genes, FOXL2, MAJIN, KASH5, SYCP2, MEIOB, and HFM1, in patients with androgenetic HMs, including a familial case of 3 affected members. Five of these genes are essential for meiosis I, and their deficiencies lead to premature ovarian insufficiency. Advanced maternal age is the strongest risk factor for sporadic androgenetic HM, which affects 1 in every 600 pregnancies. We studied Hfm1-/- female mice and found that these mice lost all their oocytes before puberty but retained some at younger ages. Oocytes from Hfm1-/- mice initiated meiotic maturation and extruded the first polar bodies in culture; however, their meiotic spindles were often positioned parallel, instead of perpendicular, to the ooplasmic membrane at telophase I, and some oocytes extruded the entire spindle with all the chromosomes into the polar bodies at metaphase II, a mechanism we previously reported in Mei1-/- oocytes. The occurrence of a common mechanism in two mouse models argues in favor of its plausibility at the origin of androgenetic HM formation in humans.

The role of single-dose prophylactic methotrexate in the prevention of post-molar gestational trophoblastic neoplasia in patients with high-risk molar pregnancy

IntroductionProphylactic chemotherapy (PC) has been suggested to be effective in prevention of post molar gestational trophoblastic neoplasia (PGTN) in patients with high-risk molar pregnancies. The goal of this study is to assess the efficacy of single dose methotrexate as PC in terms of spontaneous remission, time to remission, and progression to PGTN.Materials and methodsPatients with molar pregnancy were recruited to the study and underwent cervical dilation and suction curettage. Patients who had pathologically proven complete hydatidiform mole were evaluated with abdominal ultrasonography to confirm complete evacuation and absence of remnants. These patients were allocated to two groups: group one received Methotrexate 50 mg/m2 via intramuscular injection, while group two did not. PGTN was defined according to the 2018 FIGO criteria. For patients with confirmed PGTN, the following variables were recorded: occurrence of metastasis, resistance to first-line chemotherapy and time to βHCG level normalization.ResultsEighty patients were enrolled to the study, of which 22 cases (27.5%) received PC. It was found that PC with MTX did not significantly influence spontaneous remission (18 (81.8%) Vs 37 (63.7%), p value: 0.12) or time to remission (57 ± 22.5 Vs 61.24 ± 21.78 days, p value: 0.46) in high-risk molar pregnancies. Moreover, among patients in PC group and control group, 4 cases (18.2%) and 21 patients (36.3%) progressed to PGNT, respectively (p value: 0.12). Although patients in PC group tended to be diagnosed in lower stages compared to patients in control group, this difference was insignificance (p value: 0.95). Among patients who developed to PGTN, PC did not reduce the frequency of metastatic disease, resistance to first-line chemotherapy, or the time interval to serum βHCG level normalization (all p values > 0.05).ConclusionThis study suggests that a single-dose MTX as PC may not be an effective therapeutic option for preventing PGTN in patients with high-risk molar pregnancy.

How long is hCG monitoring required after normalization following evacuation of a complete hydatidiform mole? A national, retrospective population study

How long is hCG monitoring required after normalization following evacuation of a complete hydatidiform mole? A national, retrospective population study

Trisomy 16 mimicking hydatidiform mole.

The authors present a case of 1st trimester miscarriage where an early, complete hydatidiform mole was clinically suspected. Histopathological and immunohistochemical analyses excluded a complete mole, but the histomorphological profile was in concordance with a partial hydatidiform mole. Genetic analysis excluded a partial mole based on biparental genome composition, where further genetic analyses detected trisomy of chromosome 16. Trisomy of chromosome 16 is a frequent cause of 1st trimester abortions and may lead to highly abnormal placental histomorphology mimicking a partial mole. Genetic analyses are crucial for proper differential diagnosis and for the determination of adequate follow-up and prognosis for further pregnancies.

Gestational Trophoblastic Tumours: Experience of the Oncology Department of the Moulay Ismail Military Hospital in Meknes (10 Cases)

Gestational trophoblastic tumors (GTTs) are the malignant forms of gestational trophoblastic diseases. They always follow a pregnancy, most often molar. The diagnosis of GTT is based on an abnormal course of HCG (chorionic gonadotropin hormone) and/or signs of ultrasound invasion and/or histological confirmation. We report a retrospective series of 10 cases of GTT collected at the Medical Oncology Department of the Moulay Ismail Military Hospital in Meknes over an 8-year period from January 2012 to January 2020. The analysis of our series led to the conclusion that: The average age of onsetis 42 years. 90% of our patients were pauciparic. The causal pregnancy was in 90% of the cases a molar pregnancy. The extension assessment was mainly based on the TAP CT identifying the lung as the main metastatic site in 40% of cases. 5 patients (50% of cases) underwent hysterectomy with post operative chemotherapy. 60% of our patients were classified as low risk according to the FIGO score and received methotrexate mono-chemotherapy. 4 patients were classified as high-risk and were treated with poly chemotherapy, the main protocol of which was EMA-CO. All our patients benefited from clinical and biological monitoring, before each chemotherapy session; then weekly and monthly after negativation, up to 12 months in case of good prognosis GTT, and up to 18 months in case of bad prognosis GTT. One case of MTX relapse (the case of IPTT) was reported and for which a 2nd line CMT with a favourable evolution was indicated. This study allowed us to analyze the cure rate, which was 100% for patients who were treated and had completed their monitoring.

Association of gestational trophoblastic disease with subsequent development of non-trophoblastic cancer.

To evaluate the association between gestational trophoblastic disease and the subsequent risk of developing non-trophoblastic cancer. We conducted a retrospective cohort study of 3084 women with gestational trophoblastic disease and 1 415 812 women with obstetric deliveries in Quebec, Canada, between 1989 and 2021. The main exposure was gestational trophoblastic disease, including hydatidiform moles, invasive moles, and gestational choriocarcinoma. The outcome was development of non-trophoblastic cancer during 33 years of follow-up. We measured the association of gestational trophoblastic disease with non-trophoblastic cancer using adjusted hazard ratios (HR) and 95% confidence intervals (CI), and tested whether associations were stronger for certain types of cancer or cancers with later onset. The incidence of non-trophoblastic cancer was greater for women with invasive moles (47.1/10 000 person-years) and gestational choriocarcinoma (59.3/10 000 person-years) than hydatidiform moles (18.4/10 000 person-years) and no gestational trophoblastic disease (22.4/10 000 person-years). Gestational choriocarcinoma (HR 2.33, 95% CI: 1.35-4.01; P = 0.002) and invasive moles (HR 1.97, 95% CI: 1.06-3.65; P = 0.033) were associated with an elevated risk of non-trophoblastic cancer compared with no gestational trophoblastic disease, while hydatidiform moles were not. Gestational choriocarcinoma and invasive moles were mainly associated with gynecologic cancer. However, risk of cancer was limited to the short-term period after pregnancy and became similar to no gestational trophoblastic disease by the end of follow-up. While invasive moles and gestational choriocarcinoma appear to be associated with the subsequent development of non-trophoblastic cancer, the absolute risk is small and limited to the short-term.

7617 Two Cases of Severe Beta-hCG-Mediated Hyperthyroidism with Gestational Trophoblastic Disease

Abstract Disclosure: A. Morvant: None. M. Mashayekhi: None. Introduction: Hyperthyroidism is most commonly caused by Graves’ disease and toxic nodules and affects 2.5% of the world’s population. Hyperthyroidism due to elevations in beta-hCG (b-hCG), which has thyroid-stimulating activity due to homology with TSH, is a rare process that requires high clinical suspicion. We present two cases of hyperthyroidism caused by severely elevated b-hCG due to gestational trophoblastic disease (GTD), with rapid resolution of hyperthyroidism after treatment of the underlying conditions. Clinical Cases Case 1: A 35-year-old at 28-weeks gestation presented with dyspnea, palpitations, and 6-pound weight loss over the prior month. Labs revealed b-hCG 5.2 million (0-5 mIU/mL), TSH <0.015 (0.35-3.6 mcU/mL), and free T4 2.42 (0.7-1.37 ng/dL). Imaging revealed extensive pulmonary lesions concerning for metastatic disease and a 2.4 cm ovarian mass. Due to worsening respiratory distress and the need to start chemotherapy urgently, she underwent Cesarean section to deliver the viable infant and take out the ovarian mass. Pathology confirmed choriocarcinoma. Methimazole was started post-operatively, and she started chemotherapy. Labs after cycle one of chemotherapy showed b-hCG 1.3 million, TSH <0.015, and free T4 1.46. The methimazole dose was decreased and ultimately stopped as free T4 levels decreased with subsequent chemotherapy cycles. After three cycles, labs showed b-hCG 4,652, TSH 1.55, and free T4 0.68. She was discharged without thyroid-targeting therapy. Case 2: A 33-year-old woman at 12-weeks gestation presented with nausea, vomiting, and 10-pound weight loss over 1 month. Labs showed TSH <0.015, free T4 2.39, and total T3 351 (58-160 ng/dL), which were thought to be due to hyperemesis gravidarum. Two months later she presented with vaginal bleeding and imaging showed an enlarged placenta with a moth-eaten appearance and theca lutein cysts concerning for partial molar pregnancy. Beta-hCG level was 3.3 million, TSH <0.015, free T4 1.76, and total T3 289. She underwent dilation and evacuation and pathology confirmed partial hydatidiform mole. Beta-hCG level decreased to 1.8 million and free T4 normalized after surgery, with b-hCG 3,300, normal TSH, and normal total T3 one month later. Conclusion: These cases highlight the importance of considering possible GTD when evaluating a patient with hyperthyroidism, particularly in women of childbearing age and cases of early pregnancy when the degree of hyperthyroidism seems out of proportion to that expected. Clinicians should consider checking a b-hCG level in consultation with an obstetrician when indicated. Treatment is aimed at the GTD and can yield rapid resolution of hyperthyroidism.

A-337 The Utility of Urinary Human Chorionic Gonadotropin Testing in the Emergency Department

Abstract Background Human chorionic gonadotropin (hCG) levels are measured in both urine and blood as an indication of suspected pregnancy, and assessment of progress of conception. It is also measured in the investigation of patients presenting with acute abdomen and suspected of ectopic or molar pregnancy. This study reviewed the utility of urine pregnancy test in a large university teaching hospital. Methods Results of all urinary hCG tests (using hCG Combo Pregnancy kit, MEDLINE, IL) performed as point of care in the emergency department during the year 2023 were obtained. Corresponding plasma hcG levels performed (Total β-HCG Alinity immunoassay, Abbott Diagnostics, IL) were also obtained. Analysis of hCG testing outcomes were assessed. Results A total of 2848 urinary hCG tests were performed during the study period. The majority 2113 (74.2%) of samples were negative for hCG whereas 835 samples (29.3) were positive. Among the positive hCG urine samples, 401 patients (48%) had plasma hCG requested and performed. Plasma hCG values ranged from < 2.4 (26.5) to 219,462.5 mIU/mL (median 16,872.35 mIU/mL). One plasma sample with corresponding positive urinary hCG result had plasma hCG level <2.4 mIU/mL which is below the detection limit of the assay suggesting a false positive urinary hCG result. Among the 13 patients with serial plasma hCG values, only one patient exhibited doubling (48 hours) hCG values when less than 13,000 mIU/mL. One patient had a declining serial hCG plasma values suggesting failing conception. The remaining patients with consecutive plasma hCG values cannot be assessed as either the time gap was excessive or hCG values were markedly elevated (> 30,000 mIU/mL). Conclusions Although the utility of urinary hCG testing in the emergency department appeared appropriate, unnecessary repeat analysis with appropriate plasma request represented 3.2%. An electronic test request duplicate notification may help resolve this unnecessary repeat.

Prevalence and management of ectopic and molar pregnancies in 17 countries in Africa and Latin America and the Caribbean: a secondary analysis of the WHO multi-country cross-sectional survey on abortion

IntroductionThere are limited global data on ectopic pregnancy (EP) and molar pregnancy (MP), making it important to understand their epidemiology and management across different regions. Our study aimed to describe...

Trophoblastic disease and choriocarcinoma

Gestational trophoblastic disease (GTD) is a group of diseases associated with pregnancies that demonstrate abnormal development of trophoblastic cells. GTD includes hydatidiform moles (HM) that may continue to further develop into gestational trophoblastic neoplasms (GTN), such as choriocarcinoma (CC). Gestational CC is a malignant mass development that may arise from HM, from other (normal) pregnancies or from other gestational events (such as ectopic pregnancies). The aim of this review is to outline current understating of the genetics and epigenetics of GTD and gestational CC and the link between the two diseases.

Ultrasonic detective: Solving the mystery of molar pregnancy

Ultrasonic detective: Solving the mystery of molar pregnancy

The causal relationship between hydatidiform mole and nutrients: A two-sample Mendelian randomization study

BackgroundHydatidiform mole (HM), a subset of gestational trophoblastic disease, is considered precancerous and exhibits geographical variation. The incidence of HM is linked to nutritional factors. This study aimed to investigate the causal relationship between nutrients and HM using a bidirectional two-sample Mendelian randomization (MR) approach. MethodsWe utilized publicly available genome-wide association study data to assess the causal associations between levels of specific vitamins (retinol, vitamins B12, B6, C, D, E, folate, and carotene) and minerals (iron, calcium, and magnesium) with HM. The MR analysis was conducted and reported following the STROBE-MR guidelines, employing MR Egger and inverse variance weighted (IVW) methods to estimate associations, with MR-PRESSO for pleiotropy testing. ResultsThe study revealed vitamin B6 as a significant protective factor against HM (MR-Egger OR: 0.094, 95% CI: 0.011-0.0778, P < 0.05; IVW OR: 0.365, 95% CI: 0.142-0.936, P < 0.05). Folate and magnesium showed suggestive associations with HM, whereas most other nutrients did not exhibit a causal relationship. MR-PRESSO analysis supported the absence of horizontal pleiotropy of vitamin B6. Besides, reverse MR analysis did not reveal a significant causal association between HM and serum nutrient levels, suggesting that differences of nutrients in HM patients may not be directly attributed to the mole. ConclusionThis MR study provides evidence that vitamin B6 may protect against HM, and suggests potential roles for folate and magnesium in HM development, while highlighting the need for further research to confirm these findings.

Comprehensive Proteomic Analysis Reveals Distinct Features and a Diagnostic Biomarker Panel for Early Pregnancy Loss in Histological Subtypes

Early pregnancy loss (EPL) is a common event in human reproduction and is classified into histological subtypes such as hydropic abortion (HA) and hydatidiform moles, including complete hydatidiform moles (CHMs) and partial hydatidiform moles (PHMs). However, accurate diagnosis and improved patient management remain challenging due to high rates of misdiagnosis and diverse prognostic risks. Therefore, diagnostic biomarkers for EPL are urgently needed. Our study aimed to identify biomarkers for EPL through comprehensive proteomic analysis. Ten CHMs, six PHMs, ten HAs, and 10 normal control products of conception were used to obtain a proteomic portrait. Parallel reaction monitoring-targeted proteomic and regression analyses were used to verify and select the diagnostic signatures. Finally, 14 proteins were selected and a panel of diagnostic classifiers (DLK1, SPTB/COL21A1, and SAR1A) was built to represent the CHM, PHM, and normal control groups (area under the receiver operating characteristic curve = 0.900, 0.804/0.885, and 0.991, respectively). This high diagnostic power was further validated in another independent cohort (n=148) by immunohistochemistry (n=120) and Western blot analyses (n=28). The protein SPTB was selected for further biological behavior experiments invitro. Our data suggest that SPTB maintains trophoblast cell proliferation, angiogenesis, cell motility, and the cytoskeleton network. This study provides a comprehensive proteomic portrait and identifies potential diagnostic biomarkers. These findings enhance our understanding of EPL pathogenesis and offer novel targets for diagnosis and therapeutic interventions.

Enhanced Extravillous Trophoblast Gene Expression at the Origin of the Pathology of Hydatidiform Moles and their Malignancies.

Enhanced Extravillous Trophoblast Gene Expression at the Origin of the Pathology of Hydatidiform Moles and their Malignancies.

Elucidation of the role of XBP1 in the progression of complete hydatidiform mole to invasive mole through RNA-seq

ObjectiveA complete hydatidiform mole (CHM) is a common disease and is known to develop post-molar gestational trophoblast neoplasia (GTN). However, the molecular mechanisms underlying the progression of CHM to post-molar GTN remain largely unknown. In this study, we investigated the molecular factors associated with the progression using RNA-seq. MethodsWe included 13 patients with CHM and performed RNA-seq using freshly frozen samples. We identified differentially expressed genes between patients who developed GTN (GTN group) and those who achieved spontaneous remission after uterine evacuation (SR group), and performed pathway analysis. Then, functional analyses were performed on choriocarcinoma (JAR and JEG-3) and CHM (Hmol1-3B and Hmol1-2C) cells. Moreover, we evaluated the in vivo tumorigenicity of XBP1-overexpressed Hmol1-3B cells. ResultsThe gene expression profiles were separated into two groups, and an upstream regulator analysis was performed using 281 differentially expressed genes. We focused on transcription factors and identified that 33 transcription factors were activated in the GTN group. Then, excluding those with low expression levels in clinical samples and cell lines, XBP1 was selected for further analysis. Additionally, XBP1 downregulation significantly decreased the migration and invasive abilities of choriocarcinoma cells, whereas XBP1 overexpression significantly increased the migration and invasive abilities of CHM cells. Furthermore, animal experiments showed that tumor weight and blood human chorionic gonadotropin (hCG) levels were significantly higher in the XBP1-overexpressing Hmol1-3B-bearing mice than those in the control mice. ConclusionRNA-seq identified XBP1 as a key factor in post-molar GTN, suggesting it contributes to the development of post-molar GTN.

Androgenetic/biparental mosaic/chimeric gestation: A case report

Introduction: Androgenetic/biparental mosaic/chimeric (ABMC) conceptions are a rare group of gestational trophoblastic disease (GTD) that arise as a result of mosaicism or chimerism and are characterized by hydropically enlarged and variably sized villi. Currently, there are very few reports describing ABMC conceptions; there are 13 total in the literature, and even more rare are those with a molar component. Case Report: A 27-year-old female patient at 6+4wga presented to the clinic with a complaint of new vaginal bleeding and was diagnosed with a pregnancy of unknown location. The patient re-presented to the clinic at 8+4wga by last menstrual period (LMP) for a follow-up ultrasound. A serum human chorionic gonadotropin (hCG) was ordered and returned at 424,008 mIU/mL. A transvaginal ultrasound demonstrated a heterogeneous “snowstorm” appearance throughout uterine cavity, with a concern for complete mole in the setting of a significantly elevated beta hCG. The patient underwent a suction dilation and curettage with ultrasound guidance. Pathology returned the following report: The specimen was sent to pathology and DNA ploidy returned as diploid; however, p57 demonstrated a discordant staining pattern characterized by expression in villous cytotrophoblast but the absence in villous stromal cells was characteristic of androgenetic/biparental mosaic/chimeric gestation. No fetal parts were identified in gross examination of the specimen. Conclusion: Androgenetic/biparental mosaic/chimeric (ABMC) conceptions are important to accurately diagnose because the molar form carries an increased risk for persistent gestational trophoblastic diseases. There are few case reports published regarding ABMC cases. We present this case to provide additional data to the field and emphasize the utility for p57 immunohistochemistry and genetic testing to be performed.

Normally Developing Pregnancy and Hydatidiform Mole: A Case Report

Introduction: Hydatidiform mole with a normally developing fetus is a rare case associated with an increased risk of bleeding, preterm birth, preeclampsia, congenital anomalies, and intrauterine fetal death.Case report: We report a case of a twin pregnancy with a hydatidiform mole and a normal fetus. The pregnancy was conceived via in vitro fertilization. The complete hydatidiform mole was diagnosed during the first screening. We extended the pregnancy until 38 weeks’ gestation. Thanks to the control of beta-human chorionic gonadotropin levels and dynamic ultrasound monitoring, the woman successfully gave birth.

Cesarean scar choriocarcinoma following a cesarean scar molar pregnancy: A case report

Gestational choriocarcinoma, a rare variant of gestational trophoblastic disease, typically arises from abnormal trophoblastic cell proliferation post-pregnancy, often associated with a hydatidiform mole. While most choriocarcinoma cases develop within the uterine cavity, an exceedingly rare manifestation occurs within a previous cesarean section scar. In our study, a 31-year-old woman with a history of hydatidiform mole presented with amenorrhea and spotting. Initial assessments revealed elevated beta-human chorionic gonadotropin (βhCG) levels and a heteroechoic mass at her prior cesarean section scar in sonographic examination. Histopathologic findings and the metastatic workup categorized the patient as FIGO stage I, indicating no metastasis. Due to the absence of metastasis, adjuvant chemotherapy was omitted. Total abdominal hysterectomy confirmed choriocarcinoma. Post-surgery, βhCG levels notably decreased, remaining negative during the two-year follow-up with no reported symptoms. Our findings suggest that surgical resection and meticulous βhCG monitoring may be a promising treatment strategy for non-metastatic choriocarcinoma.

Hypermethylated RASAL1’s promotive role in chemoresistance and tumorigenesis of choriocarcinoma was regulated by TET2 but not DNMTs

BackgroundPatients with choriocarcinoma (CC) accompanying chemoresistance conventionally present a poor prognosis. Whether ras protein activator like-1 (RASAL1) functions as a tumor promoter or suppressor depends on tumor types. However, the role of RASAL1 in process of chemoresistance of CC and underlying molecular mechanism remain elusive.MethodsThe expression pattern of RASAL1 in CC cells and tissues was measured using Western blotting, immunohistochemistry and qRT-PCR. Cell viability and proliferative ability were assessed by MTT assay, Tunnel assay and flow cytometric analysis. Additionally, the stemness was evaluated by the colony formation and tumor sphere formation. Methotrexate (MTX) was applied to exam the chemosensitivity of CC cells.ResultsThe expression of RASAL1 was reduced both at the protein and mRNA levels in CC tissues and cells compared to hydatidiform mole (HM) and invasive mole (IM). Loss of RASAL1 was attributed to its promoter hypermethylation and could be restored by 5-Aza. Knock-down of RASAL1 promoted the viability, proliferative potential, stemness and EMT phenotype of JEG-3 cells. However, induced overexpression of RASAL1 by 5-Aza significantly prohibited cell proliferation and stemness potential of the JAR cell. Additionally, the xenograft model indicated that knockdown of RASAL1 led to a remarkable increase of tumor volume and weight in comparison with its counterpart. Moreover, the stimulatory activity brought by decrease of RASAL1 could be deprived by β-catenin inhibitor XAV 939, yet the suppressive activity resulted from its promoter demethylation could be rescued by β-catenin activator BML-284, indicating that function of RASAL1 depends on β-catenin. Besides, the co-immunoprecipitation assay confirmed the physical binding between RASAL1 and β-catenin. Further investigations showed hypermethylated RASAL1 was regulated by TET2 but not DNMTs.ConclusionTaken together, the present data elucidated that reduced RASAL1 through its promoter hypermethylation regulated by TET2 promoted the tumorigenicity and chemoresistance of CC via modulating β-catenin both in vitro and in vivo.