Dual-specificity phosphatase 6 plays a critical role in the maintenance of a cancer stem-like cell phenotype in human endometrial cancer

KIFC1 depends on TRIM37-mediated ubiquitination of PLK4 to promote centrosome amplification in endometrial cancer

Endometrial cancer (EC), as one of the most common cancers, severely threatens female reproductive health. Our previous study has shown that Kinesin family member C1 (KIFC1) played crucial roles in the progression of EC. In addition, abnormal centrosome amplification, which was reported to be partially regulated by KIFC1, usually occurred in different cancers. However, whether KIFC1 promoted EC through centrosome amplification and the potential mechanism remain to be revealed. The present study demonstrated that overexpressed KIFC1, which exhibited a worse prognosis, had a positive correlation with an increased number of centrosomes in human EC samples. In addition, KIFC1 overexpression in EC cells prompted centrosome amplification, chromosomal instability, and cell cycle progression. Moreover, we demonstrated that KIFC1 inhibited E3 ubiquitin-protein ligase TRIM37 to maintain the stability of PLK4 by reducing its ubiquitination degradation, and finally promoting centrosome amplification and EC progression in vitro. Finally, the contributing role of KIFC1 and the inhibitory effect of TRIM37 on EC development and metastasis was verified in a nude mouse xenograft model. Our study elucidated that KIFC1 depends on TRIM37-mediated reduced ubiquitination degradation of PLK4 to promote centrosome amplification and EC progression, thus providing a potential prognostic marker and promising therapeutic target for EC in the future.

SMYD3 promotes endometrial cancer through epigenetic regulation of LIG4/XRCC4/XLF complex in non-homologous end joining repair

Endometrial cancer (EC) stands as one of the most prevalent malignancies affecting the female genital tract, witnessing a rapid surge in incidence globally. Despite the well-established association of histone methyltransferase SMYD3 with the development and progression of various cancers, its specific oncogenic role in endometrial cancer remains unexplored. In the present study, we report that the expression level of SMYD3 is significantly upregulated in EC samples and associated with EC progression. Through meticulous in vivo and in vitro experiments, we reveal that depletion of SMYD3 curtails cell proliferation, migration, and invasion capabilities, leading to compromised non-homologous end joining repair (NHEJ) and heightened sensitivity of EC cells to radiation. Furthermore, our pathway enrichment analysis underscores the pivotal involvement of the DNA damage repair pathway in regulating EC progression. Mechanistically, in response to DNA damage, SMYD3 is recruited to these sites in a PARP1-dependent manner, specifically methylating LIG4. This methylation sets off a sequential assembly of the LIG4/XRCC4/XLF complex, actively participating in the NHEJ pathway and thereby fostering EC progression. Notably, our findings highlight the promise of SMYD3 as a crucial player in NHEJ repair and its direct correlation with EC progression. Intriguingly, pharmacological intervention targeting SMYD3 with its specific inhibitor, BCI-121, emerges as a potent strategy, markedly suppressing the tumorigenicity of EC cells and significantly enhancing the efficacy of radiotherapy. Collectively, our comprehensive data position SMYD3 as a central factor in NHEJ repair and underscore its potential as a promising pharmacological target for endometrial cancer therapy, validated through both in vitro and in vivo systems.

Identification of stemness subtypes and features to improve endometrial cancer treatment using machine learning

Endometrial cancer is one of the most common malignant tumours in women, and cancer stem cells are known to play an important role in its growth, invasion, metastasis, and drug resistance. Immunotherapy for endometrial cancer is still under research. In this study, a total of 547 endometrial cancer cases were randomly divided into training set (351 cases) set and test set (196 cases). The stemness index of patients was calculated using the One-Class Logistic Regression (OCLR) machine learning algorithm to explore the clinicopathological differences between index levels. Stemness subtypes were determined according to the characteristics of cancer stemness and their clinicopathological characteristics, immune features, and therapeutic effects were described. Our study suggests that endometrial cancer is classified into two stemness subtypes. Stemness subtypes, which are associated with its clinical features, may be independent prognostic factors for endometrial cancer. The stemness subtypes differed significantly in immune activity, immune cell infiltration, and the immune microenvironment, including sensitivity to chemotherapeutic drugs and potential therapeutic compounds. Algorithms were utilised to construct a stemness subtype prediction model and predictor. These findings will provide guidance for the clinical diagnosis, treatment, and prognosis of endometrial cancer.

A simple and robust serum-free media for the proliferation of muscle cells

Cultivated meat production requires an efficient, robust and highly optimized serum-free cell culture media for the needed upscaling of muscle cell expansion. Existing formulations of serum-free media are complex, expensive and have not been optimized for muscle cells. Thus, we undertook this work to develop a simple and robust serum-free media for the proliferation of bovine satellite cells (SCs) through Design of Experiment (DOE) and Response Surface Methodology (RSM) using precise and high-throughput image-based cytometry. Proliferative attributes were investigated with transcriptomics and long-term performance was validated using multiple live assays. Here we formulated a media based on three highly optimized components; FGF2 (2 ng/mL), fetuin (600 µg/mL) and BSA (75 µg/mL) which together with an insulin-transferrin-selenium (1x) supplement, sustained the proliferation of bovine SCs, porcine SCs and murine C2C12 muscle cells. Remarkably, cells cultured in our media named Tri-basal 2.0+ performed better than cell cultured in 10% FBS, with respect to proliferation. Hence, the optimized Tri-basal 2.0+ enhanced serum-free cell attachment and long-term proliferation, providing an alternative solution to the use of FBS in the production of cultivated meat.

miR-101-5p suppresses trophoblast cell migration and invasion via modulating the DUSP6-ERK1/2 axis in preeclampsia

PURPOSE

Dysregulated behaviors of trophoblast cells leading to defective placentation are considered the main cause of preeclampsia (PE). Abnormal miRNA expression profiles have been observed in PE placental tissue, indicating the significant role of miRNAs in PE development. This study aimed to investigate the expression of miR-101-5p in PE placental tissue and its biological functions.

METHODS

The expression of miR-101-5p in placental tissue was detected by quantitative real-time PCR (qRT-PCR). The localization of miR-101-5p in term placental tissue and decidual tissue was determined by the fluorescence in situ hybridization (FISH)-immunofluorescence (IF) double labeling assay. The effect of miR-101-5p on the migration, invasion, proliferation, and apoptosis of the HTR8/SVneo trophoblast cells was investigated. Online databases combined with transcriptomics were used to identify potential target genes and related pathways of miR-101-5p. Finally, the interaction between miR-101-5p and the target gene was verified by qRT-PCT, WB, dual-luciferase reporter assay, and rescue experiments.

RESULTS

The study found that miR-101-5p was upregulated in PE placental tissue compared to normal controls and was mainly located in various trophoblast cell subtypes in placental and decidual tissues. Overexpression of miR-101-5p impaired the migration and invasion of HTR8/SVneo cells. DUSP6 was identified as a potential downstream target of miR-101-5p. The expression of miR-101-5p was negatively correlated with DUSP6 expression in HTR8/SVneo cells, and miR-101-5p directly bound to the 3' UTR region of DUSP6. DUSP6 upregulation rescued the migratory and invasive abilities of HTR8/SVneo cells in the presence of miR-101-5p overexpression. Additionally, miR-101-5p downregulated DUSP6, resulting in enhanced ERK1/2 phosphorylation.

CONCLUSION

This study revealed that miR-101-5p inhibits the migration and invasion of HTR8/SVneo cells by regulating the DUSP6-ERK1/2 axis, providing a new molecular mechanism for the pathogenesis of PE.

A distinct transcriptome characterizes neural crest-derived cells at the migratory wavefront during enteric nervous system development

Enteric nervous system development relies on intestinal colonization by enteric neural crest-derived cells (ENCDCs). This is driven by a population of highly migratory and proliferative ENCDCs at the wavefront, but the molecular characteristics of these cells are unknown. ENCDCs from the wavefront and the trailing region were isolated and subjected to RNA-seq. Wavefront-ENCDCs were transcriptionally distinct from trailing ENCDCs, and temporal modelling confirmed their relative immaturity. This population of ENCDCs exhibited altered expression of ECM and cytoskeletal genes, consistent with a migratory phenotype. Unlike trailing ENCDCs, the wavefront lacked expression of genes related to neuronal or glial maturation. As wavefront ENCDC genes were associated with migration and developmental immaturity, the genes that remain expressed in later progenitor populations may be particularly pertinent to understanding the maintenance of ENCDC progenitor characteristics. Dusp6 expression was specifically upregulated at the wavefront. Inhibiting DUSP6 activity prevented wavefront colonization of the hindgut, and inhibited the migratory ability of post-colonized ENCDCs from midgut and postnatal neurospheres. These effects were reversed by simultaneous inhibition of ERK signaling, indicating that DUSP6-mediated ERK inhibition is required for ENCDC migration in mouse and chick.

Gene-Function-Based Clusters Explore Intricate Networks of Gene Expression of Circulating Tumor Cells in Patients with Colorectal Cancer

Colorectal cancer (CRC) is a complex disease characterized by dynamically deregulated gene expression and crosstalk between signaling pathways. In this study, a new approach based on gene-function-based clusters was introduced to explore the CRC-associated networks of gene expression. Each cluster contained genes involved in coordinated regulatory activity, such as RAS signaling, the cell cycle process, transcription, or translation. A retrospective case-control study was conducted with the inclusion of 119 patients with histologically confirmed colorectal cancer and 308 controls. The quantitative expression data of 15 genes were obtained from the peripheral blood samples of all participants to investigate cluster-gene and gene-gene interactions. DUSP6, MDM2, and EIF2S3 were consistently selected as CRC-associated factors with high significance in all logistic models. CPEB4 became an insignificant factor only when combined with the clusters for cell cycle processes and for transcription. The CPEB4/DUSP6 complex was a prerequisite for the significance of MMD, whereas EXT2, RNF4, ZNF264, WEE1, and MCM4 were affected by more than two clusters. Intricate networks among MMD, RAS signaling factors (DUSP6, GRB2, and NF1), and translation factors (EIF2S3, CPEB4, and EXT2) were also revealed. Our results suggest that limited G1/S transition, uncontrolled DNA replication, and the cap-independent initiation of translation may be dominant and concurrent scenarios in circulating tumor cells derived from colorectal cancer. This gene-function-based cluster approach is simple and useful for revealing intricate CRC-associated gene expression networks. These findings may provide clues to the metastatic mechanisms of circulating tumor cells in patients with colorectal cancer.

Novel Endometrial Cancer Models Using Sensitive Metastasis Tracing for CXCR4-Targeted Therapy in Advanced Disease

Advanced endometrial cancer (EC) lacks therapy, thus, there is a need for novel treatment targets. CXCR4 overexpression is associated with a poor prognosis in several cancers, whereas its inhibition prevents metastases. We assessed CXCR4 expression in EC in women by using IHC. Orthotopic models were generated with transendometrial implantation of CXCR4-transduced EC cells. After in vitro evaluation of the CXCR4-targeted T22-GFP-H6 nanocarrier, subcutaneous EC models were used to study its uptake in tumor and normal organs. Of the women, 91% overexpressed CXCR4, making them candidates for CXCR4-targeted therapies. Thus, we developed CXCR4⁺ EC mouse models to improve metastagenesis compared to current models and to use them to develop novel CXCR4-targeted therapies for unresponsive EC. It showed enhanced dissemination, especially in the lungs and liver, and displayed 100% metastasis penetrance at all clinically relevant sites with anti-hVimentin IHC, improving detection sensitivity. Regarding the CXCR4-targeted nanocarrier, 60% accumulated in the SC tumor; therefore, selectively targeting CXCR4⁺ cancer cells, without toxicity in non-tumor organs. Our CXCR4⁺ EC models will allow testing of novel CXCR4-targeted drugs and development of nanomedicines derived from T22-GFP-H6 to deliver drugs to CXCR4⁺ cells in advanced EC. This novel approach provides a therapeutic option for women with metastatic, high risk or recurrent EC that have a dismal prognosis and lack effective therapies.

UPF1 contributes to the maintenance of endometrial cancer stem cell phenotype by stabilizing LINC00963

Endometrial cancer stem cells (ECSCs) play a vital role in endometrial cancer (EC) metastasis, relapse, and chemoresistance. However, the molecular mechanisms that sustain ECSCs remain elusive. Here, we showed that the expression of UPF1 was upregulated in EC tissues and ECSCs and correlated with poor clinicopathological characteristics. UPF1 silencing suppressed ECSC hallmarks, such as sphere formation ability, carboplatin resistance, migration and invasion, and cell cycle progression. UPF1 regulated the behavior and fate of ECSCs by stabilizing LINC00963. LINC00963 further shares the same miRNA response element with the core transcription factor SOX2 and relieved the suppression of SOX2 by miR-508-5p in self-renewing ECSCs. Notably, inhibition of UPF1 and LINC00963 in combination severely impaired the in vivo tumorigenic potential of ECSCs. We demonstrate that the UPF1/LINC00963/miR-508-5p/SOX2 axis has potential value in modulating ECSC maintenance, chemoresistance, and tumorigenesis in EC, which highlights a novel promising target for EC treatment.

Dusp6 immunohistochemistry is associated with the response of atypical endometrial hyperplasia and early endometrial cancer to conservative treatment

OBJECTIVE

Dual-specificity phosphatase 6 (Dusp6) was proposed as a predictive marker of response of atypical endometrial hyperplasia (AEH) and early endometrial cancer (EEC) to conservative treatment. However, its predictive accuracy has never been calculated. We aimed to define it in conservatively treated AEH and EEC.

METHODS

All patients <45 years with AEH or EEC and conservatively treated with hysteroscopic resection + LNG-IUD insertion from 2007 to 2018 were retrospectively assessed. Dusp6 immunohistochemical expression was assessed and dichotomized as "strong" vs "weak". Relative risk (RR) for "no regression" and "recurrence" or AEH/EEC was calculated. Predictive accuracy was calculated as sensitivity, specificity, positive and negative predictive values (PPV, NPV) and area under the curve (AUC) on receiver operating characteristic curve.

RESULTS

Thirty-six women were included. Weak Dusp6 immunohistochemical expression was significantly associated with increased risk of resistance to treatment, with a RR = 16 (P = 0.0074); predictive accuracy analysis showed sensitivity = 80%, specificity = 90%, PPV = 57.1%, NPV = 96.4%, AUC = 0.85. A weak Dusp6 expression was not significantly associated with the risk of recurrence after an initial regression (RR = 0.4; P = 0.53).

CONCLUSION

Weak Dusp6 expression appears as a significant predictor of resistance of AEH/EEC to fertility-sparing treatment, with moderate predictive accuracy. Weak Dusp6 expression is significantly associated with resistance of atypical endometrial hyperplasia or early endometrial cancer to fertility-sparing treatment, with moderate predictive accuracy.

Targeting Phosphatases and Kinases: How to Checkmate Cancer

Metastatic disease represents the major cause of death in oncologic patients worldwide. Accumulating evidence have highlighted the relevance of a small population of cancer cells, named cancer stem cells (CSCs), in the resistance to therapies, as well as cancer recurrence and metastasis. Standard anti-cancer treatments are not always conclusively curative, posing an urgent need to discover new targets for an effective therapy. Kinases and phosphatases are implicated in many cellular processes, such as proliferation, differentiation and oncogenic transformation. These proteins are crucial regulators of intracellular signaling pathways mediating multiple cellular activities. Therefore, alterations in kinases and phosphatases functionality is a hallmark of cancer. Notwithstanding the role of kinases and phosphatases in cancer has been widely investigated, their aberrant activation in the compartment of CSCs is nowadays being explored as new potential Achille's heel to strike. Here, we provide a comprehensive overview of the major protein kinases and phosphatases pathways by which CSCs can evade normal physiological constraints on survival, growth, and invasion. Moreover, we discuss the potential of inhibitors of these proteins in counteracting CSCs expansion during cancer development and progression.

DUSP7 inhibits cervical cancer progression by inactivating the RAS pathway

To determine the differentially expressed proteins (DEPs) between paired samples of cervical cancer (CC) and paracancerous tissue by quantitative proteomics and to examine the effects of DUSP7 expression on the tumorigenesis and progression of CC. Proteomic profiles of three paired samples of CC and paracancerous tissue were quantitatively analysed to identify DEPs. The relationship between DEP expression and patient clinicopathological characteristics and prognosis was evaluated. The effects of the selected DEPs on CC progression were examined in SIHA cells. A total of 129 DEPs were found. Western blot and immunohistochemistry (IHC) staining analyses confirmed the results from quantitative proteomic analysis showing that the selected DEP, HRAS, P-ERK1/2, and PLD1 levels were increased, whereas the DUSP7 level was decreased in CC tissue compared with the paired normal paracancerous tissues. The IHC results from the CC TMA analysis showed that the decreased expression of DUSP7 (p = 0.045 and 0.044) was significantly associated with a tumour size >2 cm and parametrial infiltration. In addition, the decreased expression of DUSP7 and increased expression of p-ERK1/2 were adversely related to patient relapse (p = 0.003 and 0.001) and survival (p = 0.034 and 0.006). The expression of HRAS and p-ERK1/2 was decreased in DUSP7-SIHA cells compared with NC-SIHA cells (p = 0.0003 and 0.0026). Biological functions in vitro, including invasion, migration and proliferation and tumour formation in vivo were decreased in DUSP7-SIHA cells (all p < 0.05) but increased in shDUSP7-SIHA cells (all p < 0.05). DUSP7 inhibits cervical cancer progression by inactivating the RAS pathway.

Cancer stem cell phosphatases

Cancer stem cells (CSCs) are involved in the initiation and progression of human malignancies by enabling cancer tissue self-renewal capacity and constituting the therapy-resistant population of tumor cells. However, despite the exhausting characterization of CSC genetics, epigenetics, and kinase signaling, eradication of CSCs remains an unattainable goal in most human malignancies. While phosphatases contribute equally with kinases to cellular phosphoregulation, our understanding of phosphatases in CSCs lags severely behind our knowledge about other CSC signaling mechanisms. Many cancer-relevant phosphatases have recently become druggable, indicating that further understanding of the CSC phosphatases might provide novel therapeutic opportunities. This review summarizes the current knowledge about fundamental, but yet poorly understood involvement of phosphatases in the regulation of major CSC signaling pathways. We also review the functional roles of phosphatases in CSC self-renewal, cancer progression, and therapy resistance; focusing particularly on hematological cancers and glioblastoma. We further discuss the small molecule targeting of CSC phosphatases and their therapeutic potential in cancer combination therapies.

PHF20 inhibition promotes apoptosis and cisplatin chemosensitivity via the OCT4‑p‑STAT3‑MCL1 signaling pathway in hypopharyngeal squamous cell carcinoma

Cisplatin is a widely used platinum‑based chemotherapeutic agent for hypopharyngeal squamous cell carcinoma (HSCC). However, resistance to cisplatin limits its use for the treatment of HSCC, and the underlying molecular mechanism requires further investigation. The present study performed functional assays to determine whether the expression of plant homeodomain finger protein 20 (PHF20) may be involved in the apoptosis and cisplatin resistance of HSCC. The expression levels of PHF20 were higher in cisplatin‑resistant HSCC cells compared with those in cisplatin‑sensitive cells. The inhibition of PHF20 suppressed cell viability but did not affect the migratory and invasive abilities of HSCC cells compared with those of negative control‑transfected cells. Furthermore, PHF20 inhibition reduced cell viability by enhancing apoptosis compared with those in the control cells in vitro. Notably, the inhibition of PHF20 sensitized HSCC cells to cisplatin, thus increasing apoptosis via the signal transducer and activator of transcription 3 (STAT3)‑myeloid cell leukemia‑1 (MCL1) pathway. Octamer‑binding transcription factor 4 (OCT4) overexpression restored phosphorylated STAT3‑MCL1‑mediated apoptosis induced by PHF20 inhibition. In vivo experiments confirmed that PHF20 silencing induced tumor growth and increased apoptosis in HSCC cells compared with those in the control cells. Thus, PHF20 inhibition may promote apoptosis and improve cisplatin chemosensitivity via the OCT4‑p‑STAT3‑MCL1 signaling pathway in HSCC.

Insight into the role of multiple signaling pathways in regulating cancer stem cells of gynecologic cancers

Mounting evidence has demonstrated that a myriad of developmental signaling pathways, such as the Wnt, Notch, Hedgehog and Hippo, are frequently deregulated and play a critical role in regulating cancer stem cell (CSC) activity in human cancers, including gynecologic malignancies. In this review article, we describe an overview of various signaling pathways in human cancers. We further discuss the developmental roles how these pathways regulate CSCs from experimental evidences in gynecologic cancers. Moreover, we mention several compounds targeting CSCs in gynecologic cancers to enhance the treatment outcomes. Therefore, these signaling pathways might be the potential targets for developing targeted therapy in gynecologic cancers.

Downregulation of 5-hydroxymethylcytosine is associated with the progression of cervical intraepithelial neoplasia

Around the world, cervical cancer is one of the most common neoplastic diseases among women, and the prognosis of patients in an advanced stage remains poor. To reduce the mortality rate of cervical cancer, early diagnosis and treatment are essential. DNA methylation is an important aspect of gene regulation, and aberrant DNA methylation contributes to carcinogenesis and cancer progression in various cancers. Although 5-methylcytosine (5mC) has been analyzed intensively, the function of 5-hydroxymethylcytosine (5hmC) has not been clarified. The purpose of our study was to identify the molecular biomarkers for early diagnosis of cervical tumors due to epigenetic alterations. To assess the clinical relevance of DNA methylation, we used immunohistochemistry (IHC) to characterize the level of 5hmC in 102 archived human cervical intraepithelial neoplasia (CIN) samples and cervical cancer specimens. The level of 5hmC was significantly decreased between CIN2 and CIN3. The progression of cervical tumors is caused by a reduction of TP53 and RB1 because of HPV infection. We observed that Tp53 and Rb1 were knocked down in mouse embryonic fibroblasts (MEF), a model of normal cells. The level of 5hmC was reduced in Tp53-knockdown cells, and the expression levels of DNA methyltransferase 1 (DNMT1) and ten-eleven translocation methylcytosine dioxygenase 1 (TET1) were induced. In contrast, there was no significant change in Rb1-knockdown cells. Mechanistically, we focused on apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) 3B (A3B) as a cause of 5hmC reduction after TP53 knockdown. In the human cell line HHUA with a wild-type TP53 gene, A3B was induced in TP53-knockdown cells, and A3B knockdown recovered 5hmC levels in TP53-knockdown cells. These data indicate that TP53 suppression leads to 5hmC reduction in part through A3B induction. Moreover, IHC showed that expression levels of A3B in CIN3 were significantly higher than those in both normal epithelium and in CIN2. In conclusion, 5hmC levels are decreased between CIN2 and CIN3 through the TP53-A3B pathway. Since A3B could impair genome stability, 5hmC loss might increase the chances of accumulating mutations and of progressing from CIN3 to cervical cancer. Thus, these epigenetic changes could predict whether CINs are progressing to cancer or disappearing.