Progesterone inhibits endometrial cancer growth by inhibiting glutamine metabolism through ASCT2.

Endometrial carcinoma (EC) is a common malignancy that originates from the endometrium and grows in the female reproductive system. Surgeries, as current treatments for cancer, however, cannot meet the fertility needs of young women patients. Thus, progesterone (P4) therapy is indispensable due to its effective temporary preservation of female fertility. Many cancer cells are often accompanied by changes in metabolic phenotypes, and abnormally dependent on the amino acid glutamine. However, whether P4 exerts an effect on EC via glutamine metabolism is unknown. In the present study, we found that P4 could inhibit glutamine metabolism in EC cells and down-regulate the expression of the glutamine transporter ASCT2. This regulation of ASCT2 affects the uptake of glutamine. Furthermore, the in vivo xenograft studies showed that P4 inhibited tumor growth and the expression of key enzymes involved in glutamine metabolism. Our study demonstrated that the direct regulation of glutamine metabolism by P4 and its anticancer effect was mediated through the inhibition of ASCT2. These results provide a mechanism underlying the effects of P4 therapy on EC from the perspective of glutamine metabolism.

Melatonin suppresses tumor proliferation and metastasis by targeting GATA2 in endometrial cancer.

Endometrial cancer (EC) is a reproductive system disease that occurs in perimenopausal and postmenopausal women. However, its etiology is unclear. Melatonin (MT) has been identified as a therapeutic agent for EC; however, its exact mechanism remains unclear. In the present study, we determined that GATA-binding protein 2 (GATA2) is expressed at low levels in EC and regulated by MT. MT upregulates the expression of GATA2 through MT receptor 1A (MTNR1A), whereas GATA2 can promote the expression of MTNR1A by binding to its promoter region. In addition, in vivo and in vitro experiments showed that MT inhibited the proliferation and metastasis of EC cells by upregulating GATA2 expression. The protein kinase B (AKT) pathway was also affected. In conclusion, these findings suggest that MT and GATA2 play significant roles in EC development.

Icaritin inhibits endometrial carcinoma cells by suppressing O-GlcNAcylation of FOXC1.

BACKGROUND: Icaritin has a wide range of pharmacological activities, including significant an-titumor activity. However, the mechanism of action of icaritin in endometrial cancer (UCEC) remains unknown. FOX proteins are a highly conserved transcription factor superfamily that play important roles in epithelial cell differentiation, tumor metastasis, angiogenesis, and cell cycle regulation. FOXC1 is an important member of the FOX protein family. FOXC1 is aberrantly expressed in endometrial cancer and may play a role in the migration and invasion of endometrial cancer; however, its mechanism of action has not yet been reported. O-GlcNAc glycosylation is a common post-translational modification. In endometrial cancer, high levels of O-GlcNAcylation promote cell proliferation, migration, and invasion. Cancer development is often accompanied by O-GlcNAc modification of proteins; however, O-GlcNAc modification of the transcription factor FOXC1 has not been reported to date. PURPOSE: To investigate the inhibitory effects of icaritin on RL95-2 and Ishikawa endometrial cancer cells in vitro and in vivo and to elucidate the possible molecular mechanisms. METHODS/STUDY DESIGN: CCK8, colony formation, migration, and invasion assays were used to determine the inhibitory effects of icaritin on endometrial cancer cells in vitro. Cell cycle regulation was assayed by flow cytometry. Protein levels were measured based on western blotting. The level of FOXC1 expression in endometrial cancer tissues was determined by immunohistochemistry. To assess whether icaritin also has activity in vivo, its effect on tumor xenografts was evaluated. RESULTS: Immunohistochemical analysis of clinical samples revealed that FOXC1 expression was significantly higher in endometrial cancer tissues than in normal tissues. Downregulation of FOXC1 inhibited the proliferative, colony formation, migration, and invasive abilities of RL95-2 and Ishikawa endometrial cancer cells. Icaritin inhibited the proliferation, colony formation, migration, and invasion of endometrial cancer cells and blocked the cell cycle in S phase. Icaritin affected O-GlcNAc modification of FOXC1 and thus the stability of FOXC1, which subsequently triggered the inhibition of endometrial cancer cell proliferation. CONCLUSION: The anti-endometrial cancer effect of icaritin is related to the inhibition of abnormal O-GlcNAc modification of FOXC1, which may provide an important theoretical foundation for the use of icaritin against endometrial cancer.

Emerging field: O-GlcNAcylation in ferroptosis.

In 2012, researchers proposed a non-apoptotic, iron-dependent form of cell death caused by lipid peroxidation called ferroptosis. During the past decade, a comprehensive understanding of ferroptosis has emerged. Ferroptosis is closely associated with the tumor microenvironment, cancer, immunity, aging, and tissue damage. Its mechanism is precisely regulated at the epigenetic, transcriptional, and post-translational levels. O-GlcNAc modification (O-GlcNAcylation) is one of the post-translational modifications of proteins. Cells can modulate cell survival in response to stress stimuli, including apoptosis, necrosis, and autophagy, through adaptive regulation by O-GlcNAcylation. However, the function and mechanism of these modifications in regulating ferroptosis are only beginning to be understood. Here, we review the relevant literature within the last 5 years and present the current understanding of the regulatory function of O-GlcNAcylation in ferroptosis and the potential mechanisms that may be involved, including antioxidant defense system-controlled reactive oxygen species biology, iron metabolism, and membrane lipid peroxidation metabolism. In addition to these three areas of ferroptosis research, we examine how changes in the morphology and function of subcellular organelles (e.g., mitochondria and endoplasmic reticulum) involved in O-GlcNAcylation may trigger and amplify ferroptosis. We have dissected the role of O-GlcNAcylation in regulating ferroptosis and hope that our introduction will provide a general framework for those interested in this field.

Analysis of genetic profiling, pathomics signature, and prognostic features of primary lymphoepithelioma-like carcinoma of the renal pelvis.

The genetic features of primary lymphoepithelioma-like carcinoma (LELC) of the upper urinary tract have not been systematically explored. In this study, tumor mutation profiling was performed using whole-genome sequencing in two patients with LELC of the renal pelvis. Novel candidate variants relevant to known disease genes were selected using rare-variant burden analysis. Subsequently, a population-based study was performed using the Surveillance, Epidemiology, and End Results (SEER), PubMed, MEDLINE, Embase, and Scopus databases to explore clinical features and prognostic risk factors. Immunohistochemical analysis revealed seven positive cytokeratin-associated markers in tumor cells and five positive lymphocyte-associated markers in and around the tumor area. Sub-sequently, we identified KDM6A as the susceptibility gene and LEPR as the driver gene by Sanger sequencing in case 2 of LELC of the renal pelvis. Three mutation sites of the existing targeted drugs were screened: CA9, a therapeutic target for zonisamide; ARVCF, a therapeutic target for bupropion; and PLOD3, a therapeutic target for vitamin C. In a population-based study, patients with primary LELC of the upper urinary tract had clinical outcomes similar to those of patients with primary upper urinary tract urothelial carcinoma (UUT-UC) before and after propensity score matching at 1 : 5. Focal subtype was an independent prognostic factor for the overall survival of patients with LELC of the upper urinary tract. The carcinogenesis of primary LELC may be due to different genetic variations, including single-nucleotide variants, insertion and deletions, structural variations, and repeat regions, which may provide the basis for clinical diagnosis and treatment. The prognosis of LELC in the upper urinary tract is similar to that of UUT-UC. We suggest that the focal subtype can serve as a prognostic factor for LELC of the upper urinary tract; however, further studies are required to confirm this.

Identification of distinct genomic features reveals frequent somatic AHNAK and PTEN mutations predominantly in primary malignant melanoma presenting in the ureter.

BACKGROUND: Primary malignant melanoma of the ureter is extremely rare. Genetic variants to the increased risk of developing the disease have not yet been investigated. METHODS: Tumour mutation profiling for primary malignant melanoma of the ureter was performed by whole-exome sequencing. Immunohistochemistry was performed to verify histopathological features and the variants of predisposing genes and driver mutation genes. Furthermore, we conducted a literature review and Surveillance, Epidemiology and End Result-based study by searching public databases. RESULTS: We identified 38 somatic single nucleotide variants and 9 somatic insertions and deletions (INDELs) in tumour specimens. After filtering with the Cancer Gene Census database, seven predisposing genes and two driver mutation genes were identified. Moreover, the immunohistochemical profile showed that tumour cells were positive for Melan-A, melanoma gp100 human melanoma black 45 (HMB45), S100 beta and P53. The expression levels of two driver mutation genes (phosphatase and tensin homolog (PTEN) and desmoyokin (AHNAK) and five predisposing genes (AT-rich interaction domain 1B (ARID1B), catalase, eukaryotic translation initiation factor 4 gamma 3 (EIF4G3), ANK3 and collagen type I) were significantly downregulated in tumour tissues compared to paracancerous tissues. In the literature review and Surveillance, Epidemiology and End Results-based study, patients with primary malignant melanoma of the urinary tract had worse clinical outcomes than patients with primary urothelial carcinoma after 1:2 propensity score matching (P = 0.010). Additionally, Cox multivariate analysis for patients with primary malignant melanoma of the urinary tract indicated that distant metastasis (hazard ratio = 1.185; P = 0.044) was an independent predictor for overall survival, and tumour focality (hazard ratio = 0.602; P = 0.017) and non-surgery (hazard ratio = 0.434; P = 0.003) were independent factors for tumour progression. CONCLUSIONS: Our study is the first to provide evidence that the distinct phenotypes of primary malignant melanoma of the ureter may be due to different genetic variations. The prognosis of primary malignant melanoma of the urinary tract was poorer than that of primary urothelial carcinoma of the urinary tract.

Caveolin-1 knockout mice have altered serum N-glycan profile and sialyltransferase tissue expression.

Caveolin-1 (Cav-1) is a constitutive protein within caveolar membranes. Previous studies from our group and others indicated that Cav-1 could mediate N-glycosylation, α2,6-sialylation, and fucosylation in mouse hepatocarcinoma cells in vitro. However, little is known about the effect of Cav-1 expression on glycosylation modifications in vivo. In this study, the N-glycan profiles in serum from Cav-1-/- mice were investigated by lectin microarray and mass spectrometric analysis approaches. The results showed that levels of multi-antennary branched, α2,6-sialylated, and galactosylated N-glycans increased, while high-mannose typed and fucosylated N-glycans decreased in the serum of Cav-1-/- mice, compared with that of wild-type mice. Furthermore, the real-time quantitative PCR analysis indicated that α2,6-sialyltransferase gene expression decreased significantly in Cav-1-/- mouse organ tissues, but α2,3- and α2,8-sialyltransferase did not. Of them, both mRNA and protein expression levels of the ß-galactoside α2,6-sialyltransferase 1 (ST6Gal-I) had dramatically reduced in Cav-1-/- mice organ tissues, which was consistent with the α2,6-sialyl Gal/GalNAc level reduced significantly in tissues instead of serum from Cav-1-/- mice. These results provide for the first time the N-glycans profile of Cav-1-/- mice serum, which will facilitate understanding the function of Cav-1 from the perspective of glycosylation.

Paired-like homeodomain transcription factor 2 affects endometrial cell function and embryo implantation through the Wnt/ß-catenin pathway.

The successful implantation of embryos is crucial for pregnancy in mammals. This complex process is inevitably dependent on the development of the endometrium. The paired-like homeodomain transcription factor 2 (PITX2) is involved in a variety of biological processes, but whether it is involved in embryo implantation has not been reported. In this study, we aimed to investigate uterine expression and regulation of PITX2 during implantation. We found that PITX2 was elevated in the human endometrium in the secretory phase. The results of the pregnant mouse models showed that PITX2 expression was spatiotemporal in mouse endometrial tissue throughout peri-implantation period, and it was significantly upregulated at the time of implantation. Interestingly, PITX2 was mainly localized to the glandular epithelium cells on D2.5-3.5 of pregnancy, while D5.5-6.5 was largely expressed in stromal cells. In vitro, PITX2 regulated endometrial cells proliferation, migration, invasion, and other functions through the Wnt/ß-catenin signaling pathway. In addition, a significant decrease in the rate of embryo implantation was observed after injecting PITX2 small interfering RNA into the uterine horn. These results demonstrate the effects of PITX2 on the physiological function of endometrial cells and embryo implantation, suggesting a role in the endometrial regulatory mechanism during implantation.

Whole-Exome Sequencing Reveals New Potential Mutations Genes for Primary Mucosa-Associated Lymphoid Tissue Lymphoma Arising From the Kidney.

Low-grade B cell lymphomas of mucosa-associated lymphoid tissue (MALT) lymphomas involving the kidney were extremely rare, genetic alteration or molecular features was not yet explored, which may lead to limited choices for postoperative adjuvant or targeted. Whole-exome sequencing based tumor mutation profiling was performed on the tumor sample from a 77-year-old female presenting with discomfort at the waist was pathologically diagnosed as MALT lymphomas in the right kidney. We identified 101 somatic SNVs, and the majority of the identified SNVs were located in CDS and intronic regions. A total of 190 gain counts of CNVs with a total size of 488,744,073 was also investigated. After filtering with the CGC database, seven predisposing genes (ARID4A, COL2A1, FANCL, ABL2, HSP90AB1, FANCA, and DIS3) were found in renal MALT specimen. Furthermore, we compared somatic variation with known driver genes and validated three mutational driver genes including ACSL3, PHOX2B, and ADCY1. Sanger sequencing of germline DNA revealed the presence of a mutant base T of PHOX2B and a mutant base C of ADCY1 in the sequence, which were discovered for the first time in MALT lymphomas involving the kidney. Moreover, immunohistochemical analysis revealed that tumor cells were positive for CD20, CD79a, PAX5, CD21, and CD23, and expression of CD3, CD5, and CD8 were observed in reactive T lymphocytes surrounding tumor cells. These findings illustrated that concurrent aberrant PHOX2B and ADCY1 signaling may be a catastrophic event resulting in disease progression and inhibition of the putative driver mutations may be alternative adjuvant therapy for MALT lymphoma in the kidney which warrants further clinical investigation.

MicroRNA­21 contributes to renal cell carcinoma cell invasiveness and angiogenesis via the PDCD4/c­Jun (AP­1) signalling pathway.

Accumulating evidence has demonstrated that microRNAs are associated with malignant biological behaviour, including tumorigenesis, cancer progression and metastasis via the regulation of target gene expression. Our previous study demonstrated that programmed cell death protein 4 (PDCD4), which is a tumour suppressor gene, is a target of microRNA­21 (miR­21), which affects the proliferation and transformation capabilities of renal cell carcinoma (RCC) cells. However, the role of miR­21 in the molecular mechanism underlying the migration, invasion and angiogenesis of RCC remains poorly understood. The effects of miR­21 on the invasion, migration and angiogenesis of RCC cells was determined through meta­analysis and regulation of miR­21 expression in vitro. After searching several databases, 6 articles including a total of 473 patients met the eligibility criteria for this analysis. The combined results of the meta­analysis revealed that increased miR­21 expression was significantly associated with adverse prognosis in patients with RCC, with a pooled hazard ratio estimate of 1.740. In in vitro experiments, we demonstrated that a miR­21 inhibitor decreased the number of migrating and invading A498 and 786­O RCC cells, along with a decrease in PDCD4, c­Jun, matrix metalloproteinase (MMP)2 and MMP9 expression. Additionally, inhibition of miR­21 was revealed to reduce tube formation and tube junctions in the endothelial cell line HMEC­1 by affecting the expression of angiotensin­1 and vascular endothelial growth factor A, whereas PDCD4 small interfering RNA exerted opposite effects on the same cells. Overall, these findings, along with evidence­based molecular biology, demonstrated that miR­21 expression promoted the migration, invasion and angiogenic abilities of RCC cells by directly targeting the PDCD4/c­Jun signalling pathway. The results may help elucidate the molecular mechanism underlying the development and progression of RCC and provide a promising target for microRNA­based therapy.

O­GlcNAc modification influences endometrial receptivity by promoting endometrial cell proliferation, migration and invasion.

O­linked ß­N­acetylglucosamine (O­GlcNAc) modification is a dynamic post­translational modification process that is involved in many crucial biological processes, including cell cycle regulation, nutrient metabolism and extracellular signaling. This dynamic modification is dependent on the ambient glucose concentration and is catalyzed and removed by O­GlcNAc transferase (OGT) and O­GlcNAcase (OGA), respectively. The present study aimed to determine the role of O­GlcNAcylation during embryo implantation by inhibiting or enhancing its function and expression. The results revealed that the expression of O­GlcNAc­modified proteins in the human secretory endometrium was higher than that of the endometrium during the proliferative phase, as determined via western blotting and immunohistochemistry. Additionally, the level of endometrial O­GlcNAc modification increased gradually from the pre­receptive to the receptive phase, which was then decreased during the non­receptive phase. In endometrial cells, RNA interference was utilized to reduce the expression of two key O­GlcNAc synthesis and decomposition enzymes, OGT and OGA, to indirectly increase or decrease levels of O­GlcNAc modification. The results revealed that increasing the level of O­GlcNAc modification enhanced cellular proliferation, migration, invasion and adhesion, thereby promoting embryo implantation. It is hypothesized that O­GlcNAc modification serves an important role in the regulation of endometrial receptivity and embryo implantation. The results of the present study may have important implications for the understanding of female fertility and may help improve infertility treatments.

The impact of advanced proteomics in the search for markers and therapeutic targets of bladder cancer.

Bladder cancer is the most common cancer of the urinary tract and can be avoided through proper surveillance and monitoring. Several genetic factors are known to contribute to the progression of bladder cancer, many of which produce molecules that serve as cancer biomarkers. Blood, urine, and tissue are commonly analyzed for the presence of biomarkers, which can be derived from either the nucleus or the mitochondria. Recent advances in proteomics have facilitated the high-throughput profiling of data generated from bladder cancer-related proteins or peptides in parallel with high sensitivity and specificity, providing a wealth of information for biomarker discovery and validation. However, the transmission of screening results from one laboratory to another remains the main disadvantage of these methods, a fact that emphasizes the need for consistent and standardized procedures as suggested by the Human Proteome Organization. This review summarizes the latest discoveries and progress of biomarker identification for the early diagnosis, projected prognosis, and therapeutic response of bladder cancer, informs the readers of the current status of proteomic-based biomarker findings, and suggests avenues for future work.

Is Overexpression of Ki-67 a Prognostic Biomarker of Upper Tract Urinary Carcinoma? A Retrospective Cohort Study and Meta-Analysis.

BACKGROUND: Upper tract urinary carcinoma (UTUC) is a relatively uncommon but aggressive disease. The Ki-67 antigen is a classic marker of cellular proliferation, but there is still controversy regarding the significance and importance of Ki-67 in tumor progression. METHODS: In this study, we first detected Ki-67 expression in UTUC patients by immunohistochemistry (IHC). Subsequently, we quantitatively combined the results with those from the published literature in a meta-analysis after searching several databases. RESULTS: IHC results demonstrated that patients with muscle-invasive tumors (T2-T4) had higher Ki-67 expression than those with non-muscle-invasive tumors (Tis-T1), suggesting that high Ki-67 expression may be associated with the aggressive form of UTUC. Kaplan-Meier curves showed that patients with high Ki-67 expression had significantly poorer cancer-specific survival (CSS) and disease-free survival (DFS). Furthermore, multivariate analysis suggested that Ki-67 expression was an independent prognostic factor for CSS (hazard ratio, HR=3.196) and DFS (HR=3.517) in UTUC patients. Then, a meta-analysis of the published literature investigating Ki-67 expression and its effects on UTUC prognosis was conducted. After searching the PubMed, Medline, Embase, Cochrane Library and Scopus databases, 12 articles met the eligibility criteria for this analysis. The eligible studies included a total of 1740 patients with a mean number of 82 patients per study (range, 38-475). The combined results showed that increased Ki-67 levels were associated with poor survival and disease progression, with a pooled HR estimate of 2.081 and 2.791, respectively. In subgroup analysis, the pooled HR was statistically significant for cancer-specific survival (HR=2.276), metastasis-free survival (HR=3.008) and disease-free survival (HR=6.336). CONCLUSIONS: In conclusion, high Ki-67 expression was associated with poor survival in patients with UTUC, as well as a high risk of disease progression, although these findings need to be interpreted with caution. Large-scale, adequately designed, prospective trials are needed to further confirm the value of Ki-67 in prognosis of UTUC patients.

GalNAc-T4 putatively modulates the estrogen regulatory network through FOXA1 glycosylation in human breast cancer cells.

GALNT4 belongs to a family of N-acetylgalactosaminyltransferases, which catalyze the transfer of GalNAc to Serine or Threonine residues in the initial step of mucin-type O-linked protein glycosylation. This glycosylation type is the most complex post-translational modification of proteins, playing important roles during cellular differentiation and in pathological disorders. Most of the breast cancer subtypes are estrogen receptor positive, and hence, the estrogen pathway represents a key regulatory network. We investigated the expression of GalNAc-T4 in a panel of mammary epithelial cell lines and found its expression is associated with the estrogen status of the cells. FOXA1, a key transcription factor, functions to promote estrogen responsive gene expression by acting as a cofactor to estrogen receptor alpha (ERα), but all the aspects of this regulatory mechanism are not fully explored. This study found that knockdown of GALNT4 expression in human breast cancer cells attenuated the protein expression of ERα, FOXA1, and Cyclin D1. Further, our immunoprecipitation assays depicted the possibility of FOXA1 to undergo O-GalNAc modifications with a decrease of GalNAc residues in the GALNT4 knockdown cells and also impairment in the FOXA1-ERα association. Rescuing GALNT4 expression could restore the interaction as well as the glycosylation of FOXA1. Together, these findings suggest a key role for GalNAc-T4 in the estrogen pathway through FOXA1 glycosylation.