BACKGROUND: The phosphatidylinositol 3 0 -kinase (PI3K) -AKT pathway is activated in many human cancers and plays a key role in cell proliferation and survival. A mutation (E17K) in the pleckstrin homology domain of the AKT1 results in constitutive AKT1 activation by means of localisation to the plasma membrane. The AKT1 (E17K) mutation has been reported in some tumour types (breast, colorectal, ovarian and lung cancers), and it is of interest which tumour types other than those possess the E17K mutation. METHODS: We analysed the presence of the AKT1 (E17K) mutation in 89 endometrial cancer tissue specimens and in 12 endometrial cancer cell lines by PCR and direct sequencing. RESULTS: We detected two AKT1 (E17K) mutations in the tissue samples (2 out of 89) and no mutations in the cell lines. These two AKT1 mutant tumours do not possess any mutations in PIK3CA, PTEN and K-Ras. INTERPRETATION: Our results and earlier reports suggest that AKT1 mutations might be mutually exclusive with other PI3K -AKTactivating alterations, although PIK3CA mutations frequently coexist with other alterations (such as HER2, K-Ras and PTEN) in several types of tumours.
Drosophila tumor suppressor Scribble has been identified as an apical-basolateral polarity determinant in epithelia. A human homolog of Drosophila Scribble, human Scribble (hScrib), has been identified as a protein targeted by human papillomavirus E6 for the ubiquitin-mediated degradation dependent on E6AP, a cellular ubiquitin-protein ligase. Human Scribble is classified as a LAP protein, having leucine-rich repeats (LRRs) and PDZ domains. We investigated whether hScrib, which is thought to have a role in polarity determination based on the data of its Drosophila homolog, is involved in cell-cycle regulation and proliferation control of epithelia. Transfection of hScrib inhibits cell-cycle progression from G1 to S phase, and it up-and down-regulates expression of adenomatous polyposis coli and cyclins A and D1, respectively. Knockdown of hScrib expression by siRNA leads to cell-cycle progression from G1 to S phase. We explored functional domain mapping to reveal which domains of hScrib are critical for its cellular proliferation control and localization at the basolateral membrane. We found that LRRs and PDZ domain 1 are indispensable for hScrib to inhibit cell growth by blocking cell-cycle progression and to keep its proper localization. These data indicate that basolateral membrane localization of hScrib is closely related to its proliferation control. Our findings suggest the possibility that hScrib is involved in signal transduction to negatively regulate cell proliferation by localizing at the basolateral membrane of epithelial cells through LRRs and PDZ domains. Loss of cell polarity due to aberrant expression and localization of junctional proteins causes overgrowth of epithelia.(2) Mutation of a tumor suppressor gene whose encoded protein regulates cell-cycle progression is also characteristic of cancer tissues. Maintenance of tissue polarity and regulation of cell cycle are tightly linked to keep normal growth control and differentiation in epithelia.(3) Loss of tissue architecture and disruption of the cell-cycle control system leads to uncontrolled proliferation of epithelial cells and subsequent tumor formation. Drosophila tumor suppressor Scribble has recently been identified as an apical-basal polarity determinant in epithelia.(5) Drosophila Scribble localizes at the septate junction, which is functionally identical to the vertebrate tight junction, and loss of scribble mutation causes mislocalization of adherens junction to the basolateral membrane.(5) Follicle cells homozygous for scribble mutation are rounded, rather than columnar, and are often multilayered, rather than sheet-like. (6) In Drosophila scribble mutant, disorganized epithelial tissue overproliferates and causes massive tumors in imaginal discs, brain, and follicles. (6) Recently, scribble has been identified as a novel regulator of S-phase entry in Drosophila by a genetic screen for dominant hypomorphic cyclin E mutation. The human homolog of Drosophila tumor suppressor Scribble, hScrib, has recently been identified as a target of...
Endometrial cancer is a ubiquitous gynecological disease with increasing global incidence. Therefore, despite the lack of an established screening technique to date, early diagnosis of endometrial cancer assumes critical importance. This paper presents an artificial-intelligence-based system to detect the regions affected by endometrial cancer automatically from hysteroscopic images. In this study, 177 patients (60 with normal endometrium, 21 with uterine myoma, 60 with endometrial polyp, 15 with atypical endometrial hyperplasia, and 21 with endometrial cancer) with a history of hysteroscopy were recruited. Machine-learning techniques based on three popular deep neural network models were employed, and a continuity-analysis method was developed to enhance the accuracy of cancer diagnosis. Finally, we investigated if the accuracy could be improved by combining all the trained models. The results reveal that the diagnosis accuracy was approximately 80% (78.91–80.93%) when using the standard method, and it increased to 89% (83.94–89.13%) and exceeded 90% (i.e., 90.29%) when employing the proposed continuity analysis and combining the three neural networks, respectively. The corresponding sensitivity and specificity equaled 91.66% and 89.36%, respectively. These findings demonstrate the proposed method to be sufficient to facilitate timely diagnosis of endometrial cancer in the near future.
Abstract. Cyclin D1 is an important regulator of cell cycle progression. Phosphorylation of cyclin D1 at Thr286 by GSK3β triggers its nuclear export and cytoplasmic proteolysis via the 26S proteasome. Cyclin D1 overexpression is a common event in various types of human cancers; however, reports of mutations are extremely rare. We analyzed mutations of the cyclin D1 gene, CCND1, in 88 endometrial cancer tissue specimens and detected mutations in 2 cases (2.3%). Both were unreported mutations with substitution of threonine to isoleucine at codon 286 (T286I). These two tumors harbored coexisting mutations in K-ras, PIK3CA and/or PTEN and showed accumulation of cyclin D1 in the nucleus by immunohistochemistry. Furthermore, we analyzed the functions of mutant cyclin D1 (T286I) by luciferase assays, immunofluorescence, western blotting and clonogenic cell survival assays in HEK-293T cells. We found that exogenous mutant cyclin D1 (T286I) accumulated in the nuclei in HEK-293T cells, and that it inhibited the expression of pRb. Additionally, the number of colonies was increased by introduction of mutant cyclin D1 (T286I) compared to that of wild-type cyclin D1. In conclusion, we identified an unreported CCND1 mutation (T286I) in two endometrial cancers and revealed that the mutation was functional for inducing cell proliferation in human cells.
A diagnostic biopsy for endometrial cancer is performed via dilation and curettage (D&C). However, D&C may miss endometrial cancer lesions due to of its ‘blind’ approach. Hysteroscopy is a useful method that can be used to detect endometrial cancer lesions. In addition, office hysteroscopy is easy to be scheduled and does not require anesthesia. The patient was a 40-year-old woman with suspected endometrial cancer; however, it could not be diagnosed by D&C and biopsy using hysteroscopy during hospitalization. Office hysteroscopy during the proliferative phase indicated that the suspicious endometrial cancerous lesion was minimal at the isthmus of the uterus with atypical vessels and a white spot, for which biopsy was performed. Pathological diagnosis was endometrioid carcinoma with squamous differentiation, G1. Therefore, total laparoscopic hysterectomy, bilateral salpingo-oophorectomy and pelvic lymphadenectomy were performed. In this case, it was difficult to detect minimal lesion in the secretory phase because the endometrial thickness hid the endometrial cancer. It is easy to perform office hysteroscopy in the proliferative phase. This case indicated that office hysteroscopy is a useful method to diagnose and perform biopsy for minimal lesions.
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