Enhancement of Tumorigenicity, Spheroid Niche, and Drug Resistance of Pancreatic Cancer Cells in Three-Dimensional Culture System.

The three-dimensional (3D) cell culture technique has been applied comprehensively as a variable platform for medical research, biochemical signal pathway analysis, and evaluation of anti-tumor treatment response due to an excellent recapitulation of a tumor microenvironment (TME) in the in vitro cultured cancer cells. Pancreatic cancer (PaC) is one of the toughest malignancies with a complex TME and refractory treatment response. To comprehensively study the TME of PaC, there is an eager need to develop a 3D culture model to decompose the cellular components and their cross interactions. Herein, we establish a 3D PaC culture system with cancer stem cell (CSC) and scalability properties. To validate our model, we tested the individual PaC cell and the combined effects with cancer-associated fibroblasts (CAFs) on cancer tumorigenicity, the cellular interaction through the CXCR3/CXCL10 axis, and cellular responses reflection of anti-cancer treatments. With the help of our 3D technology, a simulated malignant spheroid with important stromal populations and TME physiochemical properties may be successfully recreated. It can be used in a wide range of preclinical research and helpful in advancing basic and translational cancer biology.

LncRNA MALAT1 Facilitates Ovarian Cancer Progression through Promoting Chemoresistance and Invasiveness in the Tumor Microenvironment.

Upregulation of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1, also known as nuclear-enriched abundant transcript 2 (NEAT2) or LINC00047) was found in various solid tumors, including epithelial ovarian cancer (EOC). MALAT1 is a long noncoding (lnc)RNA that regulates many functional signaling pathways, including tumorigenesis. Herein, we observed the consistent upregulation of MALAT1 in MYST4-overexpressing cell lines, while MALAT1 was frequently found to be upregulated in various types of clinical carcinoma tissues, especially EOC. To further investigate the lncRNA MALAT1 in EOC progression, the transduced overexpression of MALAT1 in EOC cell lines and cancer-associated fibroblasts (CAFs) was employed. We found that MALAT1 overexpression in EOC cell lines significantly increased drug resistance, cell migration, and invasion. Furthermore, the concomitant overexpression of MALAT1 in EOC cells and CAFs dramatically increased EOC cell invasion. Accordingly, a mechanistic investigation of MALAT1 overexpression in EOC cells showed that expressions of the cytokines interleukin (IL)-1ß and p-P38/p-NFκB/Cox2/prostaglandin E2 (PGE2) signaling were significantly increased, which stimulated inflammatory responses, whereas cell apoptosis was inhibited due to increased Bcl-2 levels and reduced Caspase3 levels. After MALAT1 was overexpressed in EOC cells, and the cyclin D1, p-PI3K, and p-Akt expressions increased, suggesting the promotion of tumor cell proliferation, while increased zinc finger E-box-binding homeobox-2 (ZEB2), yes-associated protein (YAP), and vimentin expression with E-cadherin downregulation indicated the enhancement of the epithelial-to-mesenchymal transition (EMT) in terms of metastasis, thereby triggering EOC progression. Together, our findings demonstrate how MALAT1 overexpression facilitates an oncogenic function through inhibiting tumor cell apoptosis, combined with increasing tumor cell inflammation, proliferation, and invasion in the EOC tumor microenvironment. MALAT1 is thus a potential diagnostic marker and therapeutic for this malignancy.

The Molecular Landscape Influencing Prognoses of Epithelial Ovarian Cancer.

Epithelial ovarian cancer (EOC) is one of the major increasing lethal malignancies of the gynecological tract, mostly due to delayed diagnosis and chemoresistance, as well as its very heterogeneous genetic makeup. Application of high-throughput molecular technologies, gene expression microarrays, and powerful preclinical models has provided a deeper understanding of the molecular characteristics of EOC. Therefore, molecular markers have become a potent tool in EOC management, including prediction of aggressiveness, prognosis, and recurrence, and identification of novel therapeutic targets. In addition, biomarkers derived from genomic/epigenomic alterations (e.g., gene mutations, copy number aberrations, and DNA methylation) enable targeted treatment of affected signaling pathways in advanced EOC, thereby improving the effectiveness of traditional treatments. This review outlines the molecular landscape and discusses the impacts of biomarkers on the detection, diagnosis, surveillance, and therapeutic targets of EOC. These findings focus on the necessity to translate these potential biomarkers into clinical practice.

Rare clinical manifestations of primary peritoneal serous carcinoma presenting as colorectal cancer: A report of two cases.

OBJECTIVE: To report two cases of for primary peritoneal serous carcinoma (PPSC) to present with gastrointestinal manifestations that mimic colorectal cancer. CASE REPORT: There were two patients with initial presentations of fatigue with iron deficiency anemia, and tenesmus with bloody stool. Tumors of the ascending colon and rectum were detected by colonofiberoscope, and pathologic reports of tumor biopsies revealed adenocarcinoma of suspected gynecologic origin. Both patients underwent optimal debulking surgery without macroscopic residual tumor, and then received adjuvant carboplatin and paclitaxel chemotherapy with bevacizumab. CONCLUSIONS: PPSC can clinically present like primary colorectal carcinoma. The differential diagnosis requires special staining of several markers for tumor tissues.

Characteristics of CD133-Sustained Chemoresistant Cancer Stem-Like Cells in Human Ovarian Carcinoma.

Cancer stem cells (CSCs) are considered to be the origin of ovarian cancer (OC) development, recurrence, and chemoresistance. We investigated changes in expression levels of the CSC biomarker, cluster of differentiation 133 (CD133), from primary OC cell lines to induction of CSC-spheres in an attempt to explore the mechanisms related to modulation of stemness, drug resistance, and tumorigenesis in CSCs, thus facilitating the search for new therapeutics for OC. The effect of CD133 overexpression on the induction of CSC properties was evaluated by sphere-forming assays, RT-qPCR, flow cytometry, cell viability assays, and in vivo xenograft experiments. Moreover, the potential signaling molecules that participate in CD133 maintenance of stemness were screened by RNA-sequencing. CD133 expression was upregulated during OCSC induction and chemotherapeutic drug treatment over time, which increased the expressions of stemness-related markers (SOX2, OCT4, and Nanog). CD133 overexpression also promoted tumorigenesis in NOD/SCID mice. Several signalings were controlled by CD133 spheres, including extracellular matrix receptor interactions, chemokine signaling, and Wnt signaling, all of which promote cell survival and cell cycle progression. Our findings suggest that CD133 possesses the ability to maintain functional stemness and tumorigenesis of OCSCs by promoting cell survival signaling and may serve as a potential target for stem cell-targeted therapy of OC.

Frequent CTNNB1 or PIK3CA Mutations Occurred in Endometrial Endometrioid Adenocarcinoma With High Levels of Microsatellite Instability and Loss of MSH2/MSH6 Expression.

BACKGROUND: DNA mismatch repair (MMR) proteins form 2 heterodimers-MutSα formed by MSH2 and MSH6, and MutLα by MLH1 and PMS2. In endometrial endometrioid adenocarcinomas, cases with MMR protein defect also usually harbor other recurrent genetic mutations of the neoplasm. However, it remains unknown whether defects of the 2 functionally different heterodimers are linked to mutations in different genes. We aimed to study the MMR protein expression, microsatellite instability (MSI), and other common genetic mutations of endometrial endometrioid adenocarcinoma. MATERIALS AND METHODS: We investigated the MSI status of 107 endometrial endometrioid adenocarcinoma patients. MMR protein expression, and mutation of KRAS, CTNNB1, and PIK3CA were also evaluated by immunohistochemistry and sequencing. RESULTS: An overall 34.6% (37/107) of endometrial endometrioid adenocarcinomas were MSI-H. All MSI-H tumors exhibited loss of MMR protein expression (loss of MLH1, PMS2, MSH6, and MSH2 was noted in 22, 25, 12, and 7 cases, respectively). CTNNB1, PIK3CA, and KRAS mutation were present in 9, 7, and 7 MSI-H tumors. Compared with patients with loss of PMS2 and/or MLH1 expression, patients with loss of MSH6 and/or MSH2 expression were associated with higher frequencies of CTNNB1 mutation (P=0.036) and PIK3CA mutation (P=0.025). CONCLUSIONS: In MSI-H endometrial endometrioid adenocarcinomas, different types of MMR protein deficiency indicate different molecular genetic alterations.

SRPX and HMCN1 regulate cancer­associated fibroblasts to promote the invasiveness of ovarian carcinoma.

Cancer­associated fibroblasts (CAFs) are known to be essential in cancer initiation and development. However, the role of CAFs in promoting ovarian cancer (OC) invasion remains to be fully elucidated. To address this in the present study, 49 clinical OC specimens were used to evaluate the roles of CAFs in promoting ovarian tumor migration and invasion and disease progression. It was found that the sushi repeat­containing protein, X­linked (SRPX) and hemicentin 1 (HMCN1) genes were significantly upregulated in CAFs from high­grade serous carcinoma (HGSC) and clear cell carcinoma (CCC) samples, the two major histological types of OC with frequently poor patient survival rates. The short hairpin (sh)RNA­mediated silencing of SRPX and HMCN1 in fibroblasts significantly suppressed the Transwell invasive activities of OC cells. Further experiments showed that SRPX and HMCN1 regulated the invasiveness of OC via the Ras homology family member A (RhoA) signaling pathway in fibroblasts. Therefore, the findings of the present study suggest that targeting the CAF genes, SRPX and HMCN1, can inhibit OC migration and invasion. These data highlight the importance of CAF­OC crosstalk signaling in cancer invasion and demonstrate the potential for improved efficacy of OC treatment by targeting CAF­SRPX/HMCN1.

Primary ovarian mucinous carcinoid tumor: A case report and review of literature.

OBJECTIVE: Only a few cases of primary ovarian mucinous carcinoid tumor have been documented in the literature till date. We present a case of primary ovarian mucinous carcinoid tumor, atypical type, and review the reported cases. CASE REPORT: A 33-year-old woman with a left ovarian tumor was diagnosed with primary ovarian mucinous carcinoid tumor, atypical type. She underwent left salpingo-oophorectomy and ipsilateral lymph node dissection. After 5 years, the tumor recurred on the right side, with large para-aortic lymphadenopathy that caused hydronephrosis. Complete surgical staging was performed, followed by nine cycles of weekly paclitaxel and gemcitabine. The tumor progressed after discontinuing the chemotherapy, and the patient died of disease 26 months after recurrence. CONCLUSION: Our patient demonstrated a more aggressive clinical course compared to that reported in previous literature. Based on this experience, complete surgical staging is highly recommended after the patient accomplished her fertility plan. Ovarian carcinoid tumors are relatively chemoresistant compared with epithelial ovarian cancers. The regimen of weekly paclitaxel and gemcitabine stabilized the disease but did not reach remission of the tumor. Further studies are required to determine the appropriate chemotherapy regimen.

Ex Vivo Expanded Human Vγ9Vδ2 T-Cells Can Suppress Epithelial Ovarian Cancer Cell Growth.

γδ-T-cells have attracted attention because of their potent cytotoxicity towards tumors. Most γδ-T-cells become activated via a major histocompatibility complex (MHC)-independent pathway by the interaction of their receptor, Natural Killer Group 2 Member D (NKG2D) with the tumor-specific NKG2D ligands, including MHC class I-related chain A/B (MICA/B) and UL16-binding proteins (ULBPs), to kill tumor cells. However, despite their potent antitumor effects, the treatment protocols specifically targeting ovarian tumors require further improvements. Ovarian cancer is one of the most lethal and challenging female malignancies worldwide because of delayed diagnoses and resistance to traditional chemotherapy. In this study, we successfully enriched and expanded γδ-T-cells up to ~78% from peripheral blood mononuclear cells (PBMCs) with mostly the Vγ9Vδ2-T-cell subtype in the circulation. We showed that expanded γδ-T-cells alone exerted significant cytotoxic activities towards specific epithelial-type OVCAR3 and HTB75 cells, whereas the combination of γδ-T cells and pamidronate (PAM), a kind of aminobisphosphonates (NBPs), showed significantly enhanced cytotoxic activities towards all types of ovarian cancer cells in vitro. Furthermore, in tumor xenografts of immunodeficient NSG mice, γδ-T-cells not only suppressed tumor growth but also completely eradicated preexisting tumors with an initial size of ~5 mm. Thus, we concluded that γδ-T-cells alone possess dramatic cytotoxic activities towards epithelial ovarian cancers both in vitro and in vivo. These results strongly support the potential of clinical immunotherapeutic application of γδ-T-cells to treat this serious female malignancy.

The overexpression of MYST4 in human solid tumors is associated with increased aggressiveness and decreased overall survival.

MYST4 (also called MORF and KAT6B) is one of the histone acetyltransferases with transcriptional regulatory activity. It was found to be overexpressed in ovarian cancer by a serial analysis of gene expression assays that focused on plant homeodomain-linked domain-containing genes. Compared to ovarian clear cell carcinomas and endometrioid carcinomas, MYST4 is significantly overexpressed in ovarian high-grade serous carcinomas (HGSCs) and was correlated with diminished patient survival in advanced stage HGSCs. Due to limited data on MYST4 in tumorigenesis and tumor progression, we explored the functional roles of MYST4 in human tumors. Besides the ovarian cancer cell line A2780, we chose two other types of human cancer cell lines expressing high mRNA levels of MYST4, SKBR3 and Huh7, for further in vitro investigation. Athymic nu/nu mice were utilized to facilitate the in vivo xenograft study. To search for potentially regulated genes, a microarray study comparing the expression profile before and after MYST4 knockdown was performed. Overexpression of MYST4 in HCCs was significantly associated with decreased survival. The knockdown of MYST4 significantly reduced cellular proliferation, migration, and cell cycle progression in all three cancer cell lines. Moreover, the knockdown of MYST4 in Huh7 cells suppressed tumor growth in a mouse xenograft model. Furthermore, based on our microarray study, we identified several downstream genes important in regulating tumor behaviors. Collectively, our results suggest that MYST4 is involved in cancer progression and contributes to a more aggressive behavior in human solid tumors. Targeting MYST4 represents an appealing strategy for the effective treatment of advanced solid tumors overexpressing MYST4.

Iron suppresses ovarian granulosa cell proliferation and arrests cell cycle through regulating p38 mitogen-activated protein kinase/p53/p21 pathway.

Iron is an essential nutrient that may exert toxic effects when it accumulates in tissues. Little is known regarding its effects on gonadal function. Both Fe2+ and Fe3+ could be released from iron deposition. We employed mouse nonluteinized granulosa cell for in vitro studies and human ovarian tissues for Prussian blue and immunohistochemical staining to identify the iron deposition and effect in vivo. After treatment with FeSO4-7H2O or FeCl3 in granulosa cell cultured with follicle-stimulating hormone (FSH) for 48 h, we found that Fe2+ significantly suppressed FSH-induced granulosa cell proliferation and arrested the cell cycle at the G2/M phase by cell proliferation assay and flow cytometry. Fe2+ significantly increased intracellular reactive oxygen species (ROS) and ferritin levels of mouse granulosa cells. The increases in p21 and p53 messenger RNA and protein expression facilitated by Fe2+ treatment in mouse granulosa cells were significantly suppressed by separate treatments with p53 small interfering RNA and p38 mitogen-activated protein kinase (MAPK) inhibitors. An ROS inhibitor downregulated Fe2+-induced increases in p38MAPK expression in mouse granulosa cells. Quantitative analysis of immunohistochemical staining revealed that human ovarian tissue sections with positive Prussian blue staining had lower levels of proliferating cell nuclear antigen expression, but higher levels of p21, p53, and CDC25C expression than those with negative Prussian blue staining. Conclusively, Fe2+ could directly arrest the cell cycle and inhibit granulosa cell proliferation by regulating the ROS-mediated p38MAPK/p53/p21 pathway. Therefore, iron can directly affect female gonadal function.

Cervical Papanicolaou Smears in Hematopoietic Stem Cell Transplant Recipients: High Prevalence of Therapy-Related Atypia during the Acute Phase.

Hematopoietic stem cell transplant (HSCT) recipients have a higher risk of cervical cancer. Papanicolaou (Pap) smear is the standard tool for screening cervical cancer, but there is limited research about the cervical cytology in HSCT recipients. Here, we retrospectively included adult female patients who underwent allogeneic or autologous HSCT at National Taiwan University Hospital during 2009 to 2015 and reviewed their Pap smears before and after HSCT. There were 248 allogeneic and 131 autologous HSCT recipients in our study. In allogeneic HSCT recipients, 38.7% (96 of 248) had pre-HSCT Pap smears and 17.1% (44 of 248) had post-HSCT Pap smears. In the autologous HSCT recipients, 35.1% (46 of 131) had pre-HSCT Pap smears and 13.7% (18 of 131) had post-HSCT Pap smears. Compared with allogeneic HSCT recipients without post-HSCT Pap smears, more recipients with post-HSCT Pap smears received bone marrow-derived stem cells (18.2% versus 4.9% respectively; P = .0077) and had longer overall survival (median overall survival, not reached versus 22.1 months; P < .0001). The abnormal rates of post-HSCT Pap smear were 13% (6 of 44) and 11% (2 of 18) in allogeneic and autologous recipients respectively, higher than in the general Taiwanese population (1.22%). Infections were rare in post-HSCT Pap smears. Of note, 11% (5 of 44) of post-HSCT Pap smears from allogeneic recipients showed therapy-related atypia, manifesting as enlarged hyperchromatic nuclei, vacuolated cytoplasm, and occasional tadpole-like cells. These atypical cytological features mimic precancerous lesions, but cervical biopsies and human papilloma virus tests were negative. The atypical cytological features resolved spontaneously in the subsequent follow-up Pap smears. On average, Pap smears with therapy-related atypia were sampled at day +77, significantly earlier than those without therapy-related atypia (P = .016). Therapy-related atypia was more frequent in post-HSCT Pap smears sampled within 100 days after HSCT (before day +100, 4 of 5, 80%, versus after day +100, 1 of 39, 2.56%; P = .0002). The strong temporal relationship suggests these atypical cytological changes resulted from conditioning regimen, most likely busulfan-containing chemotherapy. No therapy-related atypia were observed after total body irradiation or nonbusulfan-containing chemotherapy. In conclusion, therapy-related atypia was common in post-HSCT Pap smears sampled within 100 days after HSCT. Clinical information is critical for correct cytological diagnosis.

CCNE1 copy-number gain and overexpression identify ovarian clear cell carcinoma with a poor prognosis.

Ovarian clear cell carcinoma is a unique type of ovarian cancer, often derived from endometriosis, and advanced-stage disease has a dismal prognosis primarily due to the resistance to conventional chemotherapy. Previous studies have shown frequent somatic mutations in ARID1A, PIK3CA, hTERT promoter, and amplification of ZNF217; however, the molecular alterations that are associated with its aggressiveness remain largely unknown. This study examined and compared cyclin E1 expression in endometriosis-related ovarian tumors, with the aim of determining the relationship between hTERT mutations and ARID1A expression and evaluating the effects of these molecular alterations on patient survival. We performed immunohistochemistry on 207 tumors [clear cell carcinoma (n=120), endometrioid carcinoma (n=49), and seromucinous tumors (n=38)], followed by two-color fluorescence in situ hybridization (n=88) and compared with ARID1A expression and hTERT promoter mutations in the same samples. Cyclin E1 overexpression and CCNE1 copy-number gain occurred in 23.3% and 14.8% of ovarian clear cell carcinomas, respectively, but they were not detected in any of the other endometriosis-related tumors. All cases with CCNE1 copy-number gain demonstrated an intense cyclin E1 immunoreactivity (P<0.001). Cyclin E1 overexpression was positively correlated with hTERT promoter mutations (P=0.01), but not with the loss of ARID1A expression. A multivariate analysis revealed that CCNE1 overexpression predicts poor overall survival, even after adjusting for stage and age. Specifically, CCNE1 overexpression and copy-number gain were both correlated with a poor outcome in patients with stage I disease. Moreover, the subset with CCNE1 overexpression and ARID1A retention demonstrated the worst outcome. Our findings suggest that gene copy-number gain and upregulation of CCNE1 occur in ovarian clear cell carcinoma and are associated with a worse clinical outcome, dictating the survival of early-stage patients, and that these molecular alterations are unique to clear cell carcinoma among different types of endometriosis-related ovarian neoplasms.

Gastric-type adenocarcinoma in situ of uterine cervix: cytological and histopathological features of two cases.

Benign, premalignant, and malignant endocervical glandular lesions occasionally show a gastric phenotype. We report 2 cases of gastric-type adenocarcinoma in situ (AIS) of the endocervix, not associated with lobular endocervical glandular hyperplasia or gastric-type adenocarcinoma. Cytologically, both showed endocervical glands with slightly enlarged nuclei, distinctive nucleoli, pseudostratified strips, and intracytoplasmic golden yellow mucin. Histologically, both lesions were situated in preexisting endocervical glands and presented columnar cells with voluminous pale eosinophilic cytoplasm and evident nuclear atypia. In case 1, the lesion was located at the mid-zone of the endocervical canal and, in case 2, at the outer endocervical canal with extension to the transformation zone and prominent intestinal metaplasia. In both, the cells showed voluminous cytoplasm containing gastric-type mucin, stained red by combined alcian blue/periodic acid-Schiff stain. Immunohistochemically, both lesions were positive for HIK1083 and p53, while negative for p16 and ER. Human papilloma virus (HPV) DNA was not detected by polymerase chain reaction. Our cases illustrate that gastric-type AIS can occur without lobular endocervical glandular hyperplasia. The lesions can occur in the outer cervical canal and present extensive intestinal differentiation. Awareness of this rare type of endocervical glandular lesion is important since they are pathogenetically different from the more common HPV-associated lesions and may become more prevalent in the HPV-eradicating era.

Loss of switch/sucrose non-fermenting complex protein expression is associated with dedifferentiation in endometrial carcinomas.

Dedifferentiated endometrial carcinoma is an aggressive type of endometrial cancer that contains a mix of low-grade endometrioid and undifferentiated carcinoma components. We performed targeted sequencing of eight dedifferentiated carcinomas and identified somatic frameshift/nonsense mutations in SMARCA4, a core ATPase of the switch/sucrose non-fermenting (SWI/SNF) complex, in the undifferentiated components of four tumors. Immunohistochemical analysis confirmed the loss of SMARCA4 in the undifferentiated component of these four SMARCA4-mutated cases, whereas the corresponding low-grade endometrioid component showed retained SMARCA4 expression. An expanded survey of other members of the SWI/SNF complex showed SMARCB1 loss in the undifferentiated component of two SMARCA4-intact tumors, and all SMARCA4- or SMARCB1-deficient tumors showed concomitant loss of expression of SMARCA2. We subsequently examined the expression of SMARCA2, SMARCA4, and SMARCB1 in an additional set of 22 centrally reviewed dedifferentiated carcinomas and 31 grade 3 endometrioid carcinomas. Combining the results from the index and the expansion set, 15 of 30 (50%) of the dedifferentiated carcinomas examined showed either concurrent SMARCA4 and SMARCA2 loss (37%) or concurrent SMARCB1 and SMARCA2 loss (13%) in the undifferentiated component. The loss of SMARCA4 or SMARCB1 was mutually exclusive. All 31 grade 3 endometrioid carcinomas showed intact expression of these core SWI/SNF proteins. The majority (73%) of the SMARCA4/SMARCA2-deficient and half of SMARCB1/SMARCA2-deficient undifferentiated component developed in a mismatch repair-deficient molecular context. The observed spatial association between SWI/SNF protein loss and histologic dedifferentiation suggests that inactivation of these core SWI/SNF proteins may contribute to the development of dedifferentiated endometrial carcinoma.

Immunohistochemical study of endometrial high-grade endometrioid carcinoma with or without a concurrent low-grade component: implications for pathogenetic and survival differences.

AIMS: To compare the clinical and pathogenetic differences between high-grade (HG) endometrioid carcinomas with and without concurrent low-grade (LG) components. METHODS AND RESULTS: The expression of ARID1A, PTEN, p53 and mismatch repair (MMR) proteins in HG endometrioid carcinomas without (n = 19) or with (n = 22) concurrent LG endometrioid carcinomas was studied by immunohistochemistry. Microsatellite instability (MSI) was also tested in 31 cases. The frequencies of ARID1A loss, PTEN loss, MMR deficiency or MSI and aberrant p53 expression were 58%, 37%, 37% and 47% in pure HG tumours, and 77%, 45%, 55% and 32% in HG tumours with concurrent LG components (P = 0.07 for ARID1A; P > 0.1 for other proteins). Pure HG tumours had a higher frequency of the type II phenotype (positive for ARID1A, PTEN and MMR proteins; aberrant p53 expression) than HG tumours with concurrent LG components (21% versus 5%) (P = 0.2). The 5-year overall survival rate was worse for pure HG tumours (61.7%) than for HG tumours with concurrent LG components (93.3%) (P = 0.07). CONCLUSIONS: HG endometrioid carcinomas are heterogeneous in pathogenesis: some arise from LG endometrioid carcinomas via the type I pathway, whereas others may arise de novo through either the type I pathway or the type II pathway, and have a different prognosis. Thus, HG endometrioid carcinomas should be subclassified properly and treated accordingly.

Increased proliferation in atypical hyperplasia/endometrioid intraepithelial neoplasia of the endometrium with concurrent inactivation of ARID1A and PTEN tumour suppressors.

Uterine endometrioid carcinoma is the most common neoplastic disease in the female genital tract and develops from a common precursor lesion, atypical hyperplasia/endometrioid intraepithelial neoplasia (AH/EIN). Although the genomic landscape of endometrioid carcinoma has been recently revealed, the molecular alterations that contribute to tumour progression from AH/EIN to carcinoma remain to be elucidated. In this study, we used immunohistochemistry to determine if loss of expression of two of the most commonly mutated tumour suppressors in endometrioid carcinoma, PTEN and ARID1A, was associated with increased proliferation in AH/EIN. We found that 80 (70%) of 114 cases exhibited decreased or undetectable PTEN and 17 (15%) of 114 cases had focal loss of ARID1A staining. ARID1A loss was focal, while PTEN loss was diffuse, and all specimens with ARID1A loss had concurrent PTEN loss (p = 0.0003). Mapping the distribution of PTEN and ARID1A staining in the same specimens demonstrated that all AH/EIN areas with ARID1A loss were geographically nested within the areas of PTEN loss. A significant increase in the proliferative activity was observed in areas of AH/EIN with concurrent loss of PTEN and ARID1A compared to immediately adjacent AH/EIN areas showing only PTEN loss. In a cell culture system, co-silencing of ARID1A and PTEN in human endometrial epithelial cells increased cellular proliferation to a greater degree than silencing either ARID1A or PTEN alone. These results suggest an essential gatekeeper role for ARID1A that prevents PTEN inactivation from promoting cellular proliferation in the transition of pre-cancerous lesions to uterine endometrioid carcinoma.

Ileum and colon perforation following peritoneal dialysis-related peritonitis and high-dose calcium polystyrene sulfonate.

A rare but severe complication, intestinal necrosis, has been reported after sodium polystyrene sulfonate (SPS; Kayexalate) and sorbitol intake. Some case reports described bowel perforation following calcium polystyrene sulfonate (CPS; Kalimate) administration. We report a case of ileum and colon perforation following peritoneal dialysis-related peritonitis and high-dose Kalimate in a 59-year-old female patient. The patient had a history of hypertension, diabetes mellitus, and end-stage renal disease (ESRD). During hospitalization for peritoneal dialysis-related peritonitis, she developed hyperkalemia, and Kalimate was administered orally. However, severe abdominal distension and pain occurred just one day after Kalimate intake. An urgent surgery disclosed several perforations in the ileum and sigmoid colon. Pathology of the resected gut showed transmural necrosis and perforation with basophilic angulated crystals. The patient finally expired during hospitalization due to refractory septic shock.

The roles of ARID1A in gynecologic cancer.

One of the exciting findings in recent cancer genome studies is the discovery of somatic mutations in several chromatin remodeling genes. These studies not only illuminate the emerging roles of chromatin remodeling in the pathogenesis of human cancer but also provide molecular genetic basis of aberrant epigenomic regulation as one of the key mechanisms driving cancer development. This is because chromatin remodeling influences a variety of DNA activities such as replication, transcription, repair, methylation, and recombination. Among the mutated chromatin remodeling genes reported, ARID1A is frequently mutated in a variety of human cancers, especially in endometrium-related neoplasms including ovarian clear cell carcinoma, ovarian endometrioid carcinomas, and uterine endometrioid carcinomas, all of which arise from endometrial epithelium. This review will summarize the recent advances in studying the roles of ARID1A mutations in gynecologic cancers with special emphasis on how this new knowledge will further extend our understanding of the pathogenesis of endometrium-related carcinomas.

Loss of ARID1A expression correlates with stages of tumor progression in uterine endometrioid carcinoma.

ARID1A is a recently identified tumor suppressor that functions in chromatin remodeling. Inactivating mutations of ARID1A and loss of its expression most frequently occur in ovarian clear cell carcinoma, ovarian endometrioid carcinoma, and uterine endometrioid carcinoma. In this study, we performed a detailed immunostaining analysis of ARID1A in 246 cases including benign endometrium and endometrioid carcinoma at different stages of progression. Special attention was paid to recording intratumoral heterogeneity of clonal loss of ARID1A immunoreactivity. All normal endometria (n=51) and endometrial polyps (n=14) retained ARID1A expression. Among complex atypical hyperplasias (n=38), 16% exhibited clonal loss of ARID1A, but none showed complete loss. Among low-grade endometrioid carcinomas (n=88), 25% exhibited complete loss and 24% exhibited clonal loss. In contrast, 44% of high-grade endometrioid carcinomas (n=55) showed complete loss of ARID1A, and 9% exhibited clonal loss. We found that 19 high-grade carcinomas also contained concurrent low-grade carcinomas. In the high-grade areas, 63% exhibited complete loss and 11% exhibited clonal loss, whereas in the low-grade areas, 37% exhibited complete loss and 42% clonal loss. In 5 of these 19 cases, progressive loss of ARID1A from retention or clonal loss to complete loss was observed between the low-grade and high-grade areas. Overall, the percentage of complete ARID1A loss increased from 0% in complex atypical hyperplasia, to 25% in low-grade endometrioid carcinoma, to 44% in high-grade endometrioid carcinoma. These findings suggest that loss of ARID1A expression, presumably due to mutation, plays an important role in tumor progression of uterine endometrioid carcinoma.