BRCA1/2 reversion mutations in a pan-cancer cohort.

Tumor sensitivity to platinum (Pt)-based chemotherapy and poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors is increased by homologous recombination deficiency-causing mutations; in particular, reversion mutations cause drug resistance by restoring protein function. Treatment response is predicted by breast cancer susceptibility gene 1/2 (BRCA1/2) mutations; however, BRCA1/2 reversion mutations have not been comprehensively studied in pan-cancer cohorts. We aimed to characterize BRCA1/2 reversion mutations in a large pan-cancer cohort of Japanese patients by retrospectively analyzing sequencing data for BRCA1/2 pathogenic/likely pathogenic mutations in 3738 patients with 32 cancer types. We identified somatic mutations in tumors or circulating cell-free DNA that could restore the ORF of adverse alleles, including reversion mutations. We identified 12 (0.32%) patients with somatic BRCA1 (n = 3) and BRCA2 (n = 9) reversion mutations in breast (n = 4), ovarian/fallopian tube/peritoneal (n = 4), pancreatic (n = 2), prostate (n = 1), and gallbladder (n = 1) cancers. We identified 21 reversion events-BRCA1 (n = 3), BRCA2 (n = 18)-including eight pure deletions, one single-nucleotide variant, six multinucleotide variants, and six deletion-insertions. Seven (33.3%) reversion deletions showed a microhomology length greater than 1 bp, suggesting microhomology-mediated end-join repair. Disease course data were obtained for all patients with reversion events: four patients acquired mutations after PARP-inhibitor treatment failure, two showed somatic reversion mutations after disease progression, following Pt-based treatment, five showed mutations after both treatments, one patient with pancreatic cancer and BRCA1 reversion mutations had no history of either treatment. Although reversion mutations commonly occur in BRCA-associated cancers, our findings suggest that reversion mutations due to Pt-chemotherapy might be correlated with BRCA1/2-mediated tumorigenesis even in non-BRCA-associated histologies.

Evaluation of the one-step nucleic acid amplification assay for detecting lymph node metastasis in patients with cervical and endometrial cancer: A multicenter prospective study.

OBJECTIVE: This multicenter study aimed to evaluate the accuracy of the one-step nucleic acid amplification (OSNA) assay in diagnosing lymph node metastasis (LNM) in patients with cervical and endometrial cancers. METHODS: Surgically removed LNs from patients with cervical and endometrial cancer were sectioned at 2-mm intervals along the short axis direction and alternately examined using the OSNA assay and conventional histopathological examination. Ultrastaging (200-µm LN sections) was performed for metastatic LNs using hematoxylin and eosin staining and immunostaining with an anti-CK19 antibody in cases where the OSNA assay and histopathological examination (performed using 2-mm LN sections) results showed discordance. RESULTS: A total of 437 LNs from 133 patients were included; 61 patients (14%) showed metastasis by histopathological examination, with a concordance rate of 0.979 (95% confidence interval [CI]: 0.961-0.991) with the OSNA assay. The sensitivity and specificity of the OSNA assay were 0.918 (95% CI: 0.819-0.973) and 0.989 (95% CI: 0.973-0.997), respectively. Discordance between the two methods was observed in nine LNs (2.1%), and allocation bias of metastatic foci was identified as the major cause of discordance. CONCLUSIONS: The OSNA assay showed equally accurate detection of LN metastasis as the histopathological examination. We suggest that the OSNA assay may be a useful tool for the rapid intraoperative diagnosis of LN metastasis in patients with cervical and endometrial cancers.

Long-Term Outcomes of Patients with Stroke Predicted by Clinicians to have no Chance of Meaningful Recovery: A Japanese Cohort Study.

BACKGROUND: Little is known about the natural history of comatose patients with brain injury, as in many countries most of these patients die in the context of withdrawal of life-sustaining therapies (WLSTs). The accuracy of predicting recovery that is used to guide goals-of-care decisions is uncertain. We examined long-term outcomes of patients with ischemic or hemorrhagic stroke predicted by experienced clinicians to have no chance of meaningful recovery in Japan, where WLST in patients with isolated neurological disease is uncommon. METHODS: We retrospectively reviewed the medical records of all patients admitted with acute ischemic stroke, intracerebral hemorrhage, or nontraumatic subarachnoid hemorrhage between January 2018 and December 2020 to a neurocritical care unit at Toda Medical Group Asaka Medical Center in Saitama, Japan. We screened for patients who were predicted by the attending physician on postinjury day 1-4 to have no chance of meaningful recovery. Primary outcome measures were disposition at hospital discharge and the ability to follow commands and functional outcomes measured by the Glasgow Outcome Scale-Extended (GOS-E), which was assessed 6 months after injury. RESULTS: From 860 screened patients, we identified 40 patients (14 with acute ischemic stroke, 19 with intracerebral hemorrhage, and 7 with subarachnoid hemorrhage) who were predicted to have no chance of meaningful recovery. Median age was 77 years (interquartile range 64-85), 53% (n = 21) were women, and 80% (n = 32) had no functional deficits prior to hospitalization. Six months after injury, 17 patients were dead, 14 lived in a long-term care hospital, 3 lived at home, 2 lived in a rehabilitation center, and 2 lived in a nursing home. Three patients reliably followed commands, two were in a vegetative state (GOS-E 2), four fully depended on others and required constant assistance (GOS-E 3), one could be left alone independently for 8 h per day but remained dependent (GOS-E 4), and one was independent and able to return to work-like activities (GOS-E 5). CONCLUSIONS: In the absence of WLST, almost half of the patients predicted shortly after the injury to have no chance of meaningful recovery were dead 6 months after the injury. A small minority of patients had good functional recovery, highlighting the need for more accurate neurological prognostication.

MEK inhibition suppresses metastatic progression of KRAS-mutated gastric cancer.

Metastatic progression of tumors is driven by genetic alterations and tumor-stroma interaction. To elucidate the mechanism underlying the oncogene-induced gastric tumor progression, we have developed an organoid-based model of gastric cancer from GAstric Neoplasia (GAN) mice, which express Wnt1 and the enzymes COX2 and microsomal prostaglandin E synthase 1 in the stomach. Both p53 knockout (GAN-p53KO) organoids and KRASG12V -expressing GAN-p53KO (GAN-KP) organoids were generated by genetic manipulation of GAN mouse-derived tumor (GAN wild-type [WT]) organoids. In contrast with GAN-WT and GAN-p53KO organoids, which manifested Wnt addiction, GAN-KP organoids showed a Wnt-independent phenotype and the ability to proliferate without formation of a Wnt-regulated three-dimensional epithelial architecture. After transplantation in syngeneic mouse stomach, GAN-p53KO cells formed only small tumors, whereas GAN-KP cells gave rise to invasive tumors associated with the development of hypoxia as well as to liver metastasis. Spatial transcriptomics analysis suggested that hypoxia signaling contributes to the metastatic progression of GAN-KP tumors. In particular, such analysis identified a cluster of stromal cells located at the tumor invasive front that expressed genes related to hypoxia signaling, angiogenesis, and cell migration. These cells were also positive for phosphorylated extracellular signal-regulated kinase (ERK), suggesting that mitogen-activated protein kinase (MAPK) signaling promotes development of both tumor and microenvironment. The MEK (MAPK kinase) inhibitor trametinib suppressed the development of GAN-KP gastric tumors, formation of a hypoxic microenvironment, tumor angiogenesis, and liver metastasis. Our findings therefore establish a rationale for application of trametinib to suppress metastatic progression of KRAS-mutated gastric cancer.

Retrospective evaluation of risk-reducing salpingo-oophorectomy for BRCA1/2 pathogenic variant carriers among a cohort study in a single institution.

BACKGROUND: Risk-reducing salpingo-oophorectomy is performed for the primary prevention of ovarian cancer in patients with hereditary breast-ovarian cancer syndrome. We performed risk-reducing salpingo-oophorectomy for the first time in Japan in 2008, and we experienced 20 cases of risk-reducing salpingo-oophorectomy through 2019. In the past, the use of risk-reducing salpingo-oophorectomy in Japan was restricted because it was not covered by a Japanese National Health Insurance. Since April 2020, risk-reducing salpingo-oophorectomy has been covered by insurance for patients with breast-ovarian cancer syndrome and pre-existing breast cancer, and this surgery is expected to become more widely implemented in Japan. METHODS: To contribute to the widespread use of risk-reducing salpingo-oophorectomy in the future, we retrospectively reviewed 20 cases of risk-reducing salpingo-oophorectomy at our hospital cohort study to clarify the issues in its implementation. RESULTS: The variant genes for which risk-reducing salpingo-oophorectomy was indicated were BRCA1 and BRCA2 in 13 (65%) and 7 patients (35%), respectively. The median age at which risk-reducing salpingo-oophorectomy was performed was 49 years (range, 38-58), 13 patients (65%) had gone through menopause, and 16 patients (80%) had a history of breast cancer. Of the five patients (25%) with vasomotor symptoms, four received Chinese medicine, and only one received hormone replacement therapy. Occult cancer was detected in the removed ovaries in two patients (10%), although no postoperative peritoneal carcinogenesis has been observed to date. CONCLUSIONS: Women who paid for risk-reducing salpingo-oophorectomy out of pocket were older than the recommended age at which the procedure should be performed, and this may explain the higher rate of occult cancers than previously reported. We need to perform risk-reducing salpingo-oophorectomy at the recommended age to ensure that the procedure is effective for primary prevention.

[Small B-cell neoplasm responding to ibrutinib after 17 years of cold agglutinin disease symptom].

In this study, we report a case of a 77-year-old woman who was presented with anemia in the winter of 2002. She was diagnosed with cold agglutinin disease (CAD) and treated with corticosteroids. Further, her hemoglobin levels were maintained between 7.0 g/dl and 8.0 g/dl. In May 2019, mature peripheral blood lymphocytes increased with exacerbation of hemolytic anemia. The lymphocytes were positive for CD19 and CD20, but negative for CD5, CD10, and CD23. Additionally, they were positive for cell surface IgM-κ. The B-cell neoplasm could not be further subclassified due to the lack of BCL2-IgH and BCL1-IgH rearrangement and morphology. The IgM-κ-type M-protein was found in serum, and the direct Coombs test was negative for IgG but positive for C3b/C3d. These findings suggested that small B-cell neoplasm-associated M-protein was involved in the development of CAD through complement activation. Based on the presence of TP53 deletion, the patient was treated with ibrutinib monotherapy. Although hemolysis rapidly improved with a dramatic decrease in lymphocytes, she died from a cerebral hemorrhage. It is assumed that ibrutinib improved CAD through suppression of small B-cell neoplasm-related M-protein. CAD can precede lymphoproliferative disorders; however, the risk of ibrutinib-associated hemorrhage should be noted.

Clinical utility of a self-administered questionnaire for assessment of hereditary gynecologic cancer.

BACKGROUND: A patient's medical history and familial cancer history are important information for assessing the risk of hereditary cancer. We have generated a self-administered questionnaire for patients with gynecologic cancer. This pilot study analyzed the usefulness of this questionnaire and the rates of patients that meet the Society of Gynecologic Oncology criteria in ovarian cancer and endometrial cancer patients. METHOD: Ovarian or endometrial cancer patients were recruited for this study. After informed consent was obtained, participants completed the questionnaire. Genetic risks were assessed from the data of each patient's questionnaire by Society of Gynecologic Oncology guideline. Clinical and pathological findings were compared between the genetic risk groups. RESULTS: A total of 105 patients were identified with ovarian cancer and 56 patients with endometrial cancer eligible for this study. According to the Society of Gynecologic Oncology guideline, of the 105 ovarian cancer patients, 25 patients (23%) had a 20-25% risk and three patients (2.9%) had a 5-10% risk of hereditary breast and ovarian cancer syndrome. A further 22 patients (21%) had a 5-10% risk of Lynch syndrome. Two patients (1.9%) met the Amsterdam criteria II. Of 56 endometrial cancer patients, 24 patients (42.9%) had a 5-10% risk of Lynch syndrome. The endometrial cancer patients with genetic risk of Lynch syndrome were younger (mean age: 47.79) at diagnosis compared to patients without a genetic risk of Lynch syndrome (mean age: 57.91). CONCLUSIONS: In this study, we were able to show that the newly designed questionnaire is a useful tool for evaluating cancer family history along with Society of Gynecologic Oncology criteria or Amsterdam criteria II. When considering the risk of Lynch syndrome for a patient with ovarian cancer, it is important to collect a second and third relative's family history.

Carcinoma of the lower uterine segment diagnosed with Lynch syndrome based on MSH6 germline mutation: A case report.

Endometrial cancer in the lower uterine segment (LUS) is associated with Lynch syndrome with MLH1 or MSH2 germline mutation. Here, we report a case of carcinoma of the LUS diagnosed with Lynch syndrome based on MSH6 germline mutation in a 46-year-old woman with abnormal vaginal bleeding. She had had rectal cancer at age 39 with a family history of colon cancer (father, 75 years), pancreatic cancer (paternal grandmother, 74 years), and colon cancer (maternal grandmother, 85 years). Magnetic resonance imaging showed a tumor in the LUS. Endometrial biopsy revealed endometrioid adenocarcinoma G1. As her cancer history met the revised Bethesda criteria, we examined microsatellite instability and the result was negative, but loss of the MSH6 expression was detected by immunohistochemistry. Genetic testing revealed deleterious germline mutation of MSH6, which was compatible with Lynch syndrome. To our knowledge, this is the first case of endometrial carcinoma of the LUS with MSH6 germline mutation.

Growth and sporulation defects in Bacillus subtilis mutants with a single rrn operon can be suppressed by amplification of the rrn operon.

The genome of Bacillus subtilis strain 168 encodes ten rRNA (rrn) operons. We previously reported that strains with only a single rrn operon had a decreased growth and sporulation frequency. We report here the isolation and characterization of suppressor mutants from seven strains that each have a single rrn operon (rrnO, A, J, I, E, D or B). The suppressor mutants for strain RIK656 with a single rrnO operon had a higher frequency of larger colonies. These suppressor mutants had not only increased growth rates, but also increased sporulation frequencies and ribosome levels compared to the parental mutant strain RIK656. Quantitative PCR analyses showed that all these suppressor mutants had an increased number of copies of the rrnO operon. Suppressor mutants were also isolated from the six other strains with single rrn operons (rrnA, J, I, E, D or B). Next generation and capillary sequencing showed that all of the suppressor mutants had tandem repeats of the chromosomal locus containing the remaining rrn operon (amplicon). These amplicons varied in size from approximately 9 to 179 kb. The amplifications were likely to be initiated by illegitimate recombination between non- or micro-homologous sequences, followed by unequal crossing-over during DNA replication. These results are consistent with our previous report that rrn operon copy number has a major role in cellular processes such as cell growth and sporulation.

Long G2 accumulates recombination intermediates and disturbs chromosome segregation at dysfunction telomere in Schizosaccharomyces pombe.

Protection of telomere (Pot1) is a single-stranded telomere binding protein which is essential for chromosome ends protection. Fission yeast Rqh1 is a member of RecQ helicases family which has essential roles in the maintenance of genomic stability and regulation of homologous recombination. Double mutant between fission yeast pot1Δ and rqh1 helicase dead (rqh1-hd) maintains telomere by homologous recombination. In pot1Δ rqh1-hd double mutant, recombination intermediates accumulate near telomere which disturb chromosome segregation and make cells sensitive to microtubule inhibitors thiabendazole (TBZ). Deletion of chk1(+) or mutation of its kinase domain shortens the G2 of pot1Δ rqh1-hd double mutant and suppresses both the accumulation of recombination intermediates and the TBZ sensitivity of that double mutant. In this study, we asked whether the long G2 is the reason for the TBZ sensitivity of pot1Δ rqh1-hd double mutant. We found that shortening the G2 of pot1Δ rqh1-hd double mutant by additional mutations of wee1 and mik1 or gain of function mutation of Cdc2 suppresses both the accumulation of recombination intermediates and the TBZ sensitivity of pot1Δ rqh1-hd double mutant. Our results suggest that long G2 of pot1Δ rqh1-hd double mutant may allow time for the accumulation of recombination intermediates which disturb chromosome segregation and make cells sensitive to TBZ.

Clinicopathologic analysis with immunohistochemistry for DNA mismatch repair protein expression in synchronous primary endometrial and ovarian cancers.

OBJECTIVE: Synchronous primary endometrial and ovarian cancers have been an important topic in clinical medicine because it is sometimes difficult to distinguish whether there are 2 primary tumors or a single primary tumor and an associated metastasis. In addition, although these tumors are recommended for either immunohistochemistry for DNA mismatch repair (MMR) proteins or a microsatellite instability test in the Bethesda guidelines as Lynch syndrome-associated cancers, few studies have completed these analyses. In this study, we characterized the clinicopathologic features and the expression pattern of MMR proteins in synchronous primary endometrial and ovarian cancers. METHODS: Clinicopathologic features and the expression pattern of MMR proteins (MLH1, MSH2, and MSH6) were characterized and analyzed in 32 synchronous primary endometrial and ovarian cancers. RESULTS: Most synchronous cancers are endometrioid type (endometrioid/endometrioid) (n = 24, 75%), grade 1 (n = 19, 59.4%), and diagnosed as stage I (n = 15, 46.9%) in both endometrium and ovary. It is worth mentioning that 75% of the patients (n = 24) had endometriosis, which was more common (n = 21, 87.5%) in endometrioid/endometrioid cancers, whereas only 3 cases (37.5%) were of different histology (P = 0.018). Loss of expression of at least 1 MMR protein was observed in 17 (53.1%) of the endometrial tumors and in 10 (31.3%) of ovarian tumors. Only 4 cases (12.5%) that had specific MMR protein loss showed the same type of loss for both endometrial and ovarian tumors, in which 3 of the cases were losses in MLH1. One case showed concordant MSH6 protein loss, although the cases did not meet the Amsterdam criteria II. CONCLUSIONS: These results suggest that most synchronous primary endometrial ovarian cancers are not hereditary cancers caused by germ line mutations but rather sporadic cancers.

Enhanced dipicolinic acid production during the stationary phase in Bacillus subtilis by blocking acetoin synthesis.

Bacterial bio-production during the stationary phase is expected to lead to a high target yield because the cells do not consume the substrate for growth. Bacillus subtilis is widely used for bio-production, but little is known about the metabolism during the stationary phase. In this study, we focused on the dipicolinic acid (DPA) production by B. subtilis and investigated the metabolism. We found that DPA production competes with acetoin synthesis and that acetoin synthesis genes (alsSD) deletion increases DPA productivity by 1.4-fold. The mutant showed interesting features where the glucose uptake was inhibited, whereas the cell density increased by approximately 50%, resulting in similar volumetric glucose consumption to that of the parental strain. The metabolic profiles revealed accumulation of pyruvate, acetyl-CoA, and the TCA cycle intermediates in the alsSD mutant. Our results indicate that alsSD-deleted B. subtilis has potential as an effective host for stationary-phase production of compounds synthesized from these intermediates.

Drug repositioning for gynecologic tumors: a new therapeutic strategy for cancer.

The goals of drug repositioning are to find a new pharmacological effect of a drug for which human safety and pharmacokinetics are established and to expand the therapeutic range of the drug to another disease. Such drug discovery can be performed at low cost and in the short term based on the results of previous clinical trials. New drugs for gynecologic tumors may be found by drug repositioning. For example, PPAR ligands may be effective against ovarian cancer, since PPAR activation eliminates COX-2 expression, arrests the cell cycle, and induces apoptosis. Metformin, an antidiabetic drug, is effective for endometrial cancer through inhibition of the PI3K-Akt-mTOR pathway by activating LKB1-AMPK and reduction of insulin and insulin-like growth factor-1 due to AMPK activation. COX-2 inhibitors for cervical cancer may also be examples of drug repositioning. PGE2 is induced in the arachidonate cascade by COX-2. PGE2 maintains high expression of COX-2 and induces angiogenic factors including VEGF and bFGF, causing carcinogenesis. COX-2 inhibitors suppress these actions and inhibit carcinogenesis. Combination therapy using drugs found by drug repositioning and current anticancer drugs may increase efficacy and reduce adverse drug reactions. Thus, drug repositioning may become a key approach for gynecologic cancer in drug discovery.

Tetracycline tolerance mediated by gene amplification in Bacillus subtilis.

Bacillus subtilis can acquire a higher tolerance to tetracycline by increasing the gene dosage of its resistance gene tetB. In this study, we estimated the multiplication effect of tetB on tetracycline tolerance. Cells harbouring multiple copies of tetB were found to comprise approximately 30 % of the total tetracycline-resistant cell population when selected on medium containing 10 µg tetracycline ml(-1). Disruption of recA resulted in a significant decrease in the frequency of tetB amplification. Although four direct repeats exist around tetB, the majority of tetB amplicons were found to be flanked by non-homologous sequences, indicating that the initial duplication of tetB can occur largely through RecA-independent recombination. The correlation between the tetB copy number and the MIC values for tetracycline indicated that more than three copies of tetB were required for tolerance to 10 µg tetracycline ml(-1). Thus, the RecA-dependent expansion step appears to be necessary for developing significant tetracycline tolerance mediated by tetB amplification.

A tumor of the uterine cervix with a complex histology in a Peutz-Jeghers syndrome patient with genomic deletion of the STK11 exon 1 region.

Patients with Peutz-Jeghers syndrome (PJS) have a risk of complicating malignant tumors, including cancer of the uterine cervix. Mutations in the STK11 gene have been identified as being responsible for PJS. However, the genotype-phenotype correlation in PJS is poorly understood, especially with respect to malignant tumors. Here, we report a detailed analysis of a case of a cervical tumor in a PJS patient showing a large genomic deletion in exon 1 of STK11 without human papillomavirus infection. Histological examination revealed a complex histology consisting of three components: lobular endocervical gland hyperplasia (LEGH), minimal deviation adenocarcinoma (MDA) and mucinous adenocarcinoma. Immunohistochemistry for STK11 was positive in the LEGH and MDA components, while that of the mucinous adenocarcinoma stained very faintly. These findings support a close relationship among LEGH, MDA and mucinous adenocarcinoma and imply that inactivation of STK11 may occur during progression from MDA to mucinous adenocarcinoma.

Family history and BRCA1/BRCA2 status among Japanese ovarian cancer patients and occult cancer in a BRCA1 mutant case.

BACKGROUND: This study aimed to examine family history among Japanese ovarian cancer patients and to investigate the TP53 status of fallopian tube epithelial and ovarian cancer cells in a Japanese BRCA1 mutant case that may be associated with the transformed state in hereditary ovarian cancer. METHODS: One hundred and two primary ovarian cancer patients were retrospectively evaluated in this cross-sectional study. The family history of cancer was determined in probands. In a BRCA1 mutant case, p53 immunostaining and direct sequencing, followed by laser-capture microdissection, were performed for the fallopian tube, considered the origin of ovarian cancer. RESULTS: Nine of 102 (8.8%) families were regarded as having hereditary breast-ovarian cancer syndrome, two families (2.0%) were diagnosed with Lynch syndrome and six patients harbored BRCA1 or BRCA2 mutations. One case underwent risk-reductive salpingo-oophorectomy as a BRCA1 mutant carrier was retrospectively diagnosed as occult cancer. Common TP53 mutations were detected in cancer and fallopian tube epithelial cells in the case. CONCLUSIONS: Here, we integrate family cancer history and histology in ovarian cancer cases as well as TP53 status in a BRCA1 mutant case into a discussion regarding carcinogenesis in a Japanese population. The TP53 status for the BRCA1 mutant case examined here supports the recently proposed theory that ovarian cancer develops because of BRCA1 or BRCA2 inactivation and/or TP53 mutations.

Carcinogenic mechanisms of endometrial cancer: involvement of genetics and epigenetics.

Endometrial cancer is increasing worldwide and the number of patients with this disease is likely to continue to grow, including younger patients. Many endometrial cancers show estrogen-dependent proliferation, but the carcinogenic mechanisms are unknown or not completely explained beyond mutations of single oncogenes and tumor suppressor genes. Possible carcinogenic mechanisms include imbalance between endometrial proliferation by unopposed estrogen and the mismatch repair (MMR) system; hypermethylation of the MMR gene hMLH1; mutation of PTEN, ß-catenin and K-ras genes in type I endometrial cancer and of HER-2/neu and p53 genes in type II endometrial cancer; hypermethylation of SPRY2, RASSF1A, RSK4, CHFR and CDH1; and methylation of tumor suppressor microRNAs, including miR-124, miR-126, miR-137, miR-491, miR-129-2 and miR-152. Thus, it is likely that the carcinogenic mechanisms of endometrial cancer involve both genetic and epigenetic changes. Mutations and methylation of MMR genes induce various oncogenic changes that cause carcinogenesis, and both MMR mutation in germ cells and methylation patterns may be inherited over generations and cause familial tumorigenesis. Determination of the detailed carcinogenic mechanisms will be useful for prevention and diagnosis of endometrial cancer, risk assessment, and development of new treatment strategies targeting MMR genes.

[Evaluation of Analytical Performance of HISCL TM, a Chemiluminescent Enzyme Immunoassay and the Use of Thrombomodulin as a Marker for Endothelial Dysfunction].

Thrombomodulin (TM) is an endothelial receptor for thrombin. The thrombin-thrombomodulin complex activates protein C in the anticoagulant pathway. Soluble TM is thought to be a marker for endothelial cell damage. We have evaluated the analytical performance of the HISCL TM test, a chemiluminescent enzyme immunoassay that measures soluble TM using biotinylated thrombomodulin monoclonal antibodies on Sysmex HISCL-2000i analyzer. Within-run coefficient of variation (CV) for control samples with low and high TM levels were 1.67% and 1.95% whereas between-run CVs for the control samples were 2.18% and 3.25% respectively. The assay showed excellent dilution linearity up to a TM level of 198 TU/mL with the lower limit of detection of 0.34 TU/mL. There was no effect of interfering substances on TM measurements. Results obtained on 362 patients showed that for those patients with a high TM level, C-reactive protein (CRP), fibrinogen (FIB), D-dimer, thrombin-antithrombin complex (TAT) and plasmin-α2 plasmin inhibitor complex (PIC) levels were significantly higher than in those patients with a normal TM level, and glomerular filtration rates (eGFR) were significantly lower than in those patients with a normal TM level. It was also observed that patients with high TM levels have significantly higher levels of von Willebrand factor antigen (vWFAg) and ristocetin cofactor activity (vWFRCo) which are associated with marked endothelial dysfunction. This study demonstrates that the HISCL TM test fulfils the analytical performance requirements for routine laboratory testing and an increased TM level detected is a useful indicator of endothelial dysfunction.

The APC/C activator Cdh1 regulates the G2/M transition during differentiation of placental trophoblast stem cells.

Differentiation of placental trophoblast stem (TS) cells to trophoblast giant (TG) cells is accompanied by transition from a mitotic cell cycle to an endocycle. Here, we report that Cdh1, a regulator of the anaphase-promoting complex/cyclosome (APC/C), negatively regulates mitotic entry upon the mitotic/endocycle transition. TS cells derived from homozygous Cdh1 gene-trapped (Cdh1(GT/GT)) murine embryos accumulated mitotic cyclins and precociously entered mitosis after induction of TS cell differentiation, indicating that Cdh1 is required for the switch from mitosis to the endocycle. Furthermore, the Cdh1(GT/GT) TS cells and placenta showed aberrant expression of placental differentiation markers. These data highlight an important role of Cdh1 in the G2/M transition during placental differentiation.

Multiple rRNA operons are essential for efficient cell growth and sporulation as well as outgrowth in Bacillus subtilis.

The number of copies of rRNA (rrn) operons in a bacterial genome differs greatly among bacterial species. Here we examined the phenotypic effects of variations in the number of copies of rRNA genes in the genome of Bacillus subtilis by analysis of eight mutant strains constructed to carry from two to nine copies of the rrn operon. We found that a decrease in the number of copies from ten to one increased the doubling time, and decreased the sporulation frequency and motility. The maximum levels for transformation activity were similar among the strains, although the competence development was significantly delayed in the strain with a single rrn operon. Normal sporulation only occurred if more than four copies of the rrn operon were present, although ten copies were needed for vegetative growth after germination of the spores. This behaviour was seen even though the intracellular level of ribosomes was similar among strains with four to ten copies of the rrn operon. Furthermore, ten copies of the rrn operon were needed for the highest swarming activity. We also constructed 21 strains that carried all possible combinations of two copies of the rrn operons, and found that these showed a range of growth rates and sporulation frequencies that all fell between those recorded for strains with one or three copies of the rrn operon. The results suggested that the copy number of the rrn operon has a major influence on cellular processes such as growth rate and sporulation frequency.