BRZ-INSENSITIVE-PALE GREEN 1 is encoded by chlorophyll biosynthesis enzyme gene that functions in the downstream of brassinosteroid signaling.

Brassinosteroids (BRs), a kind of phytohormone, have various biological activities such as promoting plant growth, increasing stress resistance, and chloroplast development. Though BRs have been known to have physiological effects on chloroplast, the detailed mechanism of chloroplast development and chlorophyll biosynthesis in BR signaling remains unknown. Here we identified a recessive pale green Arabidopsis mutant, Brz-insensitive-pale green1 (bpg1), which was insensitive to promoting of greening by BR biosynthesis-specific inhibitor Brz in the light. BPG1 gene encoded chlorophyll biosynthesis enzyme, 3, 8-divinyl protochlorophyllide a 8-vinyl reductase (DVR), and bpg1 accumulated divinyl chlorophylls. Chloroplast development was suppressed in bpg1. Brz dramatically increased the expression of chlorophyll biosynthesis enzyme genes, including BPG1. These results suggest that chlorophyll biosynthesis enzymes are regulated by BR signaling in the aspect of gene expression and BPG1 plays an important role in regulating chloroplast development.

Urinary organic acids spectra in children with altered gut microbiota composition and autistic spectrum disorder.

Introduction: Alteration of human gut microbiota is described in a number of neuro-developmental and cognitive disorders including autistic spectrum disorder (ASD). Along with the changes in the gut microbiota, children with ASD are also reported to have changes in urinary organic acid spectra implying these metabolites as potential biomarkers for gastrointestinal dysbiosis.Aim: Identify urinary metabolites that would indicate specific changes in the gut microbiota and could be useful as biomarkers.Methods: The study group consisted of 44 children with ASD. Urinary organic acids spectra and composition of gut microbiota were analysed.Results: Any significant deviation in quantified metabolites compared to the reference values were not confirmed. The main variations were detected in concentration of p-cresol and 3-(3-hydroxyphenyl)-3-hydroxypropionic acid (HPHPA), but we cannot confirm the presence of HPHPA in urine as a biomarker for Clostridium sp. overgrowth in the gut. The acquired results indicate higher relative abundance of Firmicutes phylum alone may be attributed to increased concentration of p-cresol in urine. Decreased Bacteroidetes/Firmicutes ratio was found in the group with the presence of HPHPA in urine.Conclusions: Metabolites of human urine can be used as biomarkers for alterations of gut microbiota with caution, guided treatment should be administrated only based on gut microbiota analysis results or in combination with urinary organic acid results, but not solely based on organic acid biomarkers.

An Effect of Culture Media on Epithelial Differentiation Markers in Breast Cancer Cell Lines MCF7, MDA-MB-436 and SkBr3.

Background and objectives: Cell culture is one of the mainstays in the research of breast cancer biology, although the extent to which this approach allows to preserve the original characteristics of originating tumor and implications of cell culture findings to real life situations have been widely debated in the literature. The aim of this study was to determine the role of three cell culture media on transcriptional expression of breast cancer markers in three breast cancer reference cell lines (MCF7, SkBr3 and MDA-MB-436). Materials and methods: Cell lines were conditioned in three studied media (all containing 5% fetal bovine serum (FBS) + hormones/growth factors; different composition of basal media) for four passages. Population growth was characterized by cumulative population doubling levels, average generation time, cell yield and viability at the fourth passage. Transcriptional expression of breast cancer differentiation markers and regulatory transcriptional programs was measured by qPCR. Results: Differences in the composition of growth media significantly influenced the growth of studied cell lines and the expression of mammary lineage governing transcriptional programs and luminal/basal markers. Effects of media on transcriptional expression were more pronounced in luminal cell lines (MCF7, SkBr3), than in the basal cell line (MDA-MB-436). Changes in growth media in terms of supplementation and basal medium delayed growth of cells, but improved cell yields. Conclusions: The expression of breast cancer cell differentiation phenotypic markers depends on the composition of cell growth medium, therefore cell culture as a tool in phenotypic studies should be used considering this effect. The findings of such studies should always be interpreted with caution. The formulation of cell growth media has greater effect on the expression of phenotypic markers in luminal, rather than basal cell lines. Media containing mitogens and higher vitamin content improved efficacy of cell culture in terms of cell yields, although greatly increased growth times.

High expression of miR-214 is associated with a worse disease-specific survival of the triple-negative breast cancer patients.

BACKGROUND: Hereditary triple-negative breast cancer patients have better recurrence-free survival than triple-negative sporadic ones. High expression of some of the miRNAs is related to worse overall and disease-free survival of triple-negative breast cancer patients. The attempt to associate expression level of some miRNA in triple-negative hereditary and sporadic breast cancers to disease specific survival was performed in this study. MATERIAL AND METHODS: Study group was made of 18 triple-negative breast cancer patients harboring the BRCA1 gene mutations and 32 triple-negative sporadic breast cancer patients. Quantitative amount of mir-10b, mir-21, mir-29a, mir-31, and mir-214 by real-time PCR was assessed. The disease-specific survival in relation of high and low levels of some of the miRNAs was analyzed using Log-rank (Mantel-Cox) test. RESULTS: MiR-214 showed significantly higher expression level in sporadic tissues than in hereditary ones (p = 0.0005). Triple-negative breast cancer patients with high level of miR-214 showed significantly worse disease-specific survival than patients with low level (p = 0.0314). CONCLUSIONS: Our finding suggests that miR-214 possibly could be used as a potential prognostic biomarker for triple-negative breast cancer patients.

BRCA1/2 mutation screening in high-risk breast/ovarian cancer families and sporadic cancer patient surveilling for hidden high-risk families.

BACKGROUND: The estimated ratio of hereditary breast/ovarian cancer (HBOC) based on family history is 1.5% in Latvia. This is significantly lower than the European average of 5-10%. Molecular markers like mutations and SNPs can help distinguish HBOC patients in the sporadic breast and ovarian cancer group. METHODS: 50 patients diagnosed with HBOC in the Latvian Cancer Registry from January 2005 to December 2008 were screened for BRCA1 founder mutation-negatives and subjected to targeted resequencing of BRCA1 and BRCA2 genes. The newly found mutations were screened for in the breast and ovarian cancer group of 1075 patients by Real Time-PCR/HRM analysis and RFLP. RESULTS: Four BRCA2 mutations including three novel BRCA2 frameshift mutations and one previously known BRCA2 frameshift mutation and one BRCA1 splicing mutation were identified. Two of the BRCA2 mutations were found in a group of consecutive breast cancer patients with a frequency of 0.51% and 0.38%. CONCLUSIONS: Molecular screening of sequential cancer patients is an important tool to identify HBOC families.

Correction: Effectiveness of Secondary Risk-Reducing Strategies in Patients With Unilateral Breast Cancer With Pathogenic Variants of BRCA1 and BRCA2 Subjected to Breast-Conserving Surgery: Evidence-Based Simulation Study.

[This corrects the article DOI: .].

Effectiveness of Secondary Risk-Reducing Strategies in Patients With Unilateral Breast Cancer With Pathogenic Variants of BRCA1 and BRCA2 Subjected to Breast-Conserving Surgery: Evidence-Based Simulation Study.

BACKGROUND: Approximately 62% of patients with breast cancer with a pathogenic variant (BRCA1 or BRCA2) undergo primary breast-conserving therapy. OBJECTIVE: The study aims to develop a personalized risk management decision support tool for carriers of a pathogenic variant (BRCA1 or BRCA2) who underwent breast-conserving therapy for unilateral early-stage breast cancer. METHODS: We developed a Bayesian network model of a hypothetical cohort of carriers of BRCA1 or BRCA2 diagnosed with stage I/II unilateral breast cancer and treated with breast-conserving treatment who underwent subsequent second primary cancer risk-reducing strategies. Using event dependencies structured according to expert knowledge and conditional probabilities obtained from published evidence, we predicted the 40-year overall survival rate of different risk-reducing strategies for 144 cohorts of women defined by the type of pathogenic variants (BRCA1 or BRCA2), age at primary breast cancer diagnosis, breast cancer subtype, stage of primary breast cancer, and presence or absence of adjuvant chemotherapy. RESULTS: Absence of adjuvant chemotherapy was the most powerful factor that was linked to a dramatic decline in survival. There was a negligible decline in the mortality in patients with triple-negative breast cancer, who received no chemotherapy and underwent any secondary risk-reducing strategy, compared with surveillance. The potential survival benefit from any risk-reducing strategy was more modest in patients with triple-negative breast cancer who received chemotherapy compared with patients with luminal breast cancer. However, most patients with triple-negative breast cancer in stage I benefited from bilateral risk-reducing mastectomy and risk-reducing salpingo-oophorectomy or just risk-reducing salpingo-oophorectomy. Most patients with luminal stage I/II unilateral breast cancer benefited from bilateral risk-reducing mastectomy and risk-reducing salpingo-oophorectomy. The impact of risk-reducing salpingo-oophorectomy in patients with luminal breast cancer in stage I/II increased with age. Most older patients with the BRCA1 and BRCA2 pathogenic variants in exons 12-24/25 with luminal breast cancer may gain a similar survival benefit from other risk-reducing strategies or surveillance. CONCLUSIONS: Our study showed that it is mandatory to consider the complex interplay between the types of BRCA1 and BRCA2 pathogenic variants, age at primary breast cancer diagnosis, breast cancer subtype and stage, and received systemic treatment. As no prospective study results are available at the moment, our simulation model, which will integrate a decision support system in the near future, could facilitate the conversation between the health care provider and patient and help to weigh all the options for risk-reducing strategies leading to a more balanced decision.

Bladder cancer trends in Latvia during 1990-2017: incidence, mortality, and survival rates.

INTRODUCTION: The aim of this article was to evaluate bladder cancer (BC) incidence, mortality and survival trends in Latvia over the past 28 years. MATERIAL AND METHODS: Our study included patients diagnosed with BC between 1990 and 2017. The data were obtained from the national population-based cancer registry. Joinpoint regression analysis was used to identify points where a significant change in incidence and mortality trends occurred, accordingly with the patient's gender and age. Relative survival (RS) was estimated by Ederer I and II methods. RESULTS: Altogether, 9589 patients with initial BC diagnosis were included in the study. The age-standardised (ASR) incidence rates (per 100,000) increased from 6.8 in 1990 to 12.5 in 2014 followed by a statistically insignificant decrease continuing up to 2017. The ASR BC mortality rates (per 100,000) also rose from 3.9 in 1990 to 4.4 in 2017. However, there was a decline in BC mortality trends in the age-group 40-59 with annual percentage change (APC) -1.1%. RS rates increased from 55.0 % in 1990-2000 to 59.0% in years 2013-2017. CONCLUSIONS: This study revealed that the incidence and mortality rates have been gradually increasing over the past 28 years. The exception being cancer-specific mortality in the age group 40-59, which tends to decrease. Although the 5-year RS rates improved over the reviewed period, there is still plenty of room for improvement.

Chromothripsis and progression-free survival in metastatic colorectal cancer.

Metastatic dissemination of the primary tumor is the major cause of death in colorectal cancer (CRC) patients. Multiple chromosomal breaks and chromothripsis, a phenomenon involving multiple chromosomal fragmentations occurring in a single catastrophic event, are associated with cancer genesis, progression and developing of metastases. The aim of this study was to evaluate the effect of chromothripsis and total breakpoint count (breakpoint instability index) on progression-free survival (PFS). A total of 19 patients with metastatic CRC (mCRC) receiving FOLFOX first-line palliative chemotherapy between August, 2011 and October, 2012 were selected for this study. The results indicated that the highest breakpoint count was observed in chromosomes 1, 2 and 6. Chromothripsis was detected in 52.6% of the study patients. Furthermore, chromothripsis was associated with an increased median PFS (mPFS; 14 vs. 8 months, respectively; P=0.03), but an association with overall survival was not identified. The present study demonstrated that chromothripsis affected CRC patient survival, suggesting a role for this event as a prognostic and predictive marker in mCRC treatment.

Prognostic role of BRCA1 mutation in patients with triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is proposed to be an immunohistochemical surrogate of the basal-like breast cancer subtype. In spite of the relative chemosensitivity of this cancer subtype, it is characterized by aggressive clinical behavior; therefore, a further subclassification of TNBC is required to develop new targeted treatment. In previous studies, a strong correlation between BRCA1 mutation-associated tumors and TNBC has been identified. The aim of the present study was to investigate the prognostic significance of carrying two germline BRCA1 founder mutations (4153delA and 5382insC) in patients with TNBC in the Latvian population. A total of 78 consecutive BRCA1 mutation-negative and 38 BRCA1 mutation-positive invasive TNBC patients in stage I-IV with no history of ovarian or other primary advanced cancers, who had undergone definitive surgery and genetic testing between 2005 and 2011, were deemed eligible for study. Relapse rates and breast cancer-specific survival (BCS) outcomes were compared between mutation carriers and non-carriers. Univariate and multivariate analyses Cox proportional-hazards models were used to compute independent predictors of survival outcomes. No statistically significant differences were identified in relation to tumor size, T stage, stage, Ki-67 status and tumor differentiation grade between the two groups. The median follow-up period was 36 months for mutation carriers and 41 months for non-carriers. A higher proportion of BRCA1 mutation non-carriers experienced distant recurrence compared with that of mutation carriers (P<0.03). BRCA1 mutation carriers had a significantly higher BCS than non-carriers (94.9 vs. 76.9%; P<0.02). In the univariate analyses, BRCA1-positive status was associated with decreased risk of distant recurrence (HR, 0.228; 95% Cl, 0.052-0.997; P<0.049) and breast cancer-specific mortality (HR, 0.209; 95% Cl, 0.048-0.902; P<0.036). In the multivariate analysis Cox proportional-hazards model, BRCA1-positive status was an independent favorable prognostic factor for distant recurrence-free survival (HR, 3.301; 95% Cl, 1.102-9.893; P<0.033). In conclusion, results of the present study demonstrate that positive BRCA1 founder mutation status in TNBC, with no evidence of ovarian or other cancer type in advanced stage, significantly improves prognosis.