Aberrant DNA methylation of imprinted loci in superovulated oocytes

BACKGROUND: There is an increased incidence of rare imprinting disorders associated with assisted reproduction technologies (ARTs). The sex-specific epigenetic modifications that are imposed during gametogenesis act as a primary imprint to distinguish maternal and paternal alleles. The most likely candidate for the gametic mark is DNA methylation. However, the timing of DNA methylation acquisition in adult oocytogenesis and the effects of superovulation are unknown. METHODS: We examined the maternal methylation of PEG1(MEST), LIT1(KCNQ1OT1) and ZAC(PLAGL1) and the paternal methylation of H19 in adult growing oocytes of humans and mice and compared them with the methylation status of mouse neonatal growing oocytes by using bisulphite sequencing. Furthermore, we examined the effects of superovulation in the human and mouse. RESULTS: Maternal methylation of these genes has already been initiated to some extent in adult human and mouse non-growing oocytes but not in mouse neonates. In addition, the methylation dynamics during adult human and mouse oocyte development changed more gradually than those during neonatal oocyte development. Furthermore, we found the demethylation of PEG1 in growing oocytes from some ART-treated infertile women and a gain in the methylation of H19. We also detected methylation changes in superovulated mice. CONCLUSION: Our studies in the human and mouse suggest that superovulation can lead to the production of oocytes without their correct primary imprint and highlight the need for more research into ARTs.     

Gender differences in prognosis after esophagectomy for esophageal cancer

Purpose

The purpose of this study was to clarify the gender differences in the prognosis, as well as mortality and morbidity, of patients who have undergone esophagectomy for esophageal cancer.

Methods

The clinical results of esophagectomy were compared between 975 male and 156 female patients with esophageal cancer.

Results

The male to female ratios of cervical and thoracic esophageal cancer were 1.87 and 7.38, respectively (P < 0.01). The incidence of preoperative comorbidities was 32.4 and 17.4 %, respectively, and the rates of both tobacco and alcohol abuse were significantly lower in the females than in the males. The mortality rate was lower in the females (3.8 %) than in the males (5.7 %), although the differences were not significant. The overall survival was significantly better in the female than in the male patients (P = 0.039). The 5- and 10-year overall survival rates were 32.6 and 20.5 % in the males and 39.5 and 32.5 % in the females, respectively. A multivariate analysis revealed gender to be an independent prognostic factor. However, no significant differences were recognized in disease-specific survival.

Conclusions

These results suggest that the prognosis of females with esophageal cancer is better than that of males after esophagectomy, most likely due to multiple clinical factors, such as a more favorable lifestyle and general status.     

Right bundle branch block without overt heart disease predicts higher risk of pacemaker implantation: The study of atomic-bomb survivors

Background

We investigated the clinical course of complete right bundle branch block (RBBB) or RBBB with axis deviation (AD) in terms of subsequent pacemaker implantation for high-degree atrioventricular (AV) block or sick sinus syndrome (SSS).

Methods and results

Among the 16,170 atomic-bomb survivors in our biennial health examination between July 1967 and December 2010, we detected 520 newly-acquired RBBB subjects with no organic heart disease, and selected 1038 age- (at RBBB diagnosis) and sex-matched subjects without RBBB to serve as comparison subjects. Multivariate Cox regression analysis was used to estimate the hazard ratios (HRs) for the risk of pacemaker implantation due to all causes, AV block or SSS between RBBB and comparison subjects and between RBBB subjects with and without AD. The risk of pacemaker implantation for RBBB was 4.79 (95% confidence interval [CI] 1.89–12.58; P = 0.001), 3.77 (95% CI, 1.09–13.07; P = 0.036), and 6.28 (95% CI, 1.24–31.73, P = 0.026) when implantation was for all causes, AV block and SSS, respectively. RBBB subjects with AD had a higher risk for all-cause pacemaker implantation than subjects without AD (HR, 3.03; 95% CI, 1.00–9.13, P = 0.049). RBBB subjects with AD were younger than subjects without AD at the time of RBBB diagnosis (59.4 ± 7.6 vs 74.4 ± 3.1 years old, P = 0.019), and their progression from diagnosis to pacemaker implantation took longer (15.1 ± 6.6 vs 6.4 ± 3.0 years, P = 0.032).

Conclusions

RBBB, especially with AD, progresses to AV block and SSS that requires pacemaker implantation; the mechanisms by which the conduction defect progresses differ among patients with and without AD.     

Frank's sign with acute aortic dissection

A 59‐year‐old man with a long smoking history presented with sudden back pain. Frank''s sign was noticed in his bilateral ears, and computed tomography revealed Stanford type A acute aortic dissection. If young patients have Frank''s sign, attention should be paid to aortic disease in addition to coronary artery disease.     

GET4 is a novel driver gene in colorectal cancer that regulates the localization of BAG6, a nucleocytoplasmic shuttling protein

Colorectal cancer (CRC) is one of the most common types of cancer and a significant cause of cancer mortality worldwide. Further improvements of CRC therapeutic approaches are needed. BCL2‐associated athanogene 6 (BAG6), a multifunctional scaffold protein, plays an important role in tumor progression. However, regulation of BAG6 in malignancies remains unclear. This study showed that guided entry of tail‐anchored proteins factor 4 (GET4), a component of the BAG6 complex, regulates the intercellular localization of BAG6 in CRC. Furthermore, GET4 was identified as a candidate driver gene on the short arm of chromosome 7, which is often amplified in CRC, by our bioinformatics approach using the CRC dataset from The Cancer Genome Atlas. Clinicopathologic and prognostic analyses using CRC datasets showed that GET4 was overexpressed in tumor cells due to an increased DNA copy number. High GET4 expression was an independent poor prognostic factor in CRC, whereas BAG6 was mainly overexpressed in the cytoplasm of tumor cells without gene alteration. The biological significance of GET4 was examined using GET4 KO CRC cells generated with CRISPR‐Cas9 technology or transfected CRC cells. In vitro and in vivo analyses showed that GET4 promoted tumor growth. It appears to facilitate cell cycle progression by cytoplasmic enrichment of BAG6‐mediated p53 acetylation followed by reduced p21 expression. In conclusion, we showed that GET4 is a novel driver gene and a prognostic biomarker that promotes CRC progression by inducing the cytoplasmic transport of BAG6. GET4 could be a promising therapeutic molecular target in CRC.     

Epidermal growth factor receptor (EGFR)—tyrosine kinase inhibitors as a first-line treatment for postoperative recurrent and EGFR-mutated non-small-cell lung cancer

 Open in a separate windowOBJECTIVESTo clarify survival outcomes and prognostic factors of patients receiving epidermal growth factor receptor (EGFR) - tyrosine kinase inhibitors (TKIs) as first-line treatment for postoperative recurrence.METHODSA retrospective chart review was performed to identify consecutive patients who received EGFR-TKIs as first-line treatment for postoperative recurrence of non-small-cell lung cancer (NSCLC) harbouring EGFR gene mutations at our institution between August 2002 and October 2020. Therapeutic response, adverse events, progression-free survival (PFS) and overall survival (OS) were investigated. Survival outcomes were assessed using the Kaplan–Meier analysis. The Cox proportional hazards model was used for univariable and multivariable analyses.RESULTSSixty-four patients were included in the study. The objective response and disease control rates were 53% and 92%, respectively. Grade 3 or greater adverse events were noted in 4 (6.3%) patients, including 1 patient (1.6%) of interstitial pneumonia. The median follow-up period was 28.5 months (range 3–202 months). The total number of events was 43 for PFS and 23 for OS, respectively. The median PFS was 18 months, and the median OS was 61 months after EGFR-TKI treatment. In multivariable analysis, osimertinib showed a tendency to prolong PFS [hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.12–1.1; P = 0.071], whereas the micropapillary component was significantly associated with shorter OS (HR 2.1, 95% CI 1.02–6.9; P = 0.045).CONCLUSIONSEGFR-TKIs as first-line treatment appeared to be a reasonable treatment option in selected patients with postoperative recurrent EGFR-mutated NSCLC. Osimertinib and the micropapillary component may be prognostic factors.     

Peptide vaccination for patients with melanoma and other types of cancer based on pre-existing peptide-specific ctotoxic T-lymphocyte precursors in the periphery

Identification of antigenic peptides expressed on cancer cells enables us to treat cancer patients with peptide-based immunotherapy. Although optimal protocols for peptide-based vaccines have not yet been elucidated, boosting the immune system could be a better approach than priming the immune system to elicit prompt and potent peptide-specific T-cell responses in cancer patients. With this possibility in mind, the authors undertook a clinical trial in which cancer patients were vaccinated with peptides (maximum 4) after confirmation of pre-existing peptide-specific cytotoxic T-lymphocyte (CTL) precursors in the periphery. Fourteen patients (seven with melanoma and seven with other types of cancer) positive for either HLA-A24 or HLA-A2 were enrolled in this study. Fourteen and 16 peptides were used to screen for HLA-A24+ and HLA-A2+ patients, respectively. The vaccination was well tolerated, and the only adverse effects were local pain and fever. Kinetic analysis revealed that peptide-reactive CTLs increased after peptide vaccination in 7 of 14 patients. Immunoglobulin G (IgG) reactive to the administered peptides was detected in 2 patients before vaccination, although it became detectable in 8 of the other 12 patients after the peptide vaccination. Stable disease for more than 6 months was observed in five patients (one with melanoma and four with other types of cancer); all of these patients showed increased levels of peptide-specific IgG. These results indicate that peptide vaccination of patients showing evidence of pre-existing peptide-specific CTL precursors can be applied in further clinical trials aimed at the treatment of melanoma and other types of cancer.     

Efficacy of Breast Conservation Therapy in Early Stage Bilateral Breast Cancer

The purpose of this study was to evaluate the outcome of patients with bilateral breast cancer as compared to unilateral breast cancer treated with breast conservation therapy. Sixty patients with bilateral breast cancer (BBC) and 1,080 unilateral breast cancer (UBC) patients treated with breast conservation therapy from 1977 to 1994 were analyzed for outcome. Of the 60 bilateral patients, 44 were metachronous bilateral breast cancer patients (MBBC) and 16 were synchronous bilateral breast cancer patients (SBBC). The majority of patients received lumpectomy, axillary node dissection, and localized radiation therapy. Median tumor size was 1.4 cm for BBC and 1.5 cm for UBC patients. Median total dose to the tumor bed was 60 Gy for both unilateral and bilateral patients. Of the 44 MBBC patients, 14 received breast conservation for both the first and second lesions, while 30 received breast conservation for only the second metachronous lesion. Thus 58 lesions in 44 patients were treated with breast conservation therapy. Of the SBBC patients, 13 of 16 patients received breast-conserving therapy for both breasts, while 3 received a mastectomy for the second synchronous primary. Median follow-up was 50 months for SBBC patients, 45 months for MBBC patients, and 52 months for UBC patients. Local control and survival were analyzed in patients with SBBC, MBBC, and UBC. The interval to development of local recurrence and survival were calculated from the time of development of the second breast lesion in patients with MBBC. No differences were found for survival and failure-free survival in patients with SBBC, MBBC, or UBC. Five-year overall survival by lifetable analysis was 76% for SBBC, 78% for MBBC, and 87% for UBC patients (p = 0.32 by log-rank analysis). The 5-year failure-free survival was 79% for SBBC, 73% for MBBC, and 85% for UBC patients (p = 0.28 by log-rank analysis). No significant differences were seen for median age, tumor size, pathologic node status, tamoxifen use, chemotherapy use, or median total radiation dose for SBBC, MBBC, or UBC patients. A significant difference was found in the incidence of family history of breast cancer in patients with unilateral versus bilateral breast cancer (p = 0.028 by chi-square analysis). However, there was no difference in outcome of patients by family history of breast cancer. The local control was identical in both BBC and UBC patients, with a local failure rate of 3%. Therefore, breast conservation therapy in local-regional, early stage breast cancer is a rational and efficacious treatment modality for patients with SBBC, MBBC, and UBC.     

Chromosome analysis of human refrozen embryos following fluorescence in situ hybridization

Purpose  Several recent reports have discussed refrozen and thawed embryo transfer; however, the process may cause a degree of chromosomal damage and subtle genomic mutation. In view of this possibility, the purpose of this study was to investigate the incidence of aneuploidy in refrozen embryos. Methods  In order to investigate the incidence of aneuploidy and mosaicism observed in chromosome 1, fluorescent in situ hybridization (FISH) was used on surviving embryos that first underwent one freeze-thaw cycle, then were allowed to develop to the blastocyst stage, and subsequently survived a second freeze-thaw cycle. Results  Of 1,132 blastomeric nuclei analyzed from 15 refrozen embryos, disomy was found in 82.9%. In contrast, for the 11 blastocysts subjected to only one freeze-thaw cycle, disomy was noted in 78.4%. Of the 197 blastomeric nuclei analyzed in all arrested embryos, disomy was found in 51.8%. Conclusions  The refreezing process did not increase aneuploidy. The good and fair morphology groups demonstrated a higher percentage of disomy than the poor morphology group regardless of whether they were frozen once or twice.