MIEAP, a p53-downstream gene, is associated with suppression of breast cancer cell proliferation and better survival.

Mitochondria-eating protein (MIEAP; also known as SPATA18), a p53-downstream gene, is involved in mitochondrial quality control (MQC). Enforced MIEAP expression induces caspase-dependent cell death in vitro, and impairment of the p53/MIEAP-regulated MQC pathway is frequently observed in breast cancer (BC), resulting in poor disease-free survival (DFS). To investigate the clinical significance of MIEAP in BC, we identified 2,980 patients from two global, large-scale primary BC cohorts: the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC; n=1,904) and the Cancer Genome Atlas (TCGA; n=1,076). We divided patients in each cohort into high and low groups based on median gene expression levels and analyzed the association between MIEAP expression and clinical outcomes. Compared with normal tumors, MIEAP expression was significantly downregulated in all patients with p53-mutant BC regardless of subtype. MIEAP expression was negatively correlated with KI67 expression. Gene set enrichment analysis demonstrated that cell cycle- and proliferation-associated gene sets were significantly enriched in MIEAP-low tumors compared to MIEAP-high tumors. Patients with MIEAP-high luminal subtype were associated with significantly longer DFS than those with MIEAP-low luminal tumors in both cohorts, whereas significantly longer overall survival was observed only in the METABRIC cohort, which has roughly double the number of samples. These results indicated that the mechanistic role of MIEAP is clinically relevant in the two independent cohorts. This is the first study to use large cohorts to demonstrate the association between MIEAP expression and survival in patients with luminal subtype BC.

Nuclear localization of LDL receptor-related protein 1B in mammary gland carcinogenesis.

LRP1B intracellular domain is released and transported to the nucleus; however, pathological consequences of this nuclear transport are largely unclear. We aimed to unravel the pathobiological significance of nuclear localization of LRP1B intracellular domain in mammary gland carcinogenesis. Immunohistochemical staining using antibodies for LRP1B intracellular domain was performed to determine LRP1B expression in 92 invasive ductal breast carcinomas. LRP1B immunoreactivity was detected in the surface membrane and cytoplasm of 60 of 92 invasive ductal carcinomas and in the nucleus of 15 of 92 carcinomas. Nuclear LRP1B was significantly associated with poor patient prognosis, particularly luminal A type breast cancer, where it was significantly related to nodal metastasis. Doxycycline-dependent nuclear expression of LRP1B intracellular domain was established in cultured breast cancer cells. Enforced nuclear expression significantly increased Matrigel invasion activity in MCF-7 and T47D luminal A breast cancer cells. Moreover, enforced nuclear expression of LRP1B intracellular domain facilitated MCF-7 cells growth in mammary fat pad of nude mice, which was supplemented with estrogen. Comprehensive microarray-based analysis demonstrated that nuclear expression of LRP1B intracellular domain significantly increased long non-coding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) expression, which facilitates breast cancer invasion with poor prognosis. Nuclear-localized LRP1B intracellular domain promoted breast cancer progression with poor prognosis, possibly through the NEAT1 pathway. Nuclear transport of LRP1B intracellular domain could be a therapeutic target for breast cancer patients. KEY MESSAGES: Nuclear LRP1B was significantly associated with poor patient prognosis. Nuclear LRP1B increased Matrigel invasion activity of breast cancer cells. Nuclear expression of LRP1B intracellular domain increased NEAT1 expression.

The mode of progressive disease affects the prognosis of patients with metastatic breast cancer.

BACKGROUND: According to the Response Evaluation Criteria in Solid Tumors (RECIST), progressive disease (PD) is diagnosed under two conditions: an increase in size of pre-existing lesions (IS) and the appearance of new lesions (NL). We retrospectively investigated the difference in the prognosis between IS and NL. METHODS: Patients receiving drug therapies for metastatic breast cancer between 2004 and 2015 at our institution were reviewed. The survival time after NL and IS was compared and the frequency of NL with each drug calculated. RESULTS: For the 107 eligible patients, the survival time after NL at second-line chemotherapy was significantly worse than after IS (median survival time 4.3 months vs. 20.3 months, p = 0.0048). Maintenance therapy with bevacizumab or trastuzumab had a high frequency of NL (88.9%), and third-line eribulin had a low frequency of NL (16.7%). A multivariate analysis showed that NL at second-line chemotherapy was not an independent risk factor (hazard ratio 1.02, 95%; confidence interval 0.54-1.93, p = 0.95) for the total survival time. CONCLUSIONS: Patients with IS had a better survival after PD than those with NL. We may be able to avoid changing drug therapy for patients without NL and allow them to continue drug therapy for longer.

Age- and sex-dependency of the association between systemic antioxidant potential and glaucomatous damage.

Systemic oxidative stress is thought to be an important factor in the pathogenesis of glaucoma. In particular, low systemic antioxidative capacity, which normally counters oxidative stress, may contribute to glaucoma. Thus, we investigated the association between biological antioxidant potential (BAP), a biomarker of systemic antioxidative capacity, and glaucoma severity in patients with open-angle glaucoma (OAG). This study included 480 eyes of 240 patients with OAG and 66 healthy control eyes. We measured the BAP serum level with a free radical analyzer and compared it with a weighted estimate of the number of retinal ganglion cells (wrgc), derived from circumpapillary retinal nerve fiber layer thickness and visual field mean deviation. We found that wrgc was uncorrelated with BAP in the overall, male, and female OAG patients, but was correlated in young (aged ≤ 65 years) male OAG patients (better eye: r = 0.33, P = 0.02; worse eye: r = 0.27, P = 0.047). Furthermore, a mixed-effects regression analysis revealed that BAP was an independent contributing factor to wrgc in young male OAG patients (P = 0.02). Thus, systemic antioxidant capacity was associated with glaucomatous damage in relatively young male patients, suggesting that anti-oxidant therapy might be more effective in these patients.

A case of carcinoma of the papilla of Vater in a young man after subtotal colectomy for familial adenomatous polyposis.

BACKGROUND: Carcinoma and adenoma of the duodenum, including the papilla of Vater, are problematic diseases in patients with familial adenomatous polyposis (FAP). CASE PRESENTATION: A 36-year-old man underwent a periodic medical examination for early colon cancer originating from FAP for which laparoscopic-assisted subtotal colectomy with a J-shaped ileal pouch-rectal anastomosis was performed 3 years earlier. A tumor was detected at the papilla of Vater along with elevation of total bilirubin and hepatobiliary enzymes. Although cytology did not determine the tumor to be an adenocarcinoma, we suspected adenocarcinoma due to its hypervascularity shown by contrast-enhanced computed tomography. Pylorus-preserving pancreaticoduodenectomy with modified Imanaga reconstruction and regional lymph node dissection (D2) was performed. The pathological study showed that the tumor was a papillary and moderately differentiated tubular adenocarcinoma. The patient is currently in good health without recurrence, weight loss, or severe diarrhea at 12 months after surgery. CONCLUSIONS: Awareness of biliary-pancreatic symptoms and periodic gastroduodenoscopy might contribute both to the early detection of duodenal or periampullary polyps and cancer and to the radical treatment of FAP. Modified Imanaga reconstruction has the potential to become one of the more effective procedures for providing good quality of life to FAP patients with duodenal or periampullary cancer.

GPRC5B activates obesity-associated inflammatory signaling in adipocytes.

A genome-wide association study identified a strong correlation between body mass index and the presence of a 21-kb copy number variation upstream of the human GPRC5B gene; however, the functional role of GPRC5B in obesity remains unknown. We report that GPRC5B-deficient mice were protected from diet-induced obesity and insulin resistance because of reduced inflammation in their white adipose tissue. GPRC5B is a lipid raft-associated transmembrane protein that contains multiple phosphorylated residues in its carboxyl terminus. Phosphorylation of GPRC5B by the tyrosine kinase Fyn and the subsequent direct interaction with Fyn through the Fyn Src homology 2 (SH2) domain were critical for the initiation and progression of inflammatory signaling in adipose tissue. We demonstrated that a GPRC5B mutant lacking the direct binding site for Fyn failed to activate a positive feedback loop of nuclear factor κB-inhibitor of κB kinase ε signaling. These findings suggest that GPRC5B may be a major node in adipose signaling systems linking diet-induced obesity to type 2 diabetes and may open new avenues for therapeutic approaches to diabetic progression.

Comparison of recombinant protein expression in a baculovirus system in insect cells (Sf9) and silkworm.

Using a hybrid baculovirus system, we compared the expression of 45 recombinant proteins from six categories using two models: silkworm (larvae and pupae) and an Sf9 cell line. A total of 45 proteins were successfully expressed; preparation of hybrid baculovirus was unsuccessful for one protein, and two proteins were not expressed. A similar pattern of expression was seen in both silkworm and Sf9 cells, with double and multiple bands found in immunoblotting of the precipitate of both hosts. Degraded proteins were seen only in the silkworm system (particularly in the larvae). Production was more efficient in silkworms; a single silkworm produced about 70 times more protein than 10(6) Sf9 cells in 2 ml of culture medium.