Bone is one of the most common metastatic sites of breast cancer, and bone metastasis profoundly affects the quality of life of breast cancer patients. Bone metastasis is commonly observed among all the subtypes of breast cancer; however, its molecular mechanism has been analyzed only in triple‐negative subtype of breast cancer (TNBC). To characterize the molecular mechanisms of bone metastasis of luminal breast cancer, we established a bone‐metastatic model of the MCF7, luminal breast cancer cell line, with enhanced osteolytic activity by intracaudal arterial injection (CAI). Pathological analysis of the established cell lines revealed that they exhibited fierce osteolytic ability by promoting osteoclast differentiation and activity. The signature genes extracted from highly osteolytic MCF7 cell lines were differed from those of bone‐metastatic TNBC cell lines. Our results suggest that unique mechanisms of osteolysis in bone‐metastatic lesions of luminal breast cancer. In addition, several up‐regulated genes in MCF7‐BM (Bone Metastasis) 02 cell lines correlated with poor prognosis with luminal breast cancer patients. Our findings support further study on the bone‐metastatic mechanisms of luminal breast cancer.

Bioluminescence imaging (BLI) is useful to monitor cell movement and gene expression in live animals. However, D-luciferin has a short wavelength (560 nm) which is absorbed by tissues and the use of near-infrared (NIR) luciferin analogues enable high sensitivity in vivo BLI. The AkaLumine-AkaLuc BLI system (Aka-BLI) can detect resolution at the single-cell level; however, it has a clear hepatic background signal. Here, to enable the highly sensitive detection of bioluminescence from the surrounding liver tissues, we focused on seMpai (C15H16N3O2S) which has been synthesized as a luciferin analogue and has high luminescent abilities as same as AkaLumine. We demonstrated that seMpai BLI could detect micro-signals near the liver without any background signal. The solution of seMpai was neutral; therefore, seMpai imaging did not cause any adverse effect in mice. seMpai enabled a highly sensitive in vivo BLI as compared to previous techniques. Our findings suggest that the development of a novel mutated luciferase against seMpai may enable a highly sensitive BLI at the single-cell level without any background signal. Novel seMpai BLI system can be used for in vivo imaging in the fields of life sciences and medicine.

, which contains polyglutamine tract of 13 (normal range) and 28 (SCA6 disease range) repeat units, respectively. Surprisingly, transfection with HC, HS, and HL gave essentially the same results: EGFP signal was observed in cell soma, dendrites, and the axon as well. Furthermore, mutation of the PDZ-binding motif located at the C-terminus of the long version of Ca v 2.1, by adding FLAG tag, did not affect the localization patterns of HS and HL as well. Therefore, the C-terminal region is not indispensable for the subcellular localization of Ca v 2.1 channel, nor expansion of polyglutamine length affected the localization of the channel. Thus, it is possible that the localization mechanism of Ca v 2.1 channel is different from that of Ca v 2.2, though these channels share various structural and functional characteristics.

The medaka, Oryzias latipes, has an XX/XY sex-determination system, and a Y-linked DM-domain gene, DMY, is the sex-determining gene in this species. Since DMY appears to have arisen from a duplicated copy of the autosomal DMRT1 gene 10 million years ago, the medaka Y chromosome is considered to be one of the youngest male-determining chromosomes in vertebrates. In the screening process of sex-reversal mutants from wild populations, we found a population that contained a number of XY females. PCR, direct sequencing, and RT-PCR analyses revealed two different null DMY mutations in this population. One mutation caused loss of expression during the sex-determining period, while the other comprised a large deletion in putative functional domains. YY females with the mutant-type DMY genes on their Y chromosomes were fully fertile, indicating that the X and Y chromosomes were functionally the same except for the male-determining function. In addition, we investigated the frequencies of the sex chromosome types in this population over four successive generations. The Y chromosomes bearing the mutant-type DMY genes were detected every year with no significant differences in their frequencies. These results demonstrate that aberrant Y chromosomes behaving as X chromosomes have been maintained in this population.

Clinically, the osteolytic phenotype is rare in prostate cancer (PCa), and the prognosis is generally worse than that of the osteoblastic phenotype. Osteoblastic prostate cancer (BPCa) is a major type of bone metastasis. Several factors responsible for osteogenesis have been identified, but the molecular mechanism of osteoblastic bone metastasis in PCa is not fully understood. Here, we show the osteogenic and tumor‐suppressive roles of SERPINA3 and LCN2 in BPCa. In a co‐culture of osteoblasts (OBs) and BPCa cells, SERPINA3 and LCN2 were remarkably upregulated in BPCa via OB‐derived extracellular vesicles, while they were not in the co‐culture of OBs and osteolytic prostate cancer (LPCa) cells. In both the co‐culture system and mouse xenograft experiments with intracaudal injection, enhanced expression of SERPINA3 and LCN2 in PCa led to osteogenesis. Additionally, the addition of SERPINA3 and LCN2 to BPCa cells significantly suppressed the proliferative potential. Retrospective analysis also confirmed that high expression levels of SERPINA3 and LCN2 were significantly correlated with a better prognosis. Our results may partially explain how osteoblastic bone metastasis develops and why the prognosis for BPCa is relatively better than that for LPCa.

Purpose: Uterine leiomyosarcoma is among the most aggressive gynecological malignancies. No effective treatment strategies have been established. This study aimed to identify novel therapeutic targets for uterine leiomyosarcoma based on transcriptome analysis and assess the preclinical efficacy of novel drug candidates. Experimental Design: Transcriptome analysis was carried out using fresh-frozen samples of six uterine leiomyosarcomas and three myomas. The Ingenuity Pathway Analysis was then used to identify potential therapeutic target genes for uterine leiomyosarcoma. Moreover, our results were validated using three independent datasets, including 40 uterine leiomyosarcomas. Then, the inhibitory effects of several selective inhibitors for the candidate genes were examined using the SK-UT-1, SK-LMS-1, and SKN cell lines. Results: We identified 512 considerably dysregulated genes in uterine leiomyosarcoma compared with myoma. The Ingenuity Pathway Analysis showed that the function of several genes, including CHEK1 and PLK1, were predicted to be activated in uterine leiomyosarcoma. Through an in vitro drug screening, PLK1 or CHEK1 inhibitors (BI 2536 or prexasertib) were found to exert a superior anti-cancer effect against cell lines at low nanomolar concentrations and induced cell cycle arrest. In SK-UT-1 tumor-bearing mice, BI 2536 monotherapy demonstrated a marked tumor regression. Moreover, the prexasertib and cisplatin combination therapy also reduced tumorigenicity and prolonged survival. Conclusion: We identified the upregulated expression of PLK1 and CHEK1; their kinase activity was considered to be activated in uterine leiomyosarcoma. BI 2536 and prexasertib demonstrate a significant anti-cancer effect; thus, cell cycle-related kinases may represent a promising therapeutic strategy for treating uterine leiomyosarcoma.

Background In vivo investigations with cancer cells have powerful tools to discover cancer progression mechanisms and preclinical candidate drugs. Among these in vivo experimental models, the establishment of highly malignancy cell lines with xenograft has been frequently used. However, few previous researches targeted malignancy-related genes whose protein levels translationally changed. Therefore, this study aimed to identify malignancy-related genes which contributed to cancer progression and changed at the protein level in the in vivo selected cancer cell lines. Methods We established the high malignancy breast cancer cell line (LM05) by orthotopic xenograft as an in vivo selection method. To explore the altered genes by translational or post-translational regulation, we analyzed the protein production by western blotting in the highly malignant breast cancer cell line. Functional analyses of the altered genes were performed by in vitro and in vivo experiments. To reveal the molecular mechanisms of the regulation with protein level, we evaluated post-translational modification by immunoprecipitation. In addition, we evaluated translational production by click reaction-based purification of nascent protein. Results As a result, NF-κB inducing kinase (NIK) increased at the protein level and promoted the nuclear localization of NF-κB2 (p52) and RelB in the highly malignant breast cancer cell line. The functional analyses indicated the NIK upregulation contributed to tumor malignancy via cancer-associated fibroblasts (CAFs) attraction and partially anti-apoptotic activities. Additionally, the immunoprecipitation experiment revealed that the ubiquitination of NIK decreased in LM05 cells. The decline in NIK ubiquitination was attributed to the translational downregulation of cIAP1. Conclusions Our study identified a dysregulated mechanism of NIK production by the suppression of NIK post-modification and cIAP1 translation. The aberrant NIK accumulation promoted tumor growth in the highly malignant breast cancer cell line.

Post-translational modifications and mRNA translation are frequently altered in human cancers. However, investigations to understand their roles in the cancer progression mechanism remain insufficient. In this research, we explored protein levels altered by translational or post-translational regulation by analyzing transcriptome and western blotting data of the highly malignant breast cancer cell lines. From these analyses, NIK was found to be upregulated at the protein level to predominantly activate the non-canonical NF-κB pathway in a breast cancer cell line. Furthermore, the increase in NIK protein production was attributed to the dysregulation of ubiquitin-proteasome system caused by a decrease in the translation of cIAP1. NIK upregulation contributed to tumorigenicity by regulating the expression of inflammatory response-related genes. Collectively, our study suggests that NIK is post-translationally modified and has the potential to be a therapeutic target and diagnostic marker for breast cancer.