The homeoprotein HOXB2 limits triple-negative breast carcinogenesis via extracellular matrix remodeling.

Homeobox genes and their encoded DNA-binding homeoproteins are master regulators of development. Consequently, these homeotic elements may regulate key steps in cancer pathogenesis. Here, using a combination of in silico analyses of large-scale patient datasets, in vitro RNAi phenotyping, and in vivo validation studies, we investigated the role of HOXB2 in different molecular subtypes of human breast cancer (BC). The gene expression signatures of HOXB2 are different across distinct BC subtypes due to various genetic alterations, but HOXB2 was specifically downregulated in the aggressive triple-negative subtype (TNBC). We found that the reduced expression of HOXB2 was correlated with the metastatic abilities (epithelial-to-mesenchymal transition) of TNBC cells. Further, we revealed that HOXB2 restrained TNBC aggressiveness by ECM organization. HOXB2 bound to the promoter regions of MATN3 and ECM2 and regulated their transcription levels. Forced expression of HOXB2 effectively prevented TNBC progression and metastasis in a mouse xenograft model. Reduction of HOXB2 and the HOXB2/MATN3/ECM2 transcriptional axis correlated with poor survival in patients with various cancers. Further, we found the long non-coding RNA HOXB-AS1 in complex with SMYD3, a lysine methyltransferase, as an epigenetic switch controlling HOXB2 expression. Overall, our results indicate a tumor-suppressive role of HOXB2 by maintaining ECM organization and delineate potential clinical utility of HOXB2 as a marker for TNBC patients.

Akt1 Decreases Gcn5 Protein Stability through Regulating The Ubiquitin-Proteasome Pathway in Mouse Embryonic Fibroblasts.

General control non-derepressible 5 (Gcn5) is a member of histone acetyltransferase (HAT) that plays key roles during embryogenesis as well as in the development of various human cancers. Gcn5, an epigenetic regulator of Hoxc11, has been reported to be negatively regulated by Akt1 in the mouse embryonic fibroblasts (MEFs). However, the exact mechanism by which Akt1 regulates Gcn5 is not well understood. Using protein stability chase assay, we observed that Gcn5 is negatively regulated by Akt1 at the post-translational level in MEFs. The stability of Gcn5 protein is determined by the competitive binding with the protein partner that interacts with Gcn5. The interaction of Gcn5 and Cul4a-Ddb1 complex predominates and promotes ubiquitination of Gcn5 in the wild-type MEFs. On the other hand, in the Akt1-null MEFs, the interaction of Gcn5 and And-1 inhibits binding of Gcn5 and Cul4a-Dbd1 E3 ubiquitin ligase complex, thereby increasing the stability of the Gcn5 protein. Taken together, our study indicates that Akt1 negatively controls Gcn5 via the proteasomal degradation pathway, suggesting a potential mechanism that regulates the expression of Hox genes.

Mitofusin-2 Promotes the Epithelial-Mesenchymal Transition-Induced Cervical Cancer Progression.

High expression of mitofusin-2 (MFN2), a mitochondrial fusion protein, has been frequently associated with poor prognosis of patients with cervical cancer. Here, we aimed to identify the function of MFN2 in cervical cancer to understand its influence on disease prognosis. To this end, from cervical adenocarcinoma, we performed an MTT assay and quantitative RT-PCR (qRT-PCR) analysis to assess the effects of MFN2 on the proliferation and of HeLa cells. Then, colony-formation ability and tumorigenesis were evaluated using a tumor xenograft mouse model. The migration ability related to MFN2 was also measured using a wound healing assay. Consequently, epithelial-mesenchymal transition (EMT) of MFN2-knockdowned HeLa cells originating from adenocarcinoma. markers related to MFN2 were assessed by qRT-PCR. Clinical data were analyzed using cBioPortal and The Cancer Genome Atlas. We found that MFN2 knockdown reduced the proliferation, colony formation ability, migration, and in vivo tumorigenesis of HeLa cells. Primarily, migration of MFN2-knockdowned HeLa cells decreased through the suppression of EMT. Thus, we concluded that MFN2 facilitates cancer progression and in vivo tumorigenesis in HeLa cells. These findings suggest that MFN2 could be a novel target to regulate the EMT program and tumorigenic potential in HeLa cells and might serve as a therapeutic target for cervical cancer. Taken together, this study is expected to contribute to the treatment of patients with cervical cancer.

NR4A1 Regulates Tamoxifen Resistance by Suppressing ERK Signaling in ER-Positive Breast Cancer.

Endocrine therapy is used to treat estrogen receptor (ER)-positive breast cancer. Tamoxifen is effective against this cancer subtype. Nonetheless, approximately 30% of patients treated with tamoxifen acquire resistance, resulting in therapeutic challenges. NR4A1 plays key roles in processes associated with carcinogenesis, apoptosis, DNA repair, proliferation, and inflammation. However, the role of NR4A1 in tamoxifen-resistant ER-positive breast cancer has not yet been elucidated. Here, we propose that NR4A1 is a promising target to overcome tamoxifen resistance. NR4A1 gene expression was downregulated in tamoxifen-resistant MCF7 (TamR) cells compared to that in MCF7 cells. Kaplan-Meier plots were used to identify high NR4A1 expression correlated with increased survival rates in patients with ER-positive breast cancer following tamoxifen treatment. Gain and loss of function experiments showed that NR4A1 restores sensitivity to tamoxifen by regulating cell proliferation, migration, invasion, and apoptosis. NR4A1 localized to the cytoplasm enhanced the expression of apoptotic factors. In silico and in vitro analyses revealed that NR4A1 enhanced responsiveness to tamoxifen by suppressing ERK signaling in ER-positive breast cancer, suggesting that the NR4A1/ERK signaling axis modulates tamoxifen resistance. These results indicate that NR4A1 could be a potential therapeutic target to overcome tamoxifen resistance in ER-positive breast cancer.

HOXB5 Confers Tamoxifen Resistance in Breast Cancer Cells and Promotes Tumor Aggression and Progression.

BACKGROUND/AIM: ER-positive breast cancer patients commonly undergo endocrine therapy with drugs such as tamoxifen. Despite tamoxifen being a highly effective drug, long-term treatment results in resistance in one-third of the patients. Although many explanations for the development of tamoxifen resistance have been put forward, a clearly defined underlying mechanism is still lacking. MATERIALS AND METHODS: The expression level of HOXB5 was evaluated between MCF7 breast cancer cells and tamoxifen-resistant MCF7 (TAMR) cells by RT-PCR. Then, the effect of HOXB5 on invasion and migration abilities as well as on cancer stemness were investigated through 3D culture and spheroid formation assay. RESULTS: In this study, we provide evidence that HOXB5 is up-regulated in TAMR cells. EGFR is concurrently overexpressed, and the EGFR signaling cascade is activated, resulting in migratory and invasive phenotypes in TAMR cells compared to MCF7 cells. However, HOXB5 knockdown in TAMR cells resulted in the de-activation of the EGFR signaling pathway, less aggressive phenotypes and restoration of sensitivity to tamoxifen treatment. More interestingly, TAMR cells expressed higher levels of stem cell markers, and as a result, their enhanced stemness allowed for a better formation of spheroids than MCF7 cells. When HOXB5 was overexpressed in MCF7 cells, they were able to form a larger number of spheroids as in TAMR cells. CONCLUSION: HOXB5 is one of the key factors involved in tumor aggression and progression in tamoxifen-resistant breast cancer cells.

HOXA5 confers tamoxifen resistance via the PI3K/AKT signaling pathway in ER-positive breast cancer.

Tamoxifen is a commonly used drug to treat estrogen receptor-positive patients with breast cancer. Despite the outstanding efficacy of tamoxifen, approximately one-third of patients develop resistance toward it, thereby presenting a therapeutic challenge. HOX genes may be involved in the acquisition of tamoxifen resistance. In this study, we identified HOXA5, a member of the HOX gene family, as a marker of tamoxifen resistance. Using ChIP assay, we found that HOXA5 expression was significantly overexpressed in tamoxifen-resistant MCF7 (TAMR) breast cancer cells because of reduced H3K27me3 binding. HOXA5 upregulation resulted in activation of the PI3K/AKT signaling cascade, which in turn, led to p53 and p21 reduction, ultimately making the TAMR cells less apoptotic. Furthermore, elevated HOXA5 expression resulted in breast cancer cells acquiring more mesenchymal-like and stem cell traits associated with aggressive breast cancer phenotypes. In conclusion, our results delineate a mechanism by which HOXA5 promotes tumorigenesis, cancer progression, and tamoxifen resistance in breast cancer cells.

Subjective Perception of Individuals with Physical Disabilities Regarding Exercise Equipment Use.

Rehabilitation exercise is effective for improving the health of persons with physical disabilities. However, there are limited studies on their perception of exercise equipment use. The purpose of this study was to investigate the subjectivity to understand the types of perceptions of individuals with physical disabilities regarding the use of exercise equipment in South Korea. This study used Q-methodology. A literature review and focus group interviews with individuals with physical disabilities were conducted to construct Q-Population. Q-statements were selected from the Q-population, after which Q-sorting was executed by P-sample. The results indicated 4 perception types: (1) "Independent user," (2) "Practical user," (3) "Motivational user," and (4) "Convenience user." Recommendations were provided for developing exercise equipment for use by individuals with physical disabilities. This study revealed 4 perception categories and the findings have strong potential to contribute to the development of proper services and the effective utilization of exercise equipment for individuals with physical disabilities.

Mitofusin-2 Promotes the EpithelialMesenchymal Transition-Induced Cervical Cancer Progression

High expression of mitofusin-2 (MFN2), a mitochondrial fusion protein, has been frequently associated with poor prognosis of patients with cervical cancer. Here, we aimed to identify the function of MFN2 in cervical cancer to understand its influence on disease prognosis.To this end, from cervical adenocarcinoma, we performed an MTT assay and quantitative RT-PCR (qRT-PCR) analysis to assess the effects of MFN2 on the proliferation and of HeLa cells. Then, colony-formation ability and tumorigenesis were evaluated using a tumor xenograft mouse model. The migration ability related to MFN2 was also measured using a wound healing assay. Consequently, epithelial-mesenchymal transition (EMT) of MFN2-knockdowned HeLa cells originating from adenocarcinoma. markers related to MFN2 were assessed by qRT-PCR. Clinical data were analyzed using cBioPortal and The Cancer Genome Atlas. We found that MFN2 knockdown reduced the proliferation, colony formation ability, migration, and in vivo tumorigenesis of HeLa cells. Primarily, migration of MFN2-knockdowned HeLa cells decreased through the suppression of EMT. Thus, we concluded that MFN2 facilitates cancer progression and in vivo tumorigenesis in HeLa cells. These findings suggest that MFN2 could be a novel target to regulate the EMT program and tumorigenic potential in HeLa cells and might serve as a therapeutic target for cervical cancer. Taken together, this study is expected to contribute to the treatment of patients with cervical cancer.

How Do Anticipated and Self Regulations and Information Sourcing Openness Drive Firms to Implement Eco-Innovation? Evidence from Korean Manufacturing Firms.

Building upon institutional theory and the concept of openness to external sources in terms of breadth and depth, this study investigates the following three understudied drivers of eco-innovation in terms of external and internal factors: Anticipated regulation and self-regulation as external drivers, and information sourcing openness comprised of breadth and importance as internal drivers. Toward this end, this study employs a sample of 1824 Korean manufacturing firms collected from the Korean Innovation Survey 2010, which is compatible with the Oslo Manual and the Eurostat Community Innovation Survey (CIS). The current research adopts a multivariate probit model for the nine binary outcome variables and a zero-inflated negative binomial (ZINB) regression model for a count variable. It is found that, both anticipated regulation and self-regulation positively affect eco-process innovation and eco-product innovation across all of the nine eco-innovation types. The empirical findings on the effects of the breadth of external sources and the importance of used information acquired from external sources for innovative activities indicate that both the breadth and the importance have positive impacts on the number of types of eco-innovation with which a firm is engaged.

Non-contact sound speed measurement by optical probing of beam deflection due to sound wave.

We report a non-contact and non-invasive method of sound speed measurement by optical probing of deflected laser beam due to normally incident degenerated shock wave. In this study the shock wave from an exploding wire was degenerated to an ordinary sound wave at the distance exceeding 0.23 m. Temporal resolution of the deflected beam signal was improved by passing through an adequate electronic high-pass filter, as a result we obtained a better temporal resolution than that of the acoustic pressure detection by PZT transducer in terms of rising time. The spatial resolution was improved by passing the refracted beam signal into the edge of focusing lens to make a larger deflection angle. Sound speed was calculated by monitoring the time of flight of transient deflected signal at the predetermined position. Sound speed has been measured in air, distilled water and acryl, agreed well with the published values. The sound speed measured in the solution of glycerin, magnesium sulfate (MgSO4), and dimethylformamide with various mole fractions also agrees within 3% of relative error with those measured in the present work by ultrasonic pulse echo method. The results suggest that the method proposed is to be reliable and reproducible.