Silica-Based Platform Decorated with Conjugated Polymer Dots and Prussian Blue for Improved Photodynamic Cancer Therapy.

To advance cancer treatment, we have developed a novel composite material consisting of conjugated polymer dots (CPDs) and Prussian blue (PB) particles, which were immobilized on, and encapsulated within, silica particles, respectively. The CPDs functioned as both a photosensitizer and a photodynamic agent, and the PB acted as a photothermal agent. The silica platform provided a biocompatible matrix that brought the two components into close proximity. Under laser irradiation, the fluorescence from the CPDs in the composite material enabled cell imaging and was subsequently converted to thermal energy by PB. This efficient energy transfer was accomplished because of the spectral overlap between the emission of donor CPDs and the absorbance of acceptor PB. The increase in local temperature in the cells resulted in a significant increase in the amount of reactive oxygen species (ROS) generated by CPDs, in which their independent use did not produce sufficient ROS for cancer cell treatment. To assess the impact of the enhanced ROS generation by the composite material, we conducted experiments using cancer cells under 532 nm laser irradiation. The results showed that with the increase in local temperature, the generated ROS increased by 30% compared with the control, which did not contain PB. When the silica-based composite material was positioned at the periphery of the tumor for 120 h, it led to a much slower tumor growth than other materials tested. By using a CPD-based photodynamic therapy platform, a new simplified approach to designing and preparing cancer treatments could be achieved, which included photothermal PB-assisted enhanced ROS generation using a single laser. This advancement opens up an exciting new opportunity for effective cancer treatment.

Monocarboxylate transporter 9 (MCT9) is down-regulated in renal cell carcinoma.

BACKGROUND: The renal cell carcinoma (RCC) incidences are continuously increasing, however, their proper characterization remains difficult. Mammalian kidneys require large amounts of energy, and monocarboxylate transporter (MCT) gene family is responsible for the transport of monocarboxylic compounds across plasma membranes. OBJECTIVE: A total of 14 MCT members have been identified in humans, which show highly distinct substrate affinities and tissue distributions. To understand the yet-uncharacterized renal cancer-specific role of MCTs, we identified MCT members that are differentially regulated during the renal tumor progression. METHODS: We examined the expression level of MCT members in renal cell tumors and their relationship with survival rate of patients using a public database. Quantitative RT-PCR and northern blotting were performed to validate the expression of MCTs. Anti-MCT9 antiserum was raised in rabbit and used to examine MCT9 expression in normal and tumor tissue arrays. Effect of MCT9 overexpression on cell proliferation was measured using renal cancer cell lines. RESULTS: MCT9 was found to be abundantly and exclusively expressed in human kidney cells, and was highly downregulated in renal cancers. Kaplan-Meier plotter analysis revealed an increased survival rate of MCT9 high-expressing RCC patients. MCT9 proteins were detected in normal kidney tissue sections and their overexpression clearly attenuated renal cell proliferation. CONCLUSIONS: MCT9 was identified as a novel highly downregulated gene in renal cell cancer, and its overexpression clearly attenuated RCC cell proliferation. Thus, functional analysis of MCT9 may help in deciphering a yet-undiscovered kidney-specific energy metabolism during renal tumor progression.

Na/K-ATPase beta1-subunit associates with neuronal growth regulator 1 (NEGR1) to participate in intercellular interactions.

Neuronal growth regulator 1 (NEGR1) is a GPI-anchored membrane protein that is involved in neural cell adhesion and communication. Multiple genome wide association studies have found that NEGR1 is a generic risk factor for multiple human diseases, including obesity, autism, and depression. Recently, we reported that Negr1-/- mice showed a highly increased fat mass and affective behavior. In the present study, we identified Na/K-ATPase, beta1-subunit (ATP1B1) as an NEGR1 binding partner by yeast two-hybrid screening. NEGR1 and ATP1B1 were found to form a relatively stable complex in cells, at least partially co-localizing in membrane lipid rafts. We found that NEGR1 binds with ATP1B1 at its C-terminus, away from the binding site for the alpha subunit, and may contribute to intercellular interactions. Collectively, we report ATP1B1 as a novel NEGR1-interacting protein, which may help deciphering molecular networks underlying NEGR1-associated human diseases. [BMB Reports 2021; 54(3): 164-169].

MAM domain containing 2 is a potential breast cancer biomarker that exhibits tumour-suppressive activity.

OBJECTIVES: The aim of this study was to discover new potential biomarkers of breast cancer and investigate their cellular functions. MATERIALS AND METHODS: We analysed the gene expression profiles of matched pairs of breast tumour and normal tissues from 24 breast cancer patients. Tetracycline-inducible MAMDC2 expression system was established and used to evaluate cell proliferation in vitro and in vivo. MAMDC2-mediated signalling was determined using immunoblot analysis. RESULTS: We identified MAMDC2 as a down-regulated gene showing significant prognostic capability. Overexpression of MAMDC2 or treatment with MAMDC2-containing culture medium significantly inhibited the cell proliferation of T-47D cells. Furthermore, MAMDC2 expression reduced in vivo growth of T-47D xenograft tumours. MAMDC2 may exert its growth-inhibitory functions by attenuating the MAPK signalling pathway. CONCLUSION: We report that MAMDC2 has a tumour-suppressive role and, as a secretory protein, it might be useful as a biomarker for breast cancer treatment.

A foodborne outbreak of Staphylococcus aureus associated with fried chicken in Republic of Korea.

An outbreak of Staphylococcus aureus infections occurred in a university with an enrollment of 80 students in the city of Daejon, Republic of Korea. All nine S. aureus isolates from patients (n = 7), staff members (n = 1), and the fried chicken served as the lunch (n = 1) harbored the enterotoxin A gene and showed an identical antibioticresistant profile, PFGE banding pattern (STAS16.001), and sequence type, ST 6. These results suggested that the outbreak was associated with eating the fried chicken that had been handled by an infected staff member. This case report demonstrated a practical approach to identifying the source and transmission of an infection.