[Clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma of the breast].

Objective: To investigate the clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma (MSCC) of the breast. Methods: A total of 47 MSCC cases diagnosed in the Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China from January 2010 to December 2021 were reviewed. The clinical information (including the follow-up data of HER2 positive patients) and pathological features were collected and analyzed. Results: All of the patients were female. Among the 47 cases, 25 were pure squamous cell carcinoma (PSCC) and 22 were mixed metaplastic carcinoma with squamous cell component (MMSC). The median age of the patients was 54 years (range, 29-84 years). The maximum diameter of the mass ranged from 0.8 to 10.0 cm, with a mean value of 3.3 cm, 85.7% (24/28) of the cases were smaller than 5 cm, and only 4 cases were larger than or equal to 5 cm. 89.5% of the MMSC presented with a solid mass. Cystic changes were more commonly found in the PSCC group (50%, P<0.05) than the MMSC group. 36.7% (11/30) of the patients had lymph node metastasis at the time of diagnosis. The squamous cell carcinoma component in all cases showed diffuse or patchy expression of p63, p40 and CK5/6. 55.3% (26/47) of the cases showed triple-negative phenotype. Among the 7 HER2-positive patients, 6 were MMSC group, which had a significantly higher rate of HER2-positivity than that in the PSCC group (1 case). In 1 MMSC case, immunohistochemistry showed HER2 2+in the invasive ductal carcinoma component and HER2 negativity (0) in the squamous cell carcinoma component, but HER2 FISH was negative in invasive ductal carcinoma and positive in squamous cell carcinoma component. Six HER2-positive MSCC patients received anti-HER2-targeted therapy, including two patients who received neoadjuvant chemotherapy combined with anti-HER2-targeted therapy before surgery. One patient achieved pathological complete remission, while the other achieved partial remission (the residual tumors were squamous cell carcinoma components). After 9-26 months of follow-up, four patients had no disease progression, two patients developed pulmonary metastases, and one patient showed local recurrence. Conclusions: MSCC is a group of heterogeneous diseases. PSCC and MMSC may be two different entities. Most of the MSCC are triple-negative and HER2 positivity is more commonly seen in MMSC with invasive ductal carcinoma component. Some HER2-positive MSCC patients can achieve complete remission or long-term progression-free survival after receiving anti-HER2 targeted therapy, but the squamous cell carcinoma component may be less sensitive to targeted therapy than the invasive ductal carcinoma component.

The role of mitochondrial DNA mutations in coronary heart disease.

Coronary heart disease (CHD) is a leading cause of death worldwide. It is a multifactorial disorder resulting from harmful interactions between genetic and environmental factors. Due to the central role of mitochondria in cellular energy homeostasis, there is growing evidence supporting the role of damage to mitochondrial components such as mitochondrial DNA (mtDNA) in the pathogenesis and progression of CHD. However, the molecular mechanisms linking mtDNA and CHD remains unknown. In terms of mutations, we found that mitochondrial transfer RNA (mt-tRNA) genes are hot spots for pathogenic mutations associated with CHD. These mutations cause structural and functional changes in tRNA; specifically, failure of tRNA metabolism may impair mitochondrial protein synthesis and lead to mitochondrial dysfunction responsible for CHD. This review provides a detailed summary of the mtDNA mutations that have been reported to be associated with CHD and further discusses the possible molecular mechanisms behind the involvement of these mtDNA mutations in CHD.

LncRNA BC200 regulates the cell proliferation and cisplatin resistance in non-small cell lung cancer via PI3K/AKT pathway.

OBJECTIVE: Long non-coding RNA (lncRNA) exerts tissue specificity and regulates the occurrence and progression of tumors. Previous bioinformatics showed that lncRNA BC200 is served as an oncogene. However, the specific role of BC200 in lung cancer (LC) is rarely reported. The aim of this study is to elucidate the regulatory effects of BC200 on tumor development and cisplatin resistance in non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: The expression level of BC200 in 76 pairs of NSCLC tissues and adjacent normal tissues was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Correlation analyses were conducted to investigate the relation between BC200 expression and prognosis of NSCLC patients. Subsequently, BC200 expression in LC cell lines was detected. After construction of si-BC200 and si-NC, the cellular functions of LC cells were detected through colony formation, flow cytometry and transwell assay, respectively. Western blot was performed to detect the protein expressions of key genes in the PI3K/AKT pathway in LC cells. Finally, cell counting kit-8 (CCK-8) assay was carried out to explore the effect of BC200 on cisplatin resistance of LC cells via calculating IC50. RESULTS: Higher expression of BC200 was found in NSCLC tissues than that of adjacent normal tissues. BC200 expression was positively correlated with tumor stage, lymph node metastasis and distant metastasis of NSCLC patients, whereas not correlated to age and sex. Knockdown of BC200 inhibited proliferation, invasion and migration of LC cells. Western blot results showed that protein expressions of PI3K, AKT and STAT3 were downregulated after BC200 knockdown in LC cells. Additionally, the IC50 in H1299/DDP cells transfected with si-BC200 was lower than in those transfected with si-NC. The apoptotic rate in H1299 cells transfected with si-BC200 was remarkably lower than those transfected with si-NC. CONCLUSIONS: BC200 is highly expressed in NSCLC, which is positively correlated with tumor stage and metastasis of NSCLC patients. BC200 promotes the malignant progression of NSCLC via regulating cisplatin-induced apoptosis of H1299/DDP cells.

Cell proliferation and Ca(2+)-calmodulin dependent protein kinase activation mediated by alpha 1A- and alpha 1B-adrenergic receptor in HEK293 cells.

AIM: To examine the ability of alpha 1-AR subtypes on proliferation and Ca(2+)-calmodulin dependent protein kinase (CCDPK, formerly called MAPK) activation in transfected human embryo kidney 293 (HEK293) cells. METHODS: pREP8/alpha 1A-AR, pREP4/alpha 1B-AR, and pREP9/alpha 1D-AR were transfected, respectively, into HEK293 cells by calcium phosphate precipitation. The expression of alpha 1-AR was detected by radioligand binding assays. DNA synthesis was measured by [3H]thymidine incorporation. CCDPK activity was determined by immunoprecipitation method and myelin basic protein was used as substrate. RESULTS: Three clonal HEK293 cell lines stably expressing alpha 1A- or alpha 1B- or alpha 1D-AR were chosen and characterized by radioligand binding assay with receptor densities of about 0.6 nmol.g-1. Treatment with norepinephrine (NE) in the presence of propranolol for 24 h increased DNA synthesis in HEK293/alpha 1A- or HEK293/alpha 1B-AR cells concentration-dependently, with EC50 values of 48.8 nmol.L-1 (95% confidence limits 9.7-246 nmol.L-1) and 8.4 nmol.L-1 (95% confidence limits 2.1-32.9 nmol.L-1), respectively. The increase of DNA synthesis induced by NE 10 mumol.L-1 was 201% +/- 28% and 269% +/- 44% of basal, and the activation of CCDPK was 171% +/- 84% and 292% +/- 92% of basal in HEK293/alpha 1A-AR and HEK293/alpha 1B-AR cells, respectively. Preincubation with prazosin completely abolished NE-induced CCDPK activation in HEK293/alpha 1A- and alpha 1B-AR cells. Those changes were not found in HEK293/alpha 1D-AR cells. CONCLUSION: The activation of alpha 1A- or alpha 1B-AR but not alpha 1D-AR induces cell proliferation.

Tyrosine kinase participates in alpha 1A-adrenoceptor-mediated increase of intracellular calcium in human embryo kidney 293 cells.

AIM: To determine the role of protein-tyrosine kinase (PTK) in alpha 1A-adrenoceptor-mediated increase of [Ca2+]i (intracellular calcium) in human embryo kidney (HEK) 293 cells expressed alpha 1A-adrenoceptor. METHODS: Effects of two PTK inhibitors: genistein and tyrphostin, were investigated on the increase of [Ca2+]i by using Fura-2, The activity of PTK was measured and the accumulation of [3H] InsPs were observed. RESULTS: Norepinephrine stimulated a rapid increase in [Ca2+]i to (371 +/- 31) nmol.L-1 in HEK 293 cells. Norepinephrine-induced increase of [Ca2+]i was inhibited by the tyrosine kinase inhibitors quercetin and tyrphostin by 23.8% and 21.4%, respectively, but the accumulation of [3H]InsPs induced by norepinephrine was not. The activity of the plasma-associated tyrosine kinase was increased to (1.73 +/- 0.72)-fold over the control by norepinephrine 10 mumol.L-1. The norepinephrine-activated PTK was inhibited by calphostin C and depletion of intra- and extra-cellular Ca2+. CONCLUSION: The PTK participates in mobilization of Ca2+ mediated by alpha 1A-adrenoceptors in HEK 293 cell lines.

No functional beta 3-adrenergic receptors expressed in rat skeletal muscle cells.

AIM: To determine the functional role of beta 3-adrenoceptors (beta 3-AR) in rat skeletal muscle cells. METHODS: Nonselective beta-AR agonist isoprenaline (isoproterenol, Iso), beta 3-AR agonist CGP12177A which is a beta 1-/beta 2-AR antagonist and selective beta 3-AR antagonist SR59230A on cAMP accumulation was studied in primary cultured rat skeletal muscle cells. RESULTS: Iso stimulated cAMP accumulation in a concentration-dependent manner with EC50 of 1.51 nmol.L-1 and propranolol inhibited cAMP accumulation stimulated by Iso with KB of 3.47 nmol.L-1. CGP12177A had no effect on cAMP accumulation but inhibited cAMP production induced by Iso. SR59230A 10 nmol.L-1 did not inhibit cAMP production induced by Iso. CONCLUSION: The functional beta 3-AR are not present or at least not coupled to adenylyl cyclase activity in skeletal muscle cells.