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ABSTRACT Background: Triple-negative breast cancer (TNBC) is a subtype of breast cancer (BC) that lacks receptors for targeted therapy. Deeper insight into the molecular mechanisms regulating TNBC metastasis is urgently needed. The epithelial-mesenchymal transition process facilitates the metastasis of neighboring epithelial tumor cells. Protein kinase, membrane-associated tyrosine/threonine 1 (PKMYT1), a member of the Wee family of protein kinases, is upregulated in BC, and its high expression predicts poor prognosis in BC patients. Notch signaling activation is a pathognomonic feature of TNBC. PKMYT1 has been found to induce EMT in non-small cell lung cancer by activating Notch signaling. However, whether PKMYT1 exerts effects on TNBC progression by regulating Notch signaling remains unknown. Objectives: The objective of this study was to investigate whether PKMYT1 exerts effects on TNBC progression by regulating Notch signaling. Methods: Fifty cases of surgically resected BC samples (tumor and adjacent non-tumor tissue samples) were collected from patients diagnosed with BC. We measured the expression of PKMYT1 in clinical samples with real-time quantitative polymerase chain reaction (RT-qPCR). For in vitro analysis, RT-qPCR and Western blotting were conducted to evaluate PKMYT1 expression in TNBC cells. Then, the viability, migration, and invasion of TNBC cells were detected by cell counting kit-8 assays, wound healing assays, and Transwell assays. The EMT event was examined by evaluating the levels of EMT-associated proteins. For in vivo analysis, xenograft models in nude mice were established to explore PKMYT1 roles. E-cadherin and Ki67 expression in xenograft models were estimated by immunohistochemistry staining. Hematoxylin and eosin staining was performed to assess tumor metastasis. The underlying mechanisms by which PKMYT1 affected the malignant phenotypes of TNBC cells were explored by Western blotting measuring the pathway-associated proteins. Results: PKMYT1 was upregulated in BC tissues and cells, and its knockdown prevented cell proliferation, migration, invasion, and EMT event in TNBC. Mechanistically, Notch signaling was inactivated by PKMYT1 depletion, and Notch activation abolished the PKMYT1 silencing-induced inhibition in the malignant phenotypes of TNBC cells. For in vivo analysis, PKMYT1 knockdown inhibited tumorigenesis and metastasis of TNBC. Conclusion: PKMYT1 promotes EMT, proliferation, migration, and invasion of TNBC cells and facilitates tumor growth and metastasis by activating Notch signaling.
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@#[摘 要] 目的：探讨乳腺癌特异基因1（BCSG1）与Hsa-circ-0026352在浸润性乳腺癌（IBC）遗传易感性中的交互作用。方法：选取2019年6月至2022年5月间武汉市中西医结合医院收治的100例IBC患者作为研究对象，采用免疫组化法检测IBC组织及其相应癌旁组织中BCSG1的表达，将研究对象按照IBC组织中BCSG1蛋白表达的高低分为阴性、弱阳性和强阳性组，统计三组患者的临床病理特征及雌激素受体（ER）、孕激素受体（PR）、表皮生长因子受体-2（HER2）、Hsa-circ-0026352的表达情况，采用Logistic回归方程和最大似然法分析BCSG1表达与上述参数的趋势性和交互作用。结果：与癌旁组织比较，IBC组织中BCSG1蛋白呈高表达（P<0.05）；BCSG1蛋白强阳性表达与淋巴结转移、分化程度、临床分期、HER2表达、 Hsa-circ-0026352表达有关联（P<0.05）；BCSG1强阳性表达与IBC存在交互作用（P<0.05）；BCSG1表达与IBC的交互作用在Hsa-circ-0026352阳性表达中最为显著（趋势P<0.001）；BCSG1表达与IBC的交互作用在临床分期Ⅲ期、低分化程度中最为显著（趋势P<0.001）。结论：BCSG1与IBC患病密切相关，且与Hsa-circ-0026352、临床分期、分化程度存在交互作用，可共同增加IBC患病风险性。
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Diffuse pulmonary lymphangiomatosis (DPL) is a rare disease that is characterized by diffuse proliferation of abnormal pulmonary lymphatic channels. DPL occurs mostly in children and young adults and often undergoes a progressive clinical course, eventually causing deterioration of the lung. Both the clinical diagnosis and treatment of DPL remain a challenge. Here, we report a case of DPL in a 53-year-old Chinese woman with comprehensive investigations including pulmonary function tests, computer tomography (CT), bronchoscopy and histological examination of the lung biopsy, and review the literature.