No abstract

Background: The mechanism of metastasis-associated lung adenocarcinoma transcript 1 (Malat1) in triple-negative breast cancer (TNBC) is still unclear. Objective: This study aimed to investigate the role of miR-141-3p and Malat1 in autophagy in TNBC under hypoxia. Method: The expression levels of Malat1 and miR-141-3p were detected via quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression levels of hypoxia-inducible factor 1α (HIF-1α), HIF-2α, MMP9, p62 and LC3 were determined via western blotting. A Cell Counting Kit-8 assay was used to detect cell viability, while a Transwell assay to detect cell proliferation and invasion. A luciferase assay was used to confirm the relationship between Malat1 and miR-141-3p. Results: A significant increase was observed in the expression level of Malat1 and the autophagic activity in TNBC tissues and cells. The expression level of Malat1 was higher in a hypoxic environment, which can significantly promote the proliferation, migration, and invasion of TNBC cells by activating autophagy. HIF-1α, but not HIF-2α, was identified to induce the upregulation of Malat1 in TNBC cells. The dual-luciferase assay results identified a miR-141-binding site in Malat1. Malat1 knockdown and miR-141-3p overexpression were demonstrated to significantly inhibit autophagy, thereby inhibiting cell proliferation, invasion, and migration. Moreover, hypoxia can inhibit the effect of miR-141-3p on TNBC cells. Conclusion: miR-141-3p could suppress autophagy and inhibit proliferation, migration, and invasion by targeting Malat1 in TNBC cells under hypoxia. The existence of the HIF-1α/Malat1/miR-141 axis plays a vital role in the development of TNBC and may be a target for the diagnosis and treatment of TNBC.

Rationale: Granular cell tumor (GCT) of the vulva is an exceptionally rare female genital tract tumor. The majority of these are benign and there are no standardized surgical techniques for the special site to reduce tension of the wound. Patient concerns: A 47-years-old Chinese woman experienced a nodule on her right vulva with itch sometimes in late 2018. Diagnoses: Magnetic resonance imaging showed a high possibility of vulvar cancer. While Chest X-ray, abdominal sonography, and cystoscopy examination were unremarkable. Interventions: The patient underwent local complete resection of vulvar tumor under general anesthesia on March 24, 2022. The resection scope was approximately 4 cm × 3 cm × 3 cm. Due to the large surgical incision, Z-plasty was performed to achieve the primary closure for decreasing wound tension and improving aesthetic reduction. Outcomes: The final pathological diagnosis was benign GCT of the vulva and surgical margins were uninvolved. At 8 months follow-up, no new lesions were detected. Lessons: Surgery with negative resection margins is the mainstay for benign GCT of the vulva, while Z-plasty is appropriate for decreasing the tension of the wound and improving aesthetic reduction.