Mechanism of miR-506 Targeting Autophagy and Apoptosis-Associated Gene Beclin1 to Promote Bone Marrow Mesenchymal Stem Cells (BMSCs) Differentiation and Metastasis to Breast Cancer

This study investigates miR-506 targeting the autophagy and apoptosis-related gene Beclin1 and analyzes the mechanism of its effect on bone marrow mesenchymal stem cells (BMSCs) differentiation and metastasis to breast cancer. Detection of miRNA-506 expression in BMSCs and breast cancer cells was done by Real-time PCR. A luciferase reporter system analyzed the targeting relationship between Beclin1 and miR-506. miR-NC group, BMSCs induction group, siRNA-NC group, and siRNA-Beclin1 group was set to measure Beclin1 expression, cell differentiation and migration by transwell assay, cell viability by MTT assay, proliferation by EdU staining and apoptosis and cycle by flow cell assay. miRNA-506 showed a high expression in breast cancer cells and low expression in BMSCs. miRNA-506 mimics significantly promote breast cancer cell proliferation which was inhibited by miRNA-506 inhibitors. The expression of Beclin1mRNA was significantly higher and miR-506 was lower in breast cancer cells. BMSCs induction significantly downregulated Beclin1 expression, increased miR-506 expression, and promoted cell invasive differentiation and metastatic capacity. In conclusion, elevated miR-506 expression was associated with decreased Beclin1 expression and increased metastatic differentiation capacity of breast cancer cells, which could effectively increase differentiation capacity and metastatic differentiation after induction by BMSCs.

Primary Hepatic Neuroendocrine Tumor and its Metastasis to Breast; Case Report of an Unusual Malignancy

Introduction: Neuroendocrine tumors (NETs) are rare tumors with varied clinical presentations. Entero-pancreatic and respiratory systems are usually involved but it can also affect unusual sites like the liver. Purpose: This paper presents a case of a 45 years female who developed progressive and disabling symptoms of mass effect and carcinoid but remained undiagnosed for many years due to extremely low suspicion of such a tumor in liver. Methods: Diagnosis was made after extensive radiological, histopathological, and biochemical investigations. By that time, disease had spread to her breast which is also not a typical feature of NETs. Findings: Diagnosis of rare tumors at an unusual site is challenging and requires high clinical suspicion and appropriate workup.

Appendiceal neuroendocrine tumour presenting as bilateral ovarian and breast metastasis

Neuroendocrine tumours (NETs) of the appendix (formerly known 'carcinoids') are rare and are usually detected incidentally after appendectomy. The reported frequency of metastases from appendiceal carcinoids is gradually increasing, may be due to the increased longevity of the patients with benign/malignant diseases. Here we report a case of NET of appendix in an 80 year old female who presented with bilateral ovarian mass, and later developed metastasis in the breast. Though uncommon, NETs producing bilateral ovarian metastasis is well described in literature, the commonest primary being ileum. Only few cases of neuroendocrine tumor metastasis to breast have been reported in the literature, but none from appendix as primary.