Overexpression of miR-181a regulates the Warburg effect in triple-negative breast cancer

OBJECTIVE

Triple-negative breast cancer (TNBC) is highly aggressive and leads to a poor prognosis. microRNA-181a (miR-181a) exhibits strong antineoplastic effects in many types of cancer. In this study, we examine the responses of human miR-181a-transfected TNBC cells and explore the mechanisms underlying the observed effects.

METHODS

A series of cellular assays were conducted using cells from the MDA-MB-231 TNBC line to assess the impact of miR-181a overexpression. The extracellular acidification rate, lactate production and glucose uptake were evaluated as a measure of aerobic glycolysis (i.e. the Warburg effect). The expressions of glycolysis-related gene were analyzed.

RESULTS

Viability, migration and survival of miR-181a-transfected MDA-MB-231 cells were all significantly reduced. miR-181a inhibited glycolysis in TNBC cells by reducing the rates of glucose uptake and lactate production and a substantial downregulation of factors known to contribute to the Warburg effect, including the serine/threonine kinase, AKT3, hypoxia-inducible factor-1α (HIF-1α) and progesterone receptor membrane component 1 (PGRMC1).

CONCLUSION

Our results demonstrate that miR-181a may regulate glycolysis in MDA-MB-231 TNBC cells, potentially via interference with components of the AKT3-HIF-1α and PGRMC1 pathways. These results suggest that miR-181a might be developed as a therapeutic agent for use in antineoplastic regimens directed at TNBC and PGRMC1-overexpressing breast cancers.

[Necrotizing fasciitis caused by pseudomonas aeruginosa (an obervation)]

Necrotizing fasciitis is an exceptional and severe form of subcutaneous gangrene which requires early diagnosis and emergency treatment. We report the case of a 24 year old woman presenting with necrotizing fasciitis after pansinusitis resistant to treatment. The germ detected was pseudomonas aeruginosa. The infection was controled with intensive care, antibiotics and surgical resection of necrotic tissues. The aim of this observation is to highlight the clinical characteristics of this disease, and to insist on the necessity to recognize the early symptoms and to start treatment as soon as possible.

[Ophthalmic manifestations of acute leukemia]

Orbital and ocular lesions are the third most frequent extramedullar locations of acute leukemia after the meninges and testicles. These lesions are treated as a central nervous system lesion; therefore diagnosis is essential to therapeutic adjustment. We present a retrospective study on charts of children treated for acute leukemia between 1996 and 1998. Ophthalmic examination was carried out when there were ocular symptoms. One hundred ninety-six children were treated for acute leukemia. Twelve children (6.1%) had an ocular and orbital lesion: 7 boys and 5 girls, with an average age of 6 years. Six had acute lymphoblastic leukemia, 6 had acute myeloid leukemia. Visual acuity was 1/10 in 9 children. Four children had an initial orbital lesion with a rapidly progressing exophthalmos. The hemogram and myelogram showed a granulocytic sarcoma. Two children who had been previously treated for acute leukemia presented a bilateral anterior uveitis with hypopyon; anterior chamber paracentesis showed blast cells and confirmed the ocular relapse. A corneal lesion was found in 2 children and in 2 cases, the optic nerve had edema; a decrease in visual acuity was the sign of the optic nerve lesion. Two patients had retinal infiltration with hemorrhages in the posterior pole. Prophylaxis consists of intrathecal injection of methotrexate and reinforcement of chemotherapy. Central nervous system irradiation is seldom used in children. Orbital and ocular lesions carry a poor prognosis according to the majority of authors. Two years after diagnosis of the ocular lesions, only 1 of the children studied remains alive.

[Epithelial cyst in the superior internal angle: a case report]

Most orbital cysts in childhood are epidermoids or dermoids. We report one uncommon case of an 8-years old girl with a lacrimal orbital cyst revealed by discrete proptosis and pseudo-ptosis in which the cystic histopathological study revealed a lacrimal structure.