Macrocybin, a Natural Mushroom Triglyceride, Reduces Tumor Growth In Vitro and In Vivo through Caveolin-Mediated Interference with the Actin Cytoskeleton.

Mushrooms have been used for millennia as cancer remedies. Our goal was to screen several mushroom species from the rainforests of Costa Rica, looking for new antitumor molecules. Mushroom extracts were screened using two human cell lines: A549 (lung adenocarcinoma) and NL20 (immortalized normal lung epithelium). Extracts able to kill tumor cells while preserving non-tumor cells were considered "anticancer". The mushroom with better properties was Macrocybe titans. Positive extracts were fractionated further and tested for biological activity on the cell lines. The chemical structure of the active compound was partially elucidated through nuclear magnetic resonance, mass spectrometry, and other ancillary techniques. Chemical analysis showed that the active molecule was a triglyceride containing oleic acid, palmitic acid, and a more complex fatty acid with two double bonds. The synthesis of all possible triglycerides and biological testing identified the natural compound, which was named Macrocybin. A xenograft study showed that Macrocybin significantly reduces A549 tumor growth. In addition, Macrocybin treatment resulted in the upregulation of Caveolin-1 expression and the disassembly of the actin cytoskeleton in tumor cells (but not in normal cells). In conclusion, we have shown that Macrocybin constitutes a new biologically active compound that may be taken into consideration for cancer treatment.

[Recurrent benign multicystic peritoneal mesothelioma: Approach to this rare condition]. / Mesotelioma multiquístico peritoneal benigno recidivante: abordaje de esta entidad tan poco frecuente.

BACKGROUND: Benign multicystic mesothelioma is a rare benign tumour derived from the peritoneal mesothelium. The aim of this paper is to present a case of this rare tumour and review the clinical features, diagnosis and treatment of this disease. CLINICAL CASE: The case is presented of a 22-year-old female diagnosed with multicystic mesothelioma after an urgent resection of intra-abdominal tumour in the context of acute abdominal pain. In the subsequent follow-up, the patient had a recurrence of the lesion, and at 2 years was treated by further resection. CONCLUSIONS: Benign multicystic mesothelioma is a benign tumour of unknown origin, and with a non-specific clinical manifestation. The most effective treatment is surgical, although there is a high tendency to local recurrence.