TOP1 modulation during melanoma progression and in adaptative resistance to BRAF and MEK inhibitors.

In melanomas, therapy resistance can arise due to a combination of genetic, epigenetic and phenotypic mechanisms. Due to its crucial role in DNA supercoil relaxation, TOP1 is often considered an essential chemotherapeutic target in cancer. However, how TOP1 expression and activity might differ in therapy sensitive versus resistant cell types is unknown. Here we show that TOP1 expression is increased in metastatic melanoma and correlates with an invasive gene expression signature. More specifically, TOP1 expression is highest in cells with the lowest expression of MITF, a key regulator of melanoma biology. Notably, TOP1 and DNA Single-Strand Break Repair genes are downregulated in BRAFi- and BRAFi/MEKi-resistant cells and TOP1 inhibition decreases invasion markers only in BRAFi/MEKi-resistant cells. Thus, we show three different phenotypes related to TOP1 levels: i) non-malignant cells with low TOP1 levels; ii) metastatic cells with high TOP1 levels and high invasiveness; and iii) BRAFi- and BRAFi/MEKi-resistant cells with low TOP1 levels and high invasiveness. Together, these results highlight the potential role of TOP1 in melanoma progression and resistance.

Celiac Crisis: an unusual presentation of gluten-sensitive enteropathy.

Celiac disease (CD)-also known as gluten-sensitive enteropathy-is a chronic, genetically predisposing and autoimmune entity with a wide range of clinical manifestations triggered by gluten ingestion, which affects 1% of the general population. Currently, up to 60% of the diagnosis of CD is in adults due to the atypical course of the disease. The severe acute onset of CD-also called celiac crisis-is very uncommon and is still not well documented in adults. We report the case of a 58-year-old man who presented a 45-day history of subtle-onset diarrhea followed by malabsorption syndrome with progressive weight loss, anasarca, and electrolyte disturbances. The diagnostic work-up included an upper digestive endoscopy, which showed scalloping of the duodenal mucosa with pathological features confirmed on biopsies. Specific antibodies were positive, and a satisfactory clinical response was obtained once a gluten-free diet was started. Celiac crisis is a rare initial presentation of CD characterized by severe diarrhea, dehydration, weight loss, hypoproteinemia, and metabolic and electrolyte disturbances. Although rare, it should be considered in patients with apparently unexplained chronic diarrhea.

Multiple brain abscesses due to Penicillium spp infection.

We present a case of central nervous system (CNS) infection by a member of the Penicillium genera in a HIV-negative man in Brazil. The patient was admitted complaining of loss of visual fields and speech disturbances. CT scan revealed multiple brain abscesses. Stereotactic biopsies revealed fungal infection and amphotericin B treatment begun with initial improvement. The patient died few days later as a consequence of massive gastrointestinal bleeding due to ruptured esophageal varices. The necropsy and final microbiologic analyses disclosed infection by Penicillium sp. There are thousands of fungal species of the Penicillium genera. Systemic penicilliosis is caused by the P. marneffei and was formerly a rare disease, but now is one of the most common opportunistic infection of AIDS patients in Southeast Asia. The clinical presentation usually involves the respiratory system and the skin, besides general symptoms like fever and weight loss. Penicillium spp infection caused by species other than P. marneffei normally cause only superficial or allergic disease but rare cases of invasive disease do occur. We report the fourth case of Penicillium spp CNS infection.