To be Wild or Mutant: Role of Isocitrate Dehydrogenase 1 (IDH1) and 2-Hydroxy Glutarate (2-HG) in Gliomagenesis and Treatment Outcome in Glioma.

Molecular and clinical research based on isocitrate dehydrogenase (IDH) mutations is much sought after in glioma research since a decade of its discovery in 2008. IDH enzyme normally catalyzes isocitrate to α-keto-glutarate (α-KG), but once the gene is mutated it produces an 'oncometabolite', 2-hydroxyglutarate (2-HG). 2-HG is proposed to inhibit α-KG-dependent dioxygenases and also blocks cellular differentiation. Here, we discuss the role of the IDH1 mutation in gliomagenesis. The review also focuses on the effect of 2-HG on glioma epigenetics, the cellular signaling involved in IDH1 mutant glioma cells and the therapeutic response seen in mutant IDH1(mIDH1) harboring glioma patients in comparison to the patients with wild-type IDH1. The review encompasses the debatable impacts of the mutation on immune microenvironment a propos of various mIDH1 inhibitors in practice or in trials. Recent studies revealing the relation of IDH mutation with the immune microenvironment and inflammatory status in untreated versus treated glioblastoma patients are highlighted with respect to prospective therapeutic targets. Also at the molecular level, the association of mIDH1/2-HG with the intracellular components such as mitochondria and other neighboring cells is discussed.

Unique presentation of occipital condyle giant cell tumor as occipital condyle syndrome - A review.

Giant cell tumors (GCTs) of the skull are rare and only a few case series with limited number of cases have been reported till date. In the cranium, GCT usually occurs in the sphenoid and temporal bone, occipital condyle GCTs are very rare. We report a rare presentation of GCT of the occipital condyle manifested as occipital condyle syndrome. Despite gross total resection, they can recur aggressively; the presence of cortical breach might be an indicator of aggressiveness prompting early post-operative imaging and adjuvant therapy.

MutT Homolog1 has multifaceted role in glioma and is under the apparent orchestration by Hypoxia Inducible factor1 alpha.

AIMS: The study focused on the expression and role of a recent potential cancer therapeutic target protein, MutT Homolog1 (MTH1). MTH1 gets activated in an increased reactive oxygen species (ROS) environment and removes the oxidized nucleotides from the cell. The study aimed to check the role of MTH1 in DNA damage and apoptosis, migration and angiogenesis and also to examine its regulation in glioma. MAIN METHODS: The experiments were carried out in human glioma tissue samples and brain tissues of epilepsy patients (non-tumor control). We used two human glioblastomas cell lines, U87MG and U251MG cells. In order to study the role of MTH1 in glioma and to analyze the relation of MTH1 with Hif1α, we have used MTH1 siRNA and Hif1α siRNA respectively. KEY FINDINGS: We found an increased expression of MTH1 in glioma tissues compared to the non-tumor brain tissues. Correlation analysis revealed that those samples showing reduced expression of MTH1 also had high levels of DNA damage and apoptotic markers, while diminished expression of angiogenesis regulators and levels of migration. MTH1 knockdown in vitro by siRNA in tumor cell lines corroborates the above observation. This justifies the emergence of MTH1 inhibitors as potential first-in-class drugs. Mechanistically, our observations suggest that Hif1α may modulate MTH1 expression. SIGNIFICANCE: We found elevated MTH1 expression in glioma irrespective of their grades, while its inhibition affects multiple tumor progression pathways, and that targeting Hif1α could simulate the same.

NK/T-cell lymphoma in a renal transplant recipient and review of literature.

T-cell lymphomas, particularly NK/T-cell lymphomas are rare post transplantation malignancies. Only a few cases have been described. These tumors behave aggressively and the outcome is poor. We present here a case of NK/T-cell lymphoma who presented to us with an orbital swelling 9 years after renal transplantation, along with the review of literature. To the best of our knowledge, this is the first case of NK/T-cell lymphoma post-renal transplantation reported from India.

Lipofibromatosis: report of a rare paediatric soft tissue tumour.

The clinical, radiological and pathological features of a case of lipofibromatosis, a rare paediatric soft tissue neoplasm, are described. The tumour involved the foot of a male infant and was present at birth. Magnetic resonance imaging showed a lipomatous mass, with splaying of muscles of the sole by lobules of fat. Histopathological examination revealed typical findings of an admixture of mature adipose tissue and fibroblastic elements. The radiological and pathological features helpful in differentiating this entity from other fibro-fatty paediatric soft tissue tumours is discussed, and the relevant literature is briefly reviewed.