DNA damage checkpoint genes, such as p53, are frequently mutated in human cancer, but the selective pressure for their inactivation remains elusive. We analysed a panel of human lung hyperplasias, all of which retained wild-type p53 genes and had no signs of gross chromosomal instability, and found signs of a DNA damage response, including histone H2AX and Chk2 phosphorylation, p53 accumulation, focal staining of p53 binding protein 1 (53BP1) and apoptosis. Progression to carcinoma was associated with p53 or 53BP1 inactivation and decreased apoptosis. A DNA damage response was also observed in dysplastic nevi and in human skin xenografts, in which hyperplasia was induced by overexpression of growth factors. Both lung and experimentally-induced skin hyperplasias showed allelic imbalance at loci that are prone to DNA double-strand break formation when DNA replication is compromised (common fragile sites). We propose that, from its earliest stages, cancer development is associated with DNA replication stress, which leads to DNA double-strand breaks, genomic instability and selective pressure for p53 mutations.
Hyperhidrosis is caused by a sympathetic dysfunction of the central or peripheral nervous system. Intramedullary spinal cord lesions can be a cause of hyperhidrosis. The authors report a rare case of intramedullary thoracic spinal cord ganglioglioma presenting as hyperhidrosis. This 16-year-old boy presented with abnormal sweating on the right side of the neck, chest, and the right arm that had been occurring for 6 years. Neurological examination revealed mild motor weakness of the right lower extremity and slightly decreased sensation in the left lower extremity. Hyperhidrosis was observed in the right C3–T8 dermatomes. Magnetic resonance imaging showed an intramedullary tumor at the right side of the spinal cord at the T2–3 level. The tumor showed partial enhancement after Gd administration. The patient underwent removal of the tumor via hemilaminectomy of T2–3. Only subtotal resection was achieved because the margins of the tumor were unclear. Histopathological examination revealed ganglioglioma. Hyperhidrosis gradually improved after surgery. Hyperhidrosis is a rare clinical manifestation of intramedullary spinal cord tumors, and only a few cases have been reported in the literature. The location of the tumor origin, around the right gray matter of the lateral spinal cord, may account for the hyperhidrosis as the initial symptom in this patient. Physicians should examine the spinal cord using MRI studies when a patient has hyperhidrosis with some motor or sensory symptoms of the extremities.
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