Radioresistance is a major factor leading to the failure of radiotherapy and poor prognosis in tumor patients. Following the application of radiotherapy, the activity of various metabolic pathways considerably changes, which may result in the development of resistance to radiation. Here, we discussed the relationships between radioresistance and mitochondrial and glucose metabolic pathways, aiming to elucidate the interplay between the tumor cell metabolism and radiotherapy resistance. In this review, we additionally summarized the potential therapeutic targets in the metabolic pathways. The aim of this review was to provide a theoretical basis and relevant references, which may lead to the improvement of the sensitivity of radiotherapy and prolong the survival of cancer patients.

Nasopharyngeal carcinoma (NPC) poses one of the serious health problems in southern Chinese, with an incidence rate ranging from 15 to 50/100,000. Chromosome translocation t(1;3) and frequent loss of heterogeneity on short arms of chromosome 3 and 9 have been reported to be associated with NPC, and a genome-wide scan identified an NPC susceptibility locus on chromosome 4p15.1-q12 recently. In our study, we collected samples from 18 families at high risk of NPC from the Hunan province in southern China, genotyped with a panel of polymorphic markers on short arms of chromosomes 3, 9, and 4p15.1-q12. A locus on 3p21 was identified to link to NPC with a maximum logarithm of odds for linkage score of 4.18. Fine mapping located the locus to a 13.6-cM region on 3p21.31-21.2, where a tumor suppressor gene cluster resided. Our findings identified a novel locus for NPC and provided a map location for susceptibility genes candidates. In contrast to a recent study, no significant evidence for NPC linkage to chromosomes 4 and 9 was observed.

Familial essential tremor (ET), the most common inherited movement disorder, is generally transmitted as an autosomal dominant trait. A genome-wide scan for ET revealed one major locus on chromosome 3q13. Here, we report that the Ser9Gly variant in the dopamine D ₃ receptor gene ( DRD3 ), localized on 3q13.3, is associated and cosegregates with familial ET in 23 out of 30 French families. Sequencing revealed no other nonsynonymous variants in the DRD3-coding sequence and in the first 871 bp of the 5’ flanking region. Moreover, Gly-9 homozygous patients presented with more severe and/or earlier onset forms of the disease than heterozygotes. A replication study comparing 276 patients with ET and 184 normal controls confirmed the association of the Gly-9 variant with risk and age-at-onset of ET. In human embryonic kidney (HEK) 293-transfected cells, the Gly-9 variant did not differ from the Ser-9 variant with respect to glycosylation and to anterograde and retrograde trafficking, but dopamine had an affinity that was four to five times higher. With the Gly-9 variant, the dopamine-mediated cAMP response was increased, and the mitogen-associated protein kinase (MAPK) signal was prolonged, as compared with the Ser-9 variant. The gain-of-function produced by the Gly-9 variant may explain why drugs active against tremor in Parkinson's disease (PD) are usually not effective in the treatment of ET and suggests that DRD3 partial agonists or antagonists should be considered as novel therapeutic options for patients with ET.