IKKβ overexpression together with a lack of tumour suppressor genes causes ameloblastic odontomas in mice

Odontogenic tumours are a heterogeneous group of lesions that develop in the oral cavity region and are characterized by the formation of tumoural structures that differentiate as teeth. Due to the diversity of their histopathological characteristics and clinical behaviour, the classification of these tumours is still under debate. Alterations in morphogenesis pathways such as the Hedgehog,MAPK and WNT/β-catenin pathways are implicated in the formation of odontogenic lesions, but the molecular bases of many of these lesions are still unknown. In this study, we used genetically modified mice to study the role of IKKβ(a fundamental regulator of NF-κB activity and many other proteins) in oral epithelial cells and odontogenic tissues. Transgenic mice overexpressing IKKβ in oral epithelial cells show a significant increase in immune cells in both the oral epithelia and oral submucosa. They also show changes in the expression of several proteins and mi RNAs that are important for cancer development. Interestingly, we found that overactivity of IKKβ in oral epithelia and odontogenic tissues, in conjunction with the loss of tumour suppressor proteins(p53, or p16 and p19), leads to the appearance of odontogenic tumours that can be classified as ameloblastic odontomas, sometimes accompanied by foci of secondary ameloblastic carcinomas. These tumours show NF-κB activation and increased β-catenin activity.These findings may help to elucidate the molecular determinants of odontogenic tumourigenesis and the role of IKKβ in the homoeostasis and tumoural transformation of oral and odontogenic epithelia.

Lack of evidence for germline WWP1 pathogenic variants in gastrointestinal polyposis and other phenotypes suggestive of PTEN-hamartoma-tumor syndrome

Germline activating variants in WWP1,which encodes an E3 ubiquitin ligase that antagonizes PTEN tumor suppressive function,have been proposed as an alternative mechanism of PTEN inactivation in PTEN-hamartoma-tumor syndrome(PHTS)-like patients with wildtype PTEN.1 More specifically,heterozygous,potentially activating wwP1 variants were first identified by Lee et al in patients affected with gastrointestinal oligopolyposis,including adenomatous,hyperplastic/serrated,and hamartomatous polyps,and occasionally with colorectal cancer(Table 1).Subsequently,based on the PHTS phenotypic features,wWP1 mutational screening was performed in patients with thyroid nodules,2 or normocephalic autism spectrum disorder(ASD),3 where germline WWP1 variants were also identified(Table S1).

Wnt genes in colonic polyposis predisposition

Much of the genetic predisposition to polyposis,and particularly to serrated polyposis(SP),remains unknown.Only germline pathogenic variants in RNF43,a tumor suppressor that exerts negative feedback in the Wnt/β-catenin signaling pathway,have been causally linked to some SP cases(<2%),a disease associated with increased risk of colorectal cancer(CRC).^(1) Most known hereditary CRC and polyposis genes affect DNA repair,BMP/TGF-β,or Wnt signaling,being the latter associated with adenomatous and serrated polyposis phenotypes.2 Based on this observation,we evaluated the presence and role of germline variants in those pathways in unsolved polyposis patients.

Engineering bionic T cells: signal 1, signal 2, signal 3, reprogramming and the removal of inhibitory mechanisms

Gene engineering and combinatorial approaches with other cancer immunotherapy agents may confer capabilities enabling full tumor rejection by adoptive T cell therapy(ACT).The provision of proper costimulatory receptor activity and cytokine stimuli,along with the repression of inhibitory mechanisms,will conceivably make the most of these treatment strategies.In this sense,T cells can be genetically manipulated to become refractory to suppressive mechanisms and exhaustion,last longer and differentiate into memory T cells while endowed with the ability to traffic to malignant tissues.Their antitumor effects can be dramatically augmented with permanent or transient gene transfer maneuvers to express or delete/repress genes.A combination of such interventions seeks the creation of the ultimate bionic T cell,perfected to seek and destroy cancer cells upon systemic or local intratumor delivery.