MiRNA-106a-5p Promotes Laryngeal Carcinoma Proliferation and Migration Through PI3K/AKT/m-TOR Pathway by AKTIP.

Background: Laryngeal cancer (LC) remains one of the most common tumors of the respiratory tract, the exact pathogenesis remains unclear. MiRNA-106a-5p is aberrantly expressed in a variety of cancers and plays a pro- or anti-cancer role, but is indistinct in LC. Objectives: Showing the role of miRNA-106a-5p in the development of LC. Materials and Methods: Quantitative reverse transcription-polymerase chain reaction was used for miR-106a-5p measurement in clinical samples and LC cell lines (AMC-HN8 and TU212), first. The expression of miR-106a-5p was inhibited by inhibitor, then followed clonogenic and flow cytometric assays for cell proliferation; wood healing, and Transwell assays for cell migration. Dual luciferase reporter assay was performed for interaction verification, and the activation of the signal pathway was detected by western blots. Results: MiR-106a-5p was significantly over-expressed in LC tissues and cell lines. The proliferation ability of the LC cells was significantly reduced after miR-106a-5p inhibition, and most LC cells were stagnated in the G1 phase. The migration and invasion ability of the LC cells was decreased after the miR-106a-5p knockdown. Further, we found that miR-106-5a is bound with 3'-UTR of AKT interacting protein (AKTIP) mRNA specifically, and then activate PI3K/AKT/m-TOR pathway in LC cells. Conclusions: A new mechanism was uncovered that miR-106a-5p promotes LC development via AKTIP/PI3K/AKT/m-TOR axis, which guides clinical management and drug discovery.

Interaction of TLK1 and AKTIP as a Potential Regulator of AKT Activation in Castration-Resistant Prostate Cancer Progression.

Prostate cancer (PCa) progression is characterized by the emergence of resistance to androgen deprivation therapy (ADT). AKT/PKB has been directly implicated in PCa progression, often due to the loss of PTEN and activation of PI3K>PDK1>AKT signaling. However, the regulatory network of AKT remains incompletely defined. Here, we describe the functional significance of AKTIP in PCa cell growth. AKTIP, identified in an interactome analysis as a substrate of TLK1B (that itself is elevated following ADT), enhances the association of AKT with PDK1 and its phosphorylation at T308 and S473. The interaction between TLK1 and AKTIP led to AKTIP phosphorylation at T22 and S237. The inactivation of TLK1 led to reduced AKT phosphorylation, which was potentiated with AKTIP knockdown. The TLK1 inhibitor J54 inhibited the growth of the LNCaP cells attributed to reduced AKT activation. However, LNCaP cells that expressed constitutively active, membrane-enriched Myr-AKT (which is expected to be active, even in the absence of AKTIP) were also growth-inhibited with J54. This suggested that other pathways (like TLK1>NEK1>YAP) regulating proliferation are also suppressed and can mediate growth inhibition, despite compensation by Myr-AKT. Nonetheless, further investigation of the potential role of TLK1>AKTIP>AKT in suppressing apoptosis, and conversely its reversal with J54, is warranted.

Mice with reduced expression of the telomere-associated protein Ft1 develop p53-sensitive progeroid traits.

Human AKTIP and mouse Ft1 are orthologous ubiquitin E2 variant proteins involved in telomere maintenance and DNA replication. AKTIP also interacts with A- and B-type lamins. These features suggest that Ft1 may be implicated in aging regulatory pathways. Here, we show that cells derived from hypomorph Ft1 mutant (Ft1kof/kof ) mice exhibit telomeric defects and that Ft1kof/kof animals develop progeroid traits, including impaired growth, skeletal and skin defects, abnormal heart tissue, and sterility. We also demonstrate a genetic interaction between Ft1 and p53. The analysis of mice carrying mutations in both Ft1 and p53 (Ft1kof/kof ; p53ko/ko and Ft1kof/kof ; p53+/ko ) showed that reduction in p53 rescues the progeroid traits of Ft1 mutants, suggesting that they are at least in part caused by a p53-dependent DNA damage response. Conversely, Ft1 reduction alters lymphomagenesis in p53 mutant mice. These results identify Ft1 as a new player in the aging process and open the way to the analysis of its interactions with other progeria genes using the mouse model.

Lack of association between genetic polymorphism of FTO, AKT1 and AKTIP in childhood overweight and obesity / Falta de associação entre o polimorfismo genético do FTO, AKT1 e AKTIP e o sobrepeso e a obesidade infantis

Abstract Objective: Obesity is a chronic disease caused by both environmental and genetic factors. Epidemiological studies have documented that increased energy intake and sedentary lifestyle, as well as a genetic contribution, are forces behind the obesity epidemic. Knowledge about the interaction between genetic and environmental components can facilitate the choice of the most effective and specific measures for the prevention of obesity. The aim of this study was to assess the association between the FTO, AKT1, and AKTIP genes and childhood obesity and insulin resistance. Methods: This was a case-control study in which SNPs in the FTO (rs99396096), AKT1, and AKTIP genes were genotyped in groups of controls and obese/overweight children. The study included 195 obese/overweight children and 153 control subjects. Results: As expected, the obese/overweight group subjects had higher body mass index, higher fasting glucose, HOMA-IR index, total cholesterol, low-density lipoprotein, and triglycerides. However, no significant differences were observed in genes polymorphisms genotype or allele frequencies. Conclusion: The present results suggest that AKT1, FTO, and AKTIP polymorphisms were not associated with obesity/overweight in Brazilians children. Future studies on the genetics of obesity in Brazilian children and their environment interactions are needed.

Resumo Objetivo A obesidade é uma doença crônica sustentada por fatores ambientais e genéticos. Estudos epidemiológicos documentaram que maior ingestão de energia e um estilo de vida sedentário, bem como a contribuição genética, são forças por trás da epidemia de obesidade. O conhecimento sobre a interação entre os componentes genéticos e ambientais pode facilitar a escolha das medidas mais efetivas e específicas para a prevenção da obesidade. O objetivo deste estudo foi avaliar a relação entre os genes associado à massa de gordura e à obesidade (FTO), homólogo 1 do oncogene viral v-akt de timoma murino (AKT1) e de ligação AKT1 (AKTIP) e a obesidade infantil e a resistência à insulina. Métodos Estudo de caso-controle no qual os polimorfismos de nucleotídeo simples (SNPs) nos genes FTO (rs99396096), AKT1 e AKTIP foram genotipados em grupos de controle e de crianças obesas/acima do peso. Foram recrutadas 195 crianças obesas/acima do peso e 153 indivíduos controle. Resultados Como esperado, os indivíduos do grupo obeso/acima do peso apresentaram maior índice de massa corporal, maior glicemia de jejum, índice do modelo de avaliação de homeostase (HOMA-IR), colesterol total, lipoproteína de baixa densidade e triglicerídeos. Contudo, não encontramos diferenças significativas no genótipo de polimorfismos gênicos ou nas frequências alélicas. Conclusão Nossos resultados sugerem que os polimorfismos AKT1, FTO e AKTIP não estavam associados à obesidade/sobrepeso em crianças brasileiras. São necessários estudos futuros sobre a genética da obesidade em crianças brasileiras e suas interações ambientais.

Lack of association between genetic polymorphism of FTO, AKT1 and AKTIP in childhood overweight and obesity.

OBJECTIVE: Obesity is a chronic disease caused by both environmental and genetic factors. Epidemiological studies have documented that increased energy intake and sedentary lifestyle, as well as a genetic contribution, are forces behind the obesity epidemic. Knowledge about the interaction between genetic and environmental components can facilitate the choice of the most effective and specific measures for the prevention of obesity. The aim of this study was to assess the association between the FTO, AKT1, and AKTIP genes and childhood obesity and insulin resistance. METHODS: This was a case-control study in which SNPs in the FTO (rs99396096), AKT1, and AKTIP genes were genotyped in groups of controls and obese/overweight children. The study included 195 obese/overweight children and 153 control subjects. RESULTS: As expected, the obese/overweight group subjects had higher body mass index, higher fasting glucose, HOMA-IR index, total cholesterol, low-density lipoprotein, and triglycerides. However, no significant differences were observed in genes polymorphisms genotype or allele frequencies. CONCLUSION: The present results suggest that AKT1, FTO, and AKTIP polymorphisms were not associated with obesity/overweight in Brazilians children. Future studies on the genetics of obesity in Brazilian children and their environment interactions are needed.

Role of G-quadruplex located at 5' end of mRNAs.

BACKGROUND: Secondary structures in 5' UTR of mRNAs play a critical role in regulating protein synthesis. Though studies have indicated the role of secondary structure G-quadruplex in translational regulation, position-specific effect of G-quadruplex in naturally occurring mRNAs is still not understood. As a pre-initiation complex recognises 5' cap of the mRNA and scans along the untranslated region (UTR) before initiating translation, the presence of G-quadruplex in 5' region may have a significant contribution in regulating translation. Here, we investigate the role of G-quadruplex located at the 5' end of an mRNA. METHODS: Biophysical characterisation of putative G-quadruplexes was performed using UV and CD spectroscopy. Functional implication of G-quadruplex in the context of their location was assessed in cellulo using qRT-PCR and dual luciferase assay system. RESULTS: PG4 sequences in 5' UTR of AKT interacting protein (AKTIP), cathepsin B (CTSB) and forkhead box E3 (FOXE3) mRNAs form G-quadruplex whereas it is unable to form G-quadruplex in apolipoprotein A-I binding protein (APOA1BP). Our results demonstrated diverse roles of G-quadruplex located at 5' end of mRNAs. Though G-quadruplex in AKTIP and CTSB mRNA act as inhibitory modules, it activates translation in FOXE3 mRNA. CONCLUSIONS: Our works suggests that G-quadruplex present at the 5' terminal of an mRNA behaves differently in a different gene context. It can activate or inhibit gene expression. GENERAL SIGNIFICANCE: This study demonstrated that it is difficult to predict the role of G-quadruplex on the basis of its position in 5' UTR. The neighbouring nucleotide sequence, the intracellular milieu and the interacting partners might render diverse functions to this secondary structure.

Genetic variant of AKT1 and AKTIP associated with late-onset depression in a Brazilian population.

OBJECTIVES: Examine the association between polymorphisms in the AKT1 and AKTIP genes and late-onset depression (LOD). Major depressive disorder is one of the most prevalent neuropsychiatric diseases. LOD is a disorder that starts after 65 years old. AKT1 is a downstream enzyme that has been implicated in the pathogenesis of neurotransmitter-related disorders, such as depression. The identification of a novel AKT1-binding protein (AKTIP) was pointed as an important new target. AKTIP binds directly to AKT1, enhancing the phosphorylation of regulatory sites, and this modulation are affected by AKT1 activation. The association of AKT1 and AKTIP polymorphisms with depressive symptoms was not investigated in LOD. DESIGN: Genotype tagSNPs in the AKT1 and AKTIP in LOD patients and controls. SETTINGS: An academic medical center. PARTICIPANTS: Sample composed by 190 outpatients with LOD and 77 healthy individuals. MEASURES: The participants were evaluated using Diagnostic and Statistical Manual IV criteria, MINI-PLUS and the Geriatric Depression Scale. RESULTS: Our findings suggested an association between the tagSNP rs3730358 homozygous A/A (p = 0.006) and LOD. A strong association of allele A and increased association for LOD was demonstrated with tagSNP rs3730358 (p-value = 0.003). LIMITATIONS: Limitation include composition of our control group, where the exclusion criteria generated a kind of super-healthy older group what might have produced a hidden stratification when compared with the LOD. CONCLUSION: This study is the first one to establish the association of the AKT1/AKTIP genes and LOD, and further studies are necessary to clarify the functional role of these proteins.