Study of Three Single Nucleotide Polymorphisms in the SLC6A14 Gene in Association with Male Infertility

Amino Acid Transporter SLC6A14 (ATB0,+) - A Target in Combined Anti-cancer Therapy

Cancer cells are characterized by quick growth and proliferation, demanding constant supply of various nutrients. Several plasma membrane transporters delivering such compounds are upregulated in cancer. Solute carrier family 6 member 14 (SLC6A14), known as amino acid transporter B^0,+ (ATB^0,+) transports all amino acids with exception of the acidic ones: aspartate and glutamate. Its malfunctioning is correlated with several pathological states and it is upregulated in solid tumors. The high expression of SLC6A14 is prognostic and unfavorable in pancreatic cancer, while in breast cancer it is expressed in estrogen receptor positive cells. As many plasma membrane transporters it resides in endoplasmic reticulum (ER) membrane after translation before further trafficking through Golgi to the cell surface. Transporter exit from ER is strictly controlled. The proper folding of SLC6A14 was shown to be controlled from the cytoplasmic side by heat shock proteins, further exit from ER and formation of coatomer II (COPII) coated vesicles depends on specific interaction with COPII cargo-recognizing subunit SEC24C, phosphorylated by kinase AKT. Inhibition of heat shock proteins, known to be upregulated in cancer, directs SLC6A14 to degradation. Targeting proteins regulating SLC6A14 trafficking is proposed as an additional pharmacological treatment of cancer.

Update on SLC6A14 in lung and gastrointestinal physiology and physiopathology: focus on cystic fibrosis

The solute carrier family 6 member 14 (SLC6A14) protein imports and concentrates all neutral amino acids as well as the two cationic acids lysine and arginine into the cytoplasm of different cell types. Primarily described as involved in several cancer and colonic diseases physiopathological mechanisms, the SLC6A14 gene has been more recently identified as a genetic modifier of cystic fibrosis (CF) disease severity. It was indeed shown to have a pleiotropic effect, modulating meconium ileus occurrence, lung disease severity, and precocity of P. aeruginosa airway infection. The biological mechanisms explaining the impact of SLC6A14 on intestinal and lung phenotypes of CF patients are starting to be elucidated. This review focuses on SLC6A14 in lung and gastrointestinal physiology and physiopathology, especially its involvement in the pathophysiology of CF disease.

Can uterine secretion of modified histones alter blastocyst implantation, embryo nutrition, and transgenerational phenotype?

Extracellular histones support rodent and human embryo development in at least two ways. First, these molecules in uterine secretions protect embryos from inflammation caused by pathogens that gain access to the reproductive tract. Also, histones in uterine secretions likely support penetration of the uterine epithelium by blastocysts during embryo implantation. Extracellular histones seem to preserve amino acid transport system B0,+ in blastocysts by inhibiting its activity. Preservation of system B0,+ is needed because, at the time of invasion of the uterine epithelium by motile trophoblasts, system B0,+ is likely reactivated to help remove tryptophan from the implantation chamber. If tryptophan is not removed, T-cells proliferate and reject the implanting blastocyst. Epigenetic modification of histones could alter their promotion of normal implantation through, say, incomplete tryptophan removal and, thus, allow partial T-cell rejection of the conceptus. Such partial rejection could impair placental development, embryonal/fetal nutrition, and weight gain prior to birth. Small-for-gestational-age offspring are predisposed to developing metabolic syndrome, obesity, and associated complications as adults. Shifting expression of these phenotypes might contribute to transgenerational variation and evolution. The spectrum of possible extracellular histone targets in early development warrant new research, especially since the effects of epigenetic histone modifications might be transgenerational.

Association of p53Pro72Arg (rs1042522) and MDM2309 (rs2279744) polymorphisms with risk for cervical intraepthelial lesions and cervical cancer development in Macedonian women

High risk Human Papillomavirus (HPV) is an important etiological factor in initiation of squamous intraepithelial lesions (SIL), but not enough for malignant progression to cervical cancer (CCa). Single nucleotide polymorphisms (SNPs): rs1042522 within the codon 72 of p53 and rs2279744 within MDM2 promoter gene are plausible factors for development of SIL or CCa conferring increased attenuation of p53 pathway. We investigated the association of these SNPs with the HPV positive SIL and CCa among women from the Republic of Macedonia. Using a multiplex PCR SNaPShot analysis we genotyped rs1042522 and rs2279744 in 131 HPV positive women with SIL or CCa and 110 HPV and cytologicaly negative controls subject. No significant difference in either genotype or allelic frequencies for rs1042522 and rs2279744 between cases and control was found. The stratification of patients on the basis of the lesion grade revealed lower frequency of CC genotype and C allele of rs1042522 in HSIL and CCa compared to LSIL [GG vs CC; p=0.001, OR=0.4; CG vs CC; p=0.04, OR=0.03 and CG+ GG vs CC; p=0.004, OR=0.2]. Additionally TT genotype and T allele of MDM2 309 showed significantly lower frequency in HSIL and CCa group then in LSIL [G vs T p=0.02, OR=0.52; GG vs TT; p=0.04, OR=0.29; ТТ vs ТG+GG; p=0.007, OR=0.34].The Arg variant of rs1042522 and T allele/TT genotype of rs2279744 are associated with progression to LSIL to HSIL or CCa and may be used as prediction markers in CCa management, but the clinical relevant warrants further validation in large and well-designed studies