Forensic parameters and population structure based on 21 autosomal STRs with the investigator 24plex QS in mestizos from the Mexico City population.

Allele frequencies and forensic parameters for 21 STR autosomal markers (CSF1PO, D10S1248, D12S391, D13S317,D16S539, D18S51, D19S433, D1S1656,D21S11, D22S1045, D2S1338, D2S441, D3S1358, D5S818, D7S820, D8S1179, FGA, SE33, TH01, TPOX and vWA) were reported in 289 unrelated individuals from Mexico City, Mexico. In addition, an interpopulation analysis was performed including other world populations. In brief, the established population database of 21 autosomal STR markers in the present work is adequate for human identification purposes.

Sex differences in the influence of type 2 diabetes (T2D)-related genes, parental history of T2D, and obesity on T2D development: a case-control study.

BACKGROUND: This study investigated the effect of sex and age at type 2 diabetes (T2D) diagnosis on the influence of T2D-related genes, parental history of T2D, and obesity on T2D development. METHODS: In this case-control study, 1012 T2D cases and 1008 healthy subjects were selected from the Diabetes in Mexico Study database. Participants were stratified by sex and age at T2D diagnosis (early, ≤ 45 years; late, ≥ 46 years). Sixty-nine T2D-associated single nucleotide polymorphisms were explored and the percentage contribution (R2) of T2D-related genes, parental history of T2D, and obesity (body mass index [BMI] and waist-hip ratio [WHR]) on T2D development was calculated using univariate and multivariate logistic regression models. RESULTS: T2D-related genes influenced T2D development most in males who were diagnosed early (R2 = 23.5%; females, R2 = 13.5%; males and females diagnosed late, R2 = 11.9% and R2 = 7.3%, respectively). With an early diagnosis, insulin production-related genes were more influential in males (76.0% of R2) while peripheral insulin resistance-associated genes were more influential in females (52.3% of R2). With a late diagnosis, insulin production-related genes from chromosome region 11p15.5 notably influenced males while peripheral insulin resistance and genes associated with inflammation and other processes notably influenced females. Influence of parental history was higher among those diagnosed early (males, 19.9%; females, 17.5%) versus late (males, 6.4%; females, 5,3%). Unilateral maternal T2D history was more influential than paternal T2D history. BMI influenced T2D development for all, while WHR exclusively influenced males. CONCLUSIONS: The influence of T2D-related genes, maternal T2D history, and fat distribution on T2D development was greater in males than females.

The prevalence of diabetes worldwide is slightly higher in men than in women, particularly in those aged 50 or younger (16.5% for men versus 13.5% for women). This suggests that hormonal differences could be critical in early development of Type 2 diabetes. Some known factors previously associated with T2D, such as genes, parental history of diabetes and obesity, could have a differential influence between both sexes for the development of T2D. We compared these factors between 1008 healthy individual and 1012 TD2 patients. In this comparison, we calculated the percentage of variability of the disease explained by each factor. As expected, the most noticeable differences between men and women were observed in T2D diagnoses before age 46. Genes had a greater effect in men than in women (23.5% vs. 13.5%). While genes involved in insulin production have a greater influence on men, genes involved in peripheric insulin resistance have a greater influence on women. The overall parental history of T2D influences similarly in males (19.9%) and females (17.5%), however, the unilateral genetic influence of the mother was much greater in males than in females. The influence of global and abdominal obesity played a greater role in men than in women. In T2D diagnoses after age of 45, the influence of genes and parental history of diabetes decreases markedly, and the relative influence of global obesity augments. However, while genes linked to insulin resistance and inflammation predominate in females, genes linked to insulin secretion predominate in males.

Different Association of Human Papillomavirus 16 Variants with Early and Late Presentation of Cervical Cancer.

The median age of cervical cancer (CC) presentation coincides with the mean age of menopause presentation (49 years) in Mexico. Here, we investigated the association between different HPV16 variants and early (≤ 49 years) or delayed (≥ 50 years) CC presentation. We conducted a case-case study that included 462 CCs, 386 squamous cell carcinomas (SCC), 63 adenocarcinomas (ACC), and 13 additional cell types. Variants were identified by PCR and DNA sequencing. The risk conferred by each variant for developing CC earlier than 50 years was analyzed using a univariate logistic regression model considering old-aged patients (≥ 50 years) and non-HPV16 cases as the reference variables. Overall, the frequency of HPV16 was 50.9%, and the only identified variants were the European A1/2 (31.2%) and the Asian-American D2 (10.8%), and D3 (8.9%). D2 was mainly associated with ≤ 49-year-old patients (15.9%); A1/2 was uniformly distributed between the two age groups (~31%), whereas D3 increased with age to a frequency of 11.8% in the older group. Only the D2 variant conferred a 3.3-fold increase in the risk of developing CC before 50 years of age (OR = 3.3, 95% CI = 1.7-6.6, p < 0.001) in relation with non-HPV16 cases. Remarkably, this risk was higher for ACC (OR = 6.0, 95% CI = 1.1-33, p < 0.05) than for SCC (OR = 2.8, 95% CI = 1.3-5.9, p < 0.01). Interestingly, when analyzing only the HPV16-positive CC, D2 increases (OR = 2.5, 95% CI = 1.2-5, p < 0.05) and D3 decreases (OR = 0.45, 95% CI 0.2-0.9, p < 0.05) the risk to develop CC before 50 years old in relation with A1/2 variant. These results indicated that D2 variant is associated with early and D3 with delayed CC presentation, whereas A1/2 variant was uniformly distributed between the two age groups.

Genome Analysis of Latin American Cervical Cancer: Frequent Activation of the PIK3CA Pathway.

PURPOSE: Cervical cancer is one of the most common causes of cancer mortality for women living in poverty, causing more than 28,000 deaths annually in Latin America and 266,000 worldwide. To better understand the molecular basis of the disease, we ascertained blood and tumor samples from Guatemala and Venezuela and performed genomic characterization. EXPERIMENTAL DESIGN: We performed human papillomavirus (HPV) typing and identified somatically mutated genes using exome and ultra-deep targeted sequencing with confirmation in samples from Mexico. Copy number changes were also assessed in the exome sequence. RESULTS: Cervical cancer cases in Guatemala and Venezuela have an average age of diagnosis of 50 years and 5.6 children. Analysis of 675 tumors revealed activation of PIK3CA and other PI3K/AKT pathway genes in 31% of squamous carcinomas and 24% of adeno- and adenosquamous tumors, predominantly at two sites (E542K, E545K) in the helical domain of the PIK3CA gene. This distribution of PIK3CA mutations is distinct from most other cancer types and does not result in the in vitro phosphorylation of AKT. Somatic mutations were more frequent in squamous carcinomas diagnosed after the age of 50 years. Frequent gain of chromosome 3q was found, and low PIK3CA mutation fractions in many tumors suggest that PI3K mutation can be a late event in tumor progression. CONCLUSIONS: PI3K pathway mutation is important to cervical carcinogenesis in Latin America. Therapeutic agents that directly target PI3K could play a role in the therapy of this common malignancy.

The distribution of high-risk human papillomaviruses is different in young and old patients with cervical cancer.

Despite numerous human papillomavirus (HPV) frequency studies in women with cervical cancer (CC), little is known of HPV frequency trends according to patient age. In this work, we compare the mean age and frequency distribution by age of CC patients positive for different HPVs. This study included 462 CC patients. HPVs were detected by PCR and typed using DNA sequencing. A total of 456 patients (98.7%) were positive for HPV: 418 (90.5%) had single and 38 (8.2%) had double HPV infections. HPV16 (46.5%), HPV18 (10.4%), HPV45 (6.7%), and HPV31 (4.1%) were the most frequent viral types in single-infected patients. The mean ages of single-infected patients with HPV16 (49.2±13.3), HPV18 (47.9±12.2), HPV45 (47.9±11.7), or HPV39 (42.6±8.9) were significantly lower than the mean ages of patients singly (53.9±12.7; p<0.001, t-test) or doubly (55.4±12.7; p<0.05, t-test) infected with the remaining HPVs. Three different trends were identified: one for HPV16, another for HPVs18/45/39, and a third for the rest of HPVs. The frequency trend of HPV16 shows two peaks. The first (63.2%) was found in the youngest women (≤35 years), followed by a decreasing trend until the age of 55-60 years (31.1%). The second peak arose at 61-65 years (52.5%), followed by a decreasing trend. The trend for HPVs18/45/39 declined from the youngest (19.3%) to the oldest (>70 years; 12.8%) women. In contrast, the trend for the remaining HPVs increased from the youngest (15.8%) to the oldest (46.2%) women. Unlike other life-style factors, low-risk sexual behavior was associated with late onset of CC independent of low-oncogenic HPV types (p<0.05, Wald chi-square statistic). The data indicate that most CCs in young women depend on the presence of high-oncogenic HPVs. In contrast, almost half of CCs in older patients had low-oncogenic HPVs, suggesting they could depend on the presence of other factors.

Impact of gene dosage on gene expression, biological processes and survival in cervical cancer: a genome-wide follow-up study.

We investigated the role of tumor copy number (CN)-altered genome (CN-AG) in the carcinogenesis of cervical cancer (CC), especially its effect on gene expression, biological processes, and patient survival. Fifty-nine human papillomavirus 16 (HPV16)-positive CCs were investigated with microarrays-31 for mapping CN-AG and 55 for global gene expression, with 27 CCs in common. Five-year survival was investigated in 55 patients. Deletions and amplifications >2.5 Mb were defined as CN alterations. The %CN-AG varied from 0 to 32.2% (mean = 8.1±8.9). Tumors were classified as low (mean = 0.5±0.6, n = 11), medium (mean = 5.4±2.4, n = 10), or high (mean = 19.2±6.6, n = 10) CN. The highest %CN-AG was found in 3q, which contributed an average of 55% of all CN alterations. Genome-wide, only 5.3% of CN-altered genes were deregulated directly by gene dosage. In contrast, the rate in fully duplicated 3q was twice as high. Amplification of 3q explained 23.2% of deregulated genes in whole tumors (r2 = 0.232, p = 0.006; analysis of variance), including genes located in 3q and other chromosomes. A total of 862 genes were deregulated exclusively in high-CN tumors, but only 22.9% were CN altered. This suggests that the remaining genes are not deregulated directly by gene dosage, but by mechanisms induced in trans by CN-altered genes. Anaphase-promoting complex/cyclosome (APC/C)-dependent proteasome proteolysis, glycolysis, and apoptosis were upregulated, whereas cell adhesion and angiogenesis were downregulated exclusively in high-CN tumors. The high %CN-AG and upregulated gene expression profile of APC/C-dependent proteasome proteolysis were associated with poor patient survival (p<0.05, log-rank test). Along with glycolysis, they were linearly associated with FIGO stage (r>0.38, p<0.01, Spearman test). Therefore, inhibition of APC/C-dependent proteasome proteolysis and glycolysis could be useful for CC treatment. However, whether they are indispensable for tumor growth remains to be demonstrated.

Amplified genes may be overexpressed, unchanged, or downregulated in cervical cancer cell lines.

Several copy number-altered regions (CNAs) have been identified in the genome of cervical cancer, notably, amplifications of 3q and 5p. However, the contribution of copy-number alterations to cervical carcinogenesis is unresolved because genome-wide there exists a lack of correlation between copy-number alterations and gene expression. In this study, we investigated whether CNAs in the cell lines CaLo, CaSki, HeLa, and SiHa were associated with changes in gene expression. On average, 19.2% of the cell-line genomes had CNAs. However, only 2.4% comprised minimal recurrent regions (MRRs) common to all the cell lines. Whereas 3q had limited common gains (13%), 5p was entirely duplicated recurrently. Genome-wide, only 15.6% of genes located in CNAs changed gene expression; in contrast, the rate in MRRs was up to 3 times this. Chr 5p was confirmed entirely amplified by FISH; however, maximum 33.5% of the explored genes in 5p were deregulated. In 3q, this rate was 13.4%. Even in 3q26, which had 5 MRRs and 38.7% recurrently gained SNPs, the rate was only 15.1%. Interestingly, up to 19% of deregulated genes in 5p and 73% in 3q26 were downregulated, suggesting additional factors were involved in gene repression. The deregulated genes in 3q and 5p occurred in clusters, suggesting local chromatin factors may also influence gene expression. In regions amplified discontinuously, downregulated genes increased steadily as the number of amplified SNPs increased (p<0.01, Spearman's correlation). Therefore, partial gene amplification may function in silencing gene expression. Additional genes in 1q, 3q and 5p could be involved in cervical carcinogenesis, specifically in apoptosis. These include PARP1 in 1q, TNFSF10 and ECT2 in 3q and CLPTM1L, AHRR, PDCD6, and DAP in 5p. Overall, gene expression and copy-number profiles reveal factors other than gene dosage, like epigenetic or chromatin domains, may influence gene expression within the entirely amplified genome segments.

The Amerindian mtDNA haplogroup B2 enhances the risk of HPV for cervical cancer: de-regulation of mitochondrial genes may be involved.

Although human papillomavirus (HPV) infection is the main causal factor for cervical cancer (CC), there are data suggesting that genetic factors could modulate the risk for CC. Sibling studies suggest that maternally inherited factors could be involved in CC. To assess whether mitochondrial DNA (mtDNA) polymorphisms are associated to CC, HPV infection and HPV types, a case-control study was performed in the Mexican population. Polymorphism of mtDNA D-loop was investigated in 187 CC patients and 270 healthy controls. HPV was detected and typed in cervical scrapes. The expression of 29 mitochondrial genes was analyzed in a subset of 45 tumor biopsies using the expression microarray ST1.0. The Amerindian haplogroup B2 increased the risk for CC (odds ratio (OR)=1.6; 95% confidence interval (CI): 1.05-2.58) and enhanced 36% (OR=208; 95% CI: 25.2-1735.5) the risk conferred by the HPV alone (OR=152.9; 95% CI: 65.4-357.5). In cases, the distribution of HPV types was similar in all haplogroups but one (D1), in which is remarkable the absence of HPV18, a very low frequency of HPV16 and high frequencies of HPV45, HPV31 and other HPV types. Two mtDNA genes (mitochondrial aspartic acid tRNA (MT-TD), mitochondrial lysine tRNA (MT-TK)) could be involved in the increased risk conferred by the haplogroup B2, as they were upregulated exclusively in B2 tumors (P<0.01, t-test). Although the association of mtDNA with CC and HPV infection is clear, other studies with higher sample size will be needed to elucidate the role of mtDNA in cervical carcinogenesis.

A great diversity of Amerindian mitochondrial DNA ancestry is present in the Mexican mestizo population.

There are limited data on mitochondrial DNA (mtDNA) variation in the Mexican mestizo population. To examine the genetic diversity and matrilineal ancestry, the full mtDNA hypervariable regions I and II were sequenced in 270 unrelated mestizos from different regions of Mexico. A total of 202 different haplotypes were identified and the haplotype diversity was 0.9945. Amerindian haplotypes predominated in the sample with a proportion of 93.3%, followed by European (6.0%) and African haplotypes (0.7%). The frequency of the Amerindian haplogroups A2, B2, C1 and D1 was 51.1, 17.8, 18.5 and 5.9%, respectively. The frequency of Amerindian haplogroups was higher in the central region than in Mexico City, whereas it was the contrary for European haplogroups. This difference was accounted principally by the high frequency of B2 haplotypes in the central region. The minimum spanning network, the mismatch distribution and Tajima's D neutrality test suggest a population expansion for each Amerindian haplogroup, which could be initiated more recently for haplogroups A2 and D1. The present knowledge combined with other nuclear genetic markers will be essential in future association studies to correct for genetic substructure in mestizo populations.