Age-specific prevalence of human papillomavirus and abnormal cytology at baseline in a diverse statewide prospective cohort of individuals undergoing cervical cancer screening in Mississippi.

BACKGROUND: Mississippi (MS) has among the highest rates of cervical cancer incidence and mortality in the United States, with disproportionately higher rates among Blacks compared to Whites. Here, we evaluate the prevalence of high-risk human papillomavirus (HPV) and abnormal cytology in a representative baseline sample from a diverse statewide cohort of individuals attending cervical screening in MS from the STRIDES Study (STudying Risk to Improve DisparitiES in cervical cancer). METHODS: We included individuals aged 21-65 years undergoing screening at the University of Mississippi Medical Center (UMMC) and the Mississippi State Department of Health (MSDH) from May to November 2018. We calculated age-specific HPV prevalence, overall and by partial HPV16/18 genotyping, and abnormal cytology by race. RESULTS: A total of 6871 individuals (mean age 35.7 years) were included. HPV prevalence was 25.6% and higher in Blacks (28.0%) compared to Whites (22.4%). HPV prevalence was significantly higher in Blacks aged 21-24 years (50.2%) and 30-34 years (30.2%) compared to Whites in the same age groups (32.1% and 20.7%; p < 0.0001, respectively). The prevalence of high-grade cytologic abnormalities, a cytologic sign of cervical precancer, peaked earlier in Blacks (ages 25-29) compared to Whites (35-39). For comparison, we also analyzed HPV prevalence data from the National Health and Nutrition Examination Survey (NHANES, 2013-2016) and observed similar racial differences in HPV prevalence among women aged 21-24 years. CONCLUSIONS: Our findings suggest that Blacks undergoing cervical cancer screening in MS have higher prevalence of other high-risk 12 HPV types at younger ages and experience an earlier peak of high-grade cytologic abnormalities compared to Whites.

STRIDES - STudying Risk to Improve DisparitiES in Cervical Cancer in Mississippi - Design and baseline results of a Statewide Cohort Study.

Cervical cancer rates in Mississippi are disproportionately high, particularly among Black individuals; yet, research in this population is lacking. We designed a statewide, racially diverse cohort of individuals undergoing cervical screening in Mississippi. Here, we report the baseline findings from this study. We included individuals aged 21 years and older undergoing cervical screening with cytology or cytology-human papillomavirus (HPV) co-testing at the Mississippi State Health Department (MSDH) and the University of Mississippi Medical Center (UMMC) (December 2017-May 2020). We collected discarded cytology specimens for future biomarker testing. Demographics and clinical results were abstracted from electronic medical records and evaluated using descriptive statistics and chi-square tests. A total of 24,796 individuals were included, with a median age of 34.8 years. The distribution of race in our cohort was 60.2% Black, 26.4% White, 7.5% other, and 5.9% missing. Approximately 15% had abnormal cytology and, among those who underwent co-testing at MSDH (n = 6,377), HPV positivity was 17.4% and did not vary significantly by race. Among HPV positives, Black individuals were significantly less likely to be HPV16/18 positive and more likely to be positive for other high-risk 12 HPV types compared to White individuals (20.5% vs. 27.9%, and 79.5% and 72.1%, respectively, p = 0.011). Our statewide cohort represents one of the largest racially diverse studies of cervical screening in the U.S. We show a high burden of abnormal cytology and HPV positivity, with significant racial differences in HPV genotype prevalence. Future studies will evaluate cervical precancer risk, HPV genotyping, and novel biomarkers in this population.

Racial differences in HPV type 16 prevalence in women with ASCUS of the uterine cervix.

BACKGROUND: Understanding racial influences on human papillomavirus (HPV) distribution in women with atypical squamous cells of undetermined significance (ASCUS) cytology via partial genotyping in a statewide population can inform HPV-based prevention efforts. METHODS: Women aged 21 to 65 years with any cytology result and partial HPV genotyping for ASCUS triage between January 1, 2014, and December 31, 2017, were included. All women attended a Mississippi State Department of Health clinic. Age, race, cytopathologic, and HPV data were extracted from the electronic health record and analyzed. Cytologic specimens were processed with ThinPrep and HPV testing with the Cobas 4800 assay. HPV genotypes were evaluated in hierarchical categories. Chi-square tests and multinomial logistic regression models evaluated associations between race and type prevalence. RESULTS: There were 43,106 women who underwent cervical cancer screening with cytology and ASCUS triage. Of these, 34,363 (80.2%) had normal cytology, 4672 (10.9%) had ASCUS, 2683 (6.3%) had a low-grade squamous intraepithelial lesion, and 633 (1.5%) had a high-grade squamous intraepithelial lesion. Blacks represented 69.3% of the sample and had a higher proportion of HPV-positive ASCUS (6.5%) in comparison with whites (5.6%). Blacks had significantly decreased odds of HPV-16 (odds ratio [OR], 0.66; 95% confidence interval [CI], 0.6-0.9; P = .002) and significantly increased odds for 12 other types (OR, 1.37; 95% CI, 1.2-1.5; P < .0001) in comparison with whites. CONCLUSIONS: In a diverse population, significant differences in HPV genotypes are shown by race. Importantly, blacks with ASCUS are less likely to be positive for HPV-16 in comparison with whites. Ongoing work is evaluating the individual genotype prevalence and genotype-specific risk of precancer by race.

Expression profiling of tubulin isotypes and microtubule-interacting proteins using real-time polymerase chain reaction.

Real-time polymerase chain reaction (PCR) has been used for quantification of intracellular mRNA levels in cell culture and tissue samples. It is an important tool for studying antimitotic drug effects on tubulin isotype and microtubule-interacting protein levels and for measuring differences in normal and tumor tissue samples that could have predictive or prognostic applications. Both quantitative and comparative methods are valuable approaches; however, the selection of either approach requires an understanding of their benefits and challenges. In this chapter, we provide detailed protocols for real-time PCR experiments, discuss issues to consider in selecting real-time PCR methodologies, and give examples utilizing either quantitative or comparative approaches.

Effect of noscapine and vincristine combination on demyelination and cell proliferation in vitro.

Peripheral neuropathy is a common, dose-limiting side effect of vincristine, a frontline therapy for acute lymphoblastic leukemia. Combination chemotherapy that reduces the neurotoxicity without compromising the efficacy of vincristine would improve patient outcomes. We performed in vitro studies using a combination of microtubule-binding antimitotics, noscapine and vincristine. In cell cultures containing neurons, astrocytes, and oligodendrocytes, vincristine caused demyelination as shown by transmission electron microscopy. A combination of vincristine and noscapine protected against demyelination. Human acute lymphoblastic and acute myelogenous leukemia cell lines CCRF-CEM and HL-60, respectively, were used to determine the antiproliferative effect of this novel drug combination. Vincristine and noscapine decreased cell proliferation with IC(50) concentrations of 1 nM and 20 microM, respectively. Analysis of dose-effect relationships using isobolograms and combination indices demonstrated that noscapine acts synergistically with vincristine. Thus, noscapine is a promising candidate for use with vincristine to decrease neurotoxicity and enhance antineoplastic effectiveness.

Beta-tubulin isotype classes II and V expression patterns in nonsmall cell lung carcinomas.

Previous studies suggest that beta-tubulin isotype protein levels could be useful as indicators of nonsmall cell lung cancer (NSCLC) aggressiveness. However, measurement of protein amounts in tissue samples by staining techniques is semiquantitative at best. Since technologies for measuring mRNA levels have become more efficient and quantitative, we wanted to determine whether beta-tubulin message levels may be useful as biomarkers. Quantitative real-time RT-PCR was used to measure the seven classes of beta-tubulin isotypes, stathmin and MAP4 mRNA levels in 64 NSCLC and 12 normal lung tissue samples. We found significantly higher fractions of beta-tubulin classes II and V mRNA compared to the other isotypes in all lung tumor samples (P < 0.05). In addition, the ratio of beta-tubulin classes II/V mRNA was significantly higher in NSCLCs compared to normal lung tissues (P < 0.001). The data suggest that the ratio of beta-tubulin classes II and V mRNA could be useful as a biomarker for NSCLC tumor differentiation and/or NSCLC aggressiveness. Furthermore, the ratio of MAP4 to stathmin mRNA was found to be higher in diseased lung tissues compared to normal lung tissues, suggesting this ratio might also be used as a clinically relevant biomarker for NSCLCs.

Comparison of beta-tubulin mRNA and protein levels in 12 human cancer cell lines.

Antimitotic drugs are chemotherapeutic agents that bind tubulin and microtubules. Resistance to these drugs is a major clinical problem. One hypothesis is that the cellular composition of tubulin isotypes may predict the sensitivity of a tumor to antimitotics. Reliable and sensitive methods for measuring tubulin isotype levels in cells and tissues are needed to address this hypothesis. Quantitative measurements of tubulin isotypes have frequently relied upon inferring protein amounts from mRNA levels. To determine whether this approach is justified, protein and mRNA levels of beta-tubulin isotypes from 12 human cancer cell lines were measured. This work focused on only beta-tubulin isotypes because we had readily available monoclonal antibodies for quantitative immunoblots. The percentage of beta-tubulin isotype classes I, II, III, and IVa + IVb mRNA and protein were compared. For beta-tubulin class I that comprises >50% of the beta-tubulin protein in 10 of the 12 cell lines, there was good agreement between mRNA and protein percentages. Agreement between mRNA and protein was also found for beta-tubulin class III. For beta-tubulin classes IVa + IVb, we observed higher protein levels compared to mRNA levels.Beta-tubulin class II protein was found in only four cell lines and in very low abundance. We conclude that quantitative Western blotting is a reliable method for measuring tubulin isotype levels in human cancer cell lines. Inferring protein amounts from mRNA levels should be done with caution, since the correspondence is not one-to-one for all tubulin isotypes.

Beta class II tubulin predominates in normal and tumor breast tissues.

BACKGROUND: Antimitotic chemotherapeutic agents target tubulin, the major protein in mitotic spindles. Tubulin isotype composition is thought to be both diagnostic of tumor progression and a determinant of the cellular response to chemotherapy. This implies that there is a difference in isotype composition between normal and tumor tissues. METHODS: To determine whether such a difference occurs in breast tissues, total tubulin was fractionated from lysates of paired normal and tumor breast tissues, and the amounts of beta-tubulin classes I + IV, II, and III were measured by competitive enzyme-linked immunosorbent assay (ELISA). Only primary tumor tissues, before chemotherapy, were examined. Her2/neu protein amplification occurs in about 30% of breast tumors and is considered a marker for poor prognosis. To gain insight into whether tubulin isotype levels might be correlated with prognosis, ELISAs were used to quantify Her2/neu protein levels in these tissues. RESULTS: Beta-tubulin isotype distributions in normal and tumor breast tissues were similar. The most abundant beta-tubulin isotypes in these tissues were beta-tubulin classes II and I + IV. Her2/neu levels in tumor tissues were 5-30-fold those in normal tissues, although there was no correlation between the Her2/neu biomarker and tubulin isotype levels. CONCLUSION: These results suggest that tubulin isotype levels, alone or in combination with Her2/neu protein levels, might not be diagnostic of tumorigenesis in breast cancer. However, the presence of a broad distribution of these tubulin isotypes (for example, 40-75% beta-tubulin class II) in breast tissue, in conjunction with other factors, might still be relevant to disease progression and cellular response to antimitotic drugs.