Hypomethylation at H19DMR in penile squamous cell carcinoma is not related to HPV infection

Penile squamous cell carcinoma (SCC) is a rare and aggressive tumour mainly related to lifestyle behaviour and human papillomavirus (HPV) infection. Environmentally induced loss of imprinting (LOI) at the H19 differentially methylated region (H19DMR) is associated with many cancers in the early events of tumorigenesis and may be involved in the pathogenesis of penile SCC. We sought to evaluate the DNA methylation pattern at H19DMR and its association with HPV infection in men with penile SCC by bisulfite sequencing (bis-seq). We observed an average methylation of 32.2% ± 11.6% at the H19DMR of penile SCC and did not observe an association between the p16INK4a+ (p = 0.59) and high-risk HPV+ (p = 0.338) markers with methylation level. The average methylation did not change according to HPV positive for p16INK4a+ or hrHPV+ (35.4% ± 10%) and negative for both markers (32.4% ± 10.1%) groups. As the region analysed has a binding site for the CTCF protein, the hypomethylation at the surrounding CpG sites might alter its insulator function. In addition, there was a positive correlation between intense polymorphonuclear cell infiltration and hypomethylation at H19DMR (p = 0.035). Here, we report that hypomethylation at H19DMR in penile SCC might contribute to tumour progression and aggressiveness regardless of HPV infection.

Long Non-coding RNAs and CRISPR-Cas Edition in Tumorigenesis

Long non-coding RNAs (lncRNAs) are one of the most abundant and heterogeneous transcripts with key roles in chromatin remodeling and gene regulation at the transcriptional and post-transcriptional levels. Due to their role in cell growth and differentiation, lncRNAs have emerged as an important biomarker in cancer diagnosis, prognosis, and targeted treatment. Recent studies have focused on elucidating lncRNA function during malignant transformation, tumor progression and drug resistance. The advent of the CRISPR system has made it possible to precisely edit complex genomic loci such as lncRNAs. Thus, we summarized the advances in CRISPR-Cas approaches for functional studies of lncRNAs including gene knockout, knockdown, overexpression and RNA targeting in tumorigenesis and drug resistance. Additionally, we highlighted the perspectives and potential applications of CRISPR approaches to treat cancer, as an emerging and promising target therapy.

HPV infection and 5mC/5hmC epigenetic markers in penile squamous cell carcinoma: new insights into prognostics

BACKGROUND

Penile cancer is one of the most aggressive male tumors. Although it is preventable, the main etiologic causes are lifestyle behaviors and viral infection, such as human papillomavirus (HPV). Long-term epigenetic changes due to environmental factors change cell fate and promote carcinogenesis, being an important marker of prognosis. We evaluated epidemiological aspects of penile squamous cell carcinoma (SCC) and the prevalence of HPV infection using high-risk HPV (hrHPV) and p16^INK4A expression of 224 participants. Global DNA methylation was evaluated through 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC).

RESULTS

The incidence of HPV was 53.2% for hrHPV and 22.32% for p16^INK4a. hrHPV was not related to systemic or lymph node metastasis and locoregional recurrence, nor influenced the survival rate. P16^INK4a seems to be a protective factor for death, which does not affect metastasis or tumor recurrence. Lymph node and systemic metastases and locoregional recurrence increase the risk of death. An increased 5mC mark was observed in penile SCC regardless of HPV infection. However, there is a reduction of the 5hmC mark for p16^INK4a + (P = 0.024). Increased 5mC/5hmC ratio (> 1) was observed in 94.2% of penile SCC, irrespective of HPV infection. Despite the increase in 5mC, it seems not to affect the survival rate (HR = 1.06; 95% CI 0.33-3.38).

CONCLUSIONS

P16^INK4a seems to be a good prognosis marker for penile SCC and the increase in 5mC, an epigenetic mark of genomic stability, may support tumor progression leading to poor prognosis.

In silico analysis of mismatches in RT-qPCR assays of 177 SARS-CoV-2 sequences from Brazil

INTRODUCTION:

Quantitative reverse transcription polymerase chain reaction (RT-qPCR) can detect the severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) in a highly specific manner. However, a decrease in the specificity of PCR assays for their targets may lead to false negative results.

METHODS:

Here, 177 high-coverage complete SARS-CoV-2 genome sequences from 13 Brazilian states were aligned with 15 WHO recommended PCR assays.

RESULTS:

Only 3 of the 15 completely aligned to all Brazilian sequences. Ten assays had mismatches in up to 3 sequences and two in many sequences.

CONCLUSION:

These results should be taken into consideration when using PCR-based diagnostics in Brazil.

P5329Montreal score and coronary artery calcification in the prediction of cardiovascular event in patients with familial hypercholesterolemia

Introduction

Familial hypercholesterolemia (FH) is characterized by elevated levels of LDL-C and early cardiovascular disease (CVD). However, the risk of CVD in HF is variable. The Montreal score was designed to stratify cardiovascular risk in the FH population. Coronary calcium score (CAC) is a tool that can be used to optimize CVD risk assessment in FH.

Purpose

The objective of this study is to evaluate whether CAC is superior to the Montreal score in cardiovascular risk discrimination in FH.

Methods

We Included 206 patients with molecular diagnosis of FH (36.4% men, mean age 45±14 years, mean baseline LDL-C: 269±70 mg/dL). All patients underwent CAC and were treated with maximum tolerated statin therapy. We evaluated cardiovascular risk factors and calculated Montreal score as prior publication. Cox regression analysis was performed to test the association of CAC with the incidence of cardiovascular events. CAC was transformed into LogCAC + 1 to optimize the distribution of the CAC as previously described. Area under the ROC curve was calculated for Montreal score and CAC.

Results

Patients were followed by a median of 3.7 years (interquartile range: 2.7 to 6.8 years). Mean Montreal score was 22±8, median of 22. CAC was positive in 105 individuals (51%) and 15 CVD events (7.2%) had occurred. Montreal score above the median was associated with CAC (OR: 8.36, 95% CI: 4.47–15.62, p<0.001), and there was a gradient of increase in the Montreal score with CAC increase (mean Montreal score for CAC = 0, CAC 1–100, CAC>100: 17±7, 23±7, 30±4, p<0.001). Univariate analysis showed that the following variables were associated with CVD occurrence: male gender, family history of early coronary disease, corneal arcus, HDL-c (protective), logCAC + 1 and Montreal score. Multivariate analysis was performed: model 1 with Montreal score and logCAC + 1, only logCAC + 1 was associated with the occurrence of CVD (RR: 3.886; 95% CI: 2.112–7.148, p<0.001). Model 2 with family history of early coronary disease, corneal arcus, logCAC + 1 and Montreal score, only the latter was not associated with the occurrence of CVD. CAC presents greater area under the ROC curve for CVD event discrimination compared to the Montreal score: 0.839 versus 0.685, p=0.0074.

Conclusion

The Montreal score is associated with CAC in FH, however CAC is superior than this clinical score in predicting the occurrence of CVD in FH.

Natural products as new antimitotic compounds for anticancer drug development

Cell cycle control genes are frequently mutated in cancer cells, which usually display higher rates of proliferation than normal cells. Dysregulated mitosis leads to genomic instability, which contributes to tumor progression and aggressiveness. Many drugs that disrupt mitosis have been studied because they induce cell cycle arrest and tumor cell death. These antitumor compounds are referred to as antimitotics. Vinca alkaloids and taxanes are natural products that target microtubules and inhibit mitosis, and their derivatives are among the most commonly used drugs in cancer therapy worldwide. However, severe adverse effects such as neuropathies are frequently observed during treatment with microtubule-targeting agents. Many efforts have been directed at developing improved antimitotics with increased specificity and decreased likelihood of inducing side effects. These new drugs generally target specific components of mitotic regulation that are mainly or exclusively expressed during cell division, such as kinases, motor proteins and multiprotein complexes. Such small molecules are now in preclinical studies and clinical trials, and many are products or derivatives from natural sources. In this review, we focused on the most promising targets for the development of antimitotics and discussed the advantages and disadvantages of these targets. We also highlighted the novel natural antimitotic agents under investigation by our research group, including combretastatins, withanolides and pterocarpans, which show the potential to circumvent the main issues in antimitotic therapy.