Metabolic reprogramming is considered one of the hallmarks in cancer and is characterized by increased glycolysis and lactate production, even in the presence of oxygen, which leads the cancer cells to a process called “aerobic glycolysis” or “Warburg effect”. The E6 and E7 oncoproteins of human papillomavirus 16 (HPV 16) favor the Warburg effect through their interaction with a molecule that regulates cellular metabolism, such as p53, retinoblastoma protein (pRb), c-Myc, and hypoxia inducible factor 1α (HIF-1α). Besides, the impact of the E6 and E7 variants of HPV 16 on metabolic reprogramming through proteins such as HIF-1α may be related to their oncogenicity by favoring cellular metabolism modifications to satisfy the energy demands necessary for viral persistence and cancer development. This review will discuss the role of HPV 16 E6 and E7 variants in metabolic reprogramming and their contribution to developing and preserving the malignant phenotype of cancers associated with HPV 16 infection.

High-risk human papillomavirus (HPV) is the primary cause of cervical carcinoma (CC). Viral integration into the host chromosomes is associated with neoplastic progression, and epigenetic changes may occur as a result. The objective of the present study was to analyze HPV L1 gene methylation and to compare the use of quantitative polymerase chain reaction (qPCR), in situ hybridization (ISH) and L1 methylation analysis as methods for detecting HPV integration. Cervical scrapes or biopsy samples positive for HPV 16 or 18, from 187 female patients with CC, squamous intraepithelial lesions (SILs) or no intraepithelial lesion (non-IL) were analyzed. Methylation of the L1 gene was determined using bisulfite modification followed by PCR, and HPV integration was subsequently analyzed. HPV 16 L1 gene methylation was revealed to increase with histological grade, with statistically significant differences observed as follows: Low-grade SIL vs. CC, P<0.0001 and non-IL vs. CC, P<0.0001. HPV 18 L1 gene methylation also increased according to histological grade, however, no statistically significant differences were observed. Methylation at CpG site 5608 of the HPV 16 L1 gene was associated with all grades of cervical lesions, whereas methylation at CpG site 5617 demonstrated the strongest association with CC (odds ratio, 42.5; 95% confidence interval, 4.7–1861; P<0.0001). The concordance rates between the various methods for the detection of the physical status of HPV 16 and HPV 18 were 96.1% for qPCR and ISH, 76.7% for qPCR and L1 gene methylation, and 84.8% for ISH and L1 gene methylation. In conclusion, methylation of the HPV 16 L1 gene increases significantly according to the grade of the cervical lesion, and methylation at CpG sites 5608 and 5617 of this gene may be used as prognostic biomarkers. ISH and L1 gene methylation have good concordance with qPCR with regards to the detection of HPV integration. Therefore, these are useful methods in determining the physical state of HPV.

Metabolic reprogramming is typical in cancerous cells and is required for proliferation and cellular survival. In addition, oncoproteins of high-risk human papillomavirus (HR-HPV) are involved in this process. This study evaluated the relationship between glucose transporter I (GLUT1), lactate dehydrogenase A (LDHA), and monocarboxylate transporter type 4 (MCT4) expression and cervical intraepithelial neoplasia (CIN) and invasive cervical carcinoma (ICC) with HR-HPV infection. The protein expression was evaluated in women with CIN I ( n=20), CIN II/III ( n=16), or ICC ( n=24) by immunohistochemistry. The protein expression was analyzed qualitatively by van Zummeren score and quantitatively by Image ProPlus 6 software. LDHA expression increases in HPV-16 infection. In the CIN I group, GLUT1 immunostaining has a 35% protein expression at the membrane level at more than two thirds of the epithelium, which increased by 21.25% more in CIN II/III in more than two thirds of the epithelium. While LDHA and MCT4 in CIN I mostly do not present immunostaining, or this was only limited to the basal stratum, this expression is increased in CIN II/III and ICC cases. The GLUT1, LDHA, and MCT4 expression increased in ICC. The overexpression in high-grade CIN with HR-HPV infection shows a higher risk for cervical carcinoma progression.

Oxidative stress causes several chronic diseases including cancer. Some chemotherapeutic agents are not selective against tumor cells, causing oxidative stress in non-tumor cells. This study aimed to evaluate the cytotoxic effect of acetone extract of Ficus crocata(Miq.) Mart. ex Miq. (F. crocata) leaves (Ace-EFc) on cervical cancer cells, as well as its protective effect on hydrogen peroxide (H2O2)-induced lipoperoxidation and cytotoxicity in non-tumor HaCaT cells. Antioxidant activity was determined using the DPPH and ABTS radicals. Cell viability and lipoperoxidation were determined with MTT and 1-methyl-2-phenylindole assays, respectively. A model of H2O2-induced cytotoxicity and oxidative damage in HaCaT cells was established. HaCaT cells were exposed to the extract before or after exposure to H2O2, and oxidative damage and cell viability were evaluated. Ace-EFc inhibited the DPPH and ABTS radicals and showed a cytotoxic effect on SiHa and HeLa cells. Furthermore, the extract treatment had a protective effect on hydrogen peroxide-induced lipoperoxidation and cytotoxicity, avoiding the increase in MalonDiAldehyde (MDA) levels and the decrease in cell viability (p < 0.001). These results suggest that the metabolites of F. crocata leaves possess antioxidant and cytoprotective activity against oxidative damage. Thus, they could be useful for protecting cells from conditions that cause oxidative stress.

Background Cervical cancer (CC) is the fourth leading cause of death from neoplasms in women and is caused by the human papilloma virus (HPV). Several methods have been developed for the screening of cervical lesions and HPV; however, some socio-cultural factors prevent women from undergoing gynecological inspection, which results in a higher risk of mortality from cervical cancer in certain population groups as indigenous communities. This study aimed to compare the concordance in HPV detection from urine and cervical samples, to propose an alternative to cervical scraping, which is commonly used in the cervical cancer screening. Methodology The DNA from cervical scrapings and urine samples was extracted using the proteinase K method followed by precipitation with alcohol, phenol andchloroform; a modification of the proteinase K method was developed in the management of urine sediment. Viral genotyping was performed using INNOLipa. Results The study population consisted of 108 patients from an indigenous population at southern Mexico, 32 without squamous intraepithelial lesions (NSIL) and 76 with low squamous intraepithelial lesions (LSIL). The majority of NSIL cervical scrapes were negative for HPV (90.63%), whereas more than half of LSIL cases were high-risk HPV positive (51.32%), followed by multiple infection by HR-HPV (17.11%), and multiple infection by LR- and HR-HPV (9.21%). No statistically significant relationship between the cytological diagnosis and the HPV genotypes detected in the urine samples was observed. A concordance of 68.27% for HPV positivity from urine and cervical samples was observed. Similarly, a concordance of 64.52% was observed in the grouping of HPVs by oncogenic risk. HR-HPV was detected in 71% of the urine samples from women with LSIL diagnosis, which suggests that HR-HPV detected in a urine sample could indicate the presence or risk of developing SIL. Conclusion HR-HPV detection in urine samples could be an initial approach for women at risk of developing LSIL and who, for cultural reasons, refuse to undergo a gynecological inspection.