Proteases and HPV-Induced Carcinogenesis

Simple Summary

Human papillomavirus (HPV) infection is a sexually transmitted disease with high prevalence worldwide. Although most HPV infections do not lead to cancer, some HPV types are correlated with the majority of cervical cancers, and with some anogenital and oropharyngeal cancers. Moreover, enzymes known as proteases play an essential role in the pathogenic process in HPV-induced carcinogenesis. This review highlights the role of proteases and recent epidemiological data regarding HPV-dependent carcinogenesis.

Abstract

Persistent infection with Human papillomavirus (HPV) is the main etiologic factor for pre-malignant and malignant cervical lesions. Moreover, HPV is also associated with oropharynx and other anogenital carcinomas. Cancer-causing HPV viruses classified as group 1 carcinogens include 12 HPV types, with HPV 16 and 18 being the most prevalent. High-risk HPVs express two oncoproteins, E6 and E7, the products of which are responsible for the inhibition of p53 and pRB proteins, respectively, in human keratinocytes and cellular immortalization. p53 and pRB are pleiotropic proteins that regulate the activity of several signaling pathways and gene expression. Among the important factors that are augmented in HPV-mediated carcinogenesis, proteases not only control processes involved in cellular carcinogenesis but also control the microenvironment. For instance, genetic polymorphisms of matrix metalloproteinase 1 (MMP-1) are associated with carcinoma invasiveness. Similarly, the serine protease inhibitors hepatocyte growth factor activator inhibitor-1 (HAI-1) and -2 (HAI-2) have been identified as prognostic markers for HPV-dependent cervical carcinomas. This review highlights the most crucial mechanisms involved in HPV-dependent carcinogenesis, and includes a section on the proteolytic cascades that are important for the progression of this disease and their impact on patient health, treatment, and survival.

Modulation of the Host Nuclear Compartment by Trypanosoma cruzi Uncovers Effects on Host Transcription and Splicing Machinery

Host manipulation is a common strategy for invading pathogens. Trypanosoma cruzi, the causative agent of Chagas Disease, lives intracellularly within host cells. During infection, parasite-associated modifications occur to the host cell metabolism and morphology. However, little is known about the effect of T. cruzi infection on the host cell nucleus and nuclear functionality. Here, we show that T. cruzi can modulate host transcription and splicing machinery in non-professional phagocytic cells during infection. We found that T. cruzi regulates host RNA polymerase II (RNAPII) in a time-dependent manner, resulting in a drastic decrease in RNAPII activity. Furthermore, host cell ribonucleoproteins associated with mRNA transcription (hnRNPA1 and AB2) are downregulated concurrently. We reasoned that T. cruzi may hijack the host U2AF35 auxiliary factor, a key regulator for RNA processing, as a strategy to affect the splicing machinery activities directly. In support of our hypothesis, we carried out in vivo splicing assays using an adenovirus E1A pre-mRNA splicing reporter, showing that intracellular T. cruzi directly modulates the host cells by appropriating U2AF35. For the first time, our results provide evidence of a complex and intimate molecular relationship between T. cruzi and the host cell nucleus during infection.

Kallikrein 5 Inhibition by the Lympho-Epithelial Kazal-Type Related Inhibitor Hinders Matriptase-Dependent Carcinogenesis

Head and neck squamous cell carcinoma remains challenging to treat with no improvement in survival rates over the past 50 years. Thus, there is an urgent need to discover more reliable therapeutic targets and biomarkers for HNSCC. Matriptase, a type-II transmembrane serine protease, induces malignant transformation in epithelial stem cells through proteolytic activation of pro-HGF and PAR-2, triggering PI3K-AKT-mTOR and NFKB signaling. The serine protease inhibitor lympho-epithelial Kazal-type-related inhibitor (LEKTI) inhibits the matriptase-driven proteolytic pathway, directly blocking kallikreins in epithelial differentiation. Hence, we hypothesized LEKTI could inhibit matriptase-dependent squamous cell carcinogenesis, thus implicating kallikreins in this process. Double-transgenic mice with simultaneous expression of matriptase and LEKTI under the keratin-5 promoter showed a prominent rescue of K5-Matriptase^+/0 premalignant phenotype. Notably, in DMBA-induced SCC, heterotopic co-expression of LEKTI and matriptase delayed matriptase-driven tumor incidence and progression. Co-expression of LEKTI reverted altered Kallikrein-5 expression observed in the skin of K5-Matriptase^+/0 mice, indicating that matriptase-dependent proteolytic pathway inhibition by LEKTI occurs through kallikreins. Moreover, we showed that Kallikrein-5 is necessary for PAR-2-mediated IL-8 release, YAP1-TAZ/TEAD activation, and matriptase-mediated oral squamous cell carcinoma migration. Collectively, our data identify a third signaling pathway for matriptase-dependent carcinogenesis in vivo. These findings are critical for the identification of more reliable biomarkers and effective therapeutic targets in Head and Neck cancer.

Relative expression of KLK5 to LEKTI is associated with aggressiveness of oral squamous cell carcinoma

•

Approximately 650,000 people will be diagnosed this year with cancers of the oral cavity and pharynx worldwide.

•

The absence of biomarkers for the disease early detection contributes to the late diagnosis.

•

Despite some advances with regards to treatment, overall survival has not significantly improved in decades.

•

We have shown that increased relative mRNA expression of KLK5 to LEKTI is associated with disease’s poor outcome.

•

This work supports the relative expression of KLK5 to LEKTI as a valuable prognostic marker.

Background

Oral squamous cell carcinoma (OSCC) remains a challenging cancer to treat despite all the advances of the last 50 years. Kallikrein 5 (KLK5) is among the serine proteases implicated in OSCC development. However, whether the activity of KLK5 promotes carcinogenesis is still controversial. Moreover, knowledge regarding the role of the KLK5 cognate inhibitor, Lympho-Epithelial Kazal-Type related Inhibitor (LEKTI), in OSCC is scarce. We have, thus, sought to investigate the importance of KLK5 and LEKTI expression in premalignant and malignant lesions of the oral cavity.

Methods

KLK5 and LEKTI protein expression was evaluated in 301 human samples, which were comprised of non-malignant and malignant lesions of the oral cavity. Moreover, a bioinformatic analysis of the overall survival rate from 517 head and neck squamous cell carcinoma (HNSCC) samples was performed. Additionally, to mimic the uncovered KLK5 to serine peptidase inhibitor (SPINK5) imbalance, the KLK5 gene was abrogated in an OSCC cell line using CRISPR-Cas9 technology. The generated cell line was then used for in vivo and in vitro carcinogenesis related experiments.

Results

LEKTI was found to be statistically downregulated in OSCCs, with increased KLK5/SPINK5 mRNA ratio being associated with a shorter overall survival (p = 0.091). Indeed, disruption of KLK5 to SPINK5 balance through the generation of KLK5 null OSCC cells led to smaller xenografted tumors and statistically decreased proliferation rates following multiple time points of BrdU treatment in vitro.

Conclusion

The association of increased enzyme/inhibitor ratio with poor prognosis indicates KLK5 to SPINK5 relative expression as an important prognostic marker in OSCC.

Cyclic parenteral nutrition does not change the intestinal microbiota in patients with short bowel syndrome

PURPOSE: To characterize of the intestinal microbiota of patients with short bowel syndrome (SBS) admitted to the Metabolic Unit of a University Hospital. METHODS: Fecal samples were evaluated, and biochemical tests were conducted only in the case of SBS patients. The nutritional status was assessed via anthropometric measurements and evaluation of food intake by means of a food questionnaire. The pathogenic strains were detected with the aid of cultures and specific biochemical tests in aerobic medium, for determination of species belonging to the Family enterobacteriaceae. Anti-sera were applied to each isolated E. coli strain, for determination of their possible pathogenicity. Molecular methodology was employed for establishment of the intestinal bacterial microbiota profile RESULTS: A lower amount of microorganisms of the family enterobacteriaceae per gram of stool was observed in the case of patients with SBS. However, molecular analysis showed maintenance of the bacterial species ratio, which is equivalent to a healthy intestinal microbiota. CONCLUSION: Despite the massive removal of the small bowel, frequent use of antibiotics, immune system depression, presence of non-digested food in the gastrointestinal tract, and accelerated intestinal transit, the ratio between intestinal bacterial species remain similar to normality.