Water-soluble Yb3+, Er3+ codoped NaYF4 nanoparticles induced SGC-7901 cell apoptosis through mitochondrial dysfunction and ROS-mediated ER stress

BACKGROUND

Nanoparticles are potential luminescent probes; among them, upconversion nanoparticles (UCNP) are currently being developed as fluorescent probes for biomedical applications. However, the molecular mechanisms of UCNP in human gastric cell lines remain poorly understood. Here, we aimed to examine UCNP cytotoxicity to SGC-7901 cells and explore its underlying mechanisms.

METHODS

The effects of 50-400 μg/mL UCNP on human gastric adenocarcinoma (SGC-7901) cells were investigated. Flow cytometry was used to evaluate reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), intracellular Ca²⁺ levels, and apoptosis. Activated caspase-3 and nine activities were measured; meanwhile, cytochrome C (Cyt C) in the cytosol and B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), protein kinase B (Akt), phosphorylated-Akt (p-Akt), 78 kDa glucose-regulated protein (GRP78), 94 kDa glucose-regulated protein (GRP94), calpain-1, and calpain-2 protein levels were also detected.

RESULTS

UCNP inhibited the viability of SGC-7901 cells in a concentration- and time-dependent manner and increased the proportion of cell apoptosis. Exposure to UCNP enhanced the ratio of Bax/Bcl-2, elevated the level of ROS, decreased ΔΨm, increased intracellular Ca²⁺ and Cyt C protein levels, decreased the levels of phosphorylated Akt, increased the activity of caspase-3 and caspase-9, and upregulated the protein expression of GRP-78, GRP-94, calpain-1 and calpain-2 in SGC-7901 cells.

CONCLUSION

UCNP induced SGC-7901 cell apoptosis by promoting mitochondrial dysfunction and ROS-mediated endoplasmic reticulum (ER) stress, initiating the caspase-9/caspase-3 cascade.

Human papillomavirus infection by anatomical site among Greek men and women: a systematic review

We systematically reviewed the literature on anal, penile, cervical, and oropharyngeal human papillomavirus (HPV) infection in Greece to provide a comprehensive overview of HPV prevalence and to explore the reporting of HPV in Greek men and women. A total of five databases, including PubMed and Scopus, were searched up until 1 January 2015 for studies looking at HPV prevalence, incidence, or risk factors by anatomical site. We identified 50 eligible studies for inclusion. The majority of them were cervical studies (n=26) followed by head and neck studies (n=13) with only two studies exclusively focusing on anal sites and two on penile sites. The remaining studies examined prevalence from multiple sites. Most studies looked at small, high-risk populations, and HPV prevalence ranged from 2.5-43.4% for cervical studies; 0-91% for head and neck studies; 54.6-78.4% for anal studies; and 20.3-66.7% for penile studies. Age, smoking, and number of sexual partners were the commonly assessed risk factors. There were significant sex and anatomic site disparities in the reporting of HPV prevalence. Given the relationship between HPV infection and the increasing incidence of anal cancer in men, more research is needed to reveal the prevalence of HPV at these sites in Greek men, especially given the reports of the declining health of the Greek population.

Oral Human Papillomavirus in Youth From the Pediatric HIV/AIDS Cohort Study

In contrast to high rates of oral human papillomavirus (HPV) found in human immunodeficiency virus (HIV)-infected adults, only 2% of 209 perinatally HIV-infected youth had oral HPV. This rate was similar in HIV-exposed but uninfected youth. No association was found with sexual activity; however, low CD4 counts were associated with oral HPV.

The paediatric story of human papillomavirus (Review)

Human papillomavirus (HPV) is composed of a particularly heterogeneous family of DNA viruses, which has gained much attention in recent years due to the discoveries of Professor Harald zur Hausen, who first identified a connection between HPV and cervical cancer. Professor Harald zur Hausen, the 'Father of HPV Virology', was the recipient of the 2008 Nobel Prize. HPV can be transmitted through physical contact via autoinoculation or fomites, sexual contact, as well as vertically from the HPV-positive mother to her newborn, causing subclinical or clinical infections. In infancy and childhood, HPV-associated clinical infections include skin warts, genital warts and juvenile recurrent respiratory papillomatosis, while cervical squamous intraepithelial lesions have also been reported among adolescent girls. To date, several research teams, worldwide, have extensively investigated HPV from the paediatric point of view. This primitive effort has been performed before the recent great expansion of paediatric HPV research due to the vaccination programmes against HPV, which were introduced into clinical practice in 2006. In this review article, we present a brief overview of paediatric HPV research after the first report in 1978 involving children in the research of HPV until the time point of this great expansion. In the future, it is expected that further unresolved issues will be addressed and clarified, as the paediatric story of HPV remains a challenging research target.

The ‘Trojan horse’ oncogenic strategy of HPVs in childhood

HPVs are considered to be the principal cause of cervical cancer worldwide. During the last decade, their possible oncogenic involvement has also been proposed in a substantial proportion of nongenital cancers, such as breast and lung cancer. The presence of high-risk HPVs in the neonatal oral mucosa supports the transmission of HPVs from the mother to her newborn. This review presents current evidence that supports the perinatal transmission of high-risk HPVs and suggests that this may be the initial step of the oncogenic strategy of high-risk HPVs in humans. The hypothesis that children are a unique reservoir of silent high-risk HPVs, analogously to the Trojan horse, should be investigated further.