Tera-1

Proteins and Parameters of HML.2 from Teratocarcinoma Cell Lines GH and Tera-1

Approximately 8% of our genome consists of sequences from Human Endogenous Retroviruses (HERVs). The HERV-K (HML.2) family, abbreviated here as HML.2, produces virus particles detected in cell lines, malignant tumors, and autoimmune diseases. Morozov et al. aim to characterize the virus proteins, estimate the buoyant density of viruses, and measure the RT activity of HML.2 GH and HML.2 Tera-1.

In order to facilitate the isolation of the viruses, GH and Tera-1 cells were cultivated in the normal medium without addition of any hormones or other stimulants. The supernatants of the cells were collected and processed the same day to prevent destruction of the virions. The virus pellets were diluted 2000 times and used for analysis in Western blot with anti-p27-CA serum (Fig. 1a). GH cells produced 4-5 times more Gag proteins compared to Tera-1 cells. HML.2 GH contained more unprocessed Pr76Gag, which may indicate impaired capsid maturation and Tera-1 had less unprocessed Gag precursors. Intermediate cleavage products of 50-42 kDa were present in both preparations, suggesting the presence of some virions with incompletely assembled capsids (Fig. 1a). To estimate viral buoyant density and to analyze the protein distribution, they performed sucrose density gradient centrifugation (Dgc). After Dgc, the fractions were collected, diluted in TN buffer, pelleted and used for analysis in Western blot (Fig. 1b, c). The majority of CA and TM proteins were found in fraction 4 (F4) with a buoyant density of 1.16 g/cm³. "Light" content, mainly Pr76Gag, was found in F3 (1.135 g/cm³) (Fig. 1b) which may be due to interaction with extracellular vesicles or low vRNA content.

VNC Drug Internalization of Tera-1 Cells

Vincristine (VNC), a powerful anticancer drug, faces challenges such as cytotoxicity and nonspecific distribution, leading to severe side effects. To address these issues, Al-Musawi et al. have explored using superparamagnetic iron oxide nanoparticles (SPIONs) encapsulated in dextran and conjugated with folate to deliver VNC specifically to cancer cells. They investigated the anticancer activity and molecular mechanisms of apoptosis induced by this novel polymeric-magnetic nanocarrier in Tera-1 testicular tumor cells.

In Tera-1 cancer cells, the introduced FA-DEX-VNC-SPION system was successfully internalized and it is clearly observed by fluorescence microscopy (Fig. 2B, C), while VNC was present in the form of crystal bodies of different sizes (Fig. 2A). The cells were treated with VNC-loaded nanocarriers and they were bright green because of the high internalization capacity. This finding was achieved due to the increasing solubility level of VNC after loading the nanocarrier. Green, star-like, and insoluble fragments were noticed in cells treated with VCN alone due to their insolubility in the aqueous medium. This finding clearly reveals that FA-DEX-VNC-SPION is a really powerful carrier which can be used as a delivery mechanism for drugs in Tera-1 cancer cell-targeted therapy. The results were considered satisfactory in the target applications and are in accordance with those previously reported.