Role of heat-shock proteins in infection of human adenocarcinoma cell line MCF-7 by tumor-adapted rotavirus isolates

Abstract

Background: Viruses are being used as alternative and complementary tools for treating cancers. Oncolytic viruses exhibit tumor tropism, ability to enhance anti-tumor immunity and ability to be used in combination with conventional chemotherapy and radiotherapy. We have recently selected some rotavirus isolates which are adapted to efficiently infect and kill tumor cell lines. Aim: We tested five tumor cell-adapted rotavirus isolates for their ability to infect the human adenocarcinoma cell line MCF-7. Methods: Cell surface membrane-associated proteins mediating virus particle attachment were characterized using ELISA, immunoprecipitation, FACS analysis, and antibody blocking. Results: It was found that heat shock proteins (HSPs) such as Hsp90, Hsp70, Hsp60, and Hsp40 are expressed on the cell surface forming complexes with protein disulfide isomerase (PDI), integrin β3, and heat shock cognate protein 70 (Hsc70) in lipid raft microdomains. Interaction of rotavirus isolates with these cellular proteins was further confirmed by a competition assay and an inhibition assay involving the HSPs tested. Conclusion: Our findings suggest that the tumor cell-adapted rotavirus isolates studied here offer a promising tool for killing tumor cells, thus encouraging further research into this topic, including animal models.

Preclinical evaluation of oncolytic potential human rotavirus Wt 1-5 in gastric adenocarcinoma

“…Here, using flow cytometry and epifluorescence analysis, we have found that gastric tumor cells express moderate to high levels of heat shock proteins (Hsp40, Hsp60, Hsp70, Hsp90, Hsc70), integrins (β1, β2, and β3), and protein disulfide isomerase (PDI and ERp57) on their surface, while all the proteins evaluated were expressed at low levels in adjacent non-tumor tissue. Pre-incubation of gastric tumor cells with antibodies directed against these proteins resulted in decreased rotavirus infection, validating their importance for the binding and entry of the rotavirus into tumor cells, as previously reported [ 17 , 20 ]. Interestingly, the gastric adenocarcinoma with the lowest expression of coreceptor proteins had the lowest percentage of infection at 12 h.p.i.…”

“…These mechanisms are favored by conformational changes that depend on thiol-disulfide exchanges by protein disulfide isomerase (PDI). It has been shown that the infective capacity of RV is reduced by blocking its union with antibodies directed against these proteins [15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”

“…This selectivity enables viral genes to be expressed, resulting in replication and subsequent lysis of the tumor cell [37]. Several cell surface proteins have been suggested to be involved in rotavirus entry into the host cell, such as Hsc70, integrins (αVβ3, α2β1, α4β1, and αxβ2), and protein disulfide isomerase (PDI) [17,20,22,24,25,27,35,[38][39][40].…”

HSP90 inhibitor NVP-HSP990 alleviates rotavirus infection

“…HSP90 promotes viral replication by regulating cell signaling systems or by direct interacting with viral proteins such as Hepatitis B virus reverse transcriptase, Hepatitis C virus non-structural protein 5A, and Influenza virus A RNA-dependent RNA polymerase (10)(11)(12)(13). HSP90 is involved in the entry of RV into certain tumor cell lines (14)(15)(16), and contributes to RV replication in vitro (17,18). Therefore, it seems that HSP90 inhibitors would be promising broad spectrum antiviral drug candidates (19); nevertheless, in contrast to the widespread application in anti-tumor therapies (20), no HSP90 inhibitors are in clinical use for antiviral therapies currently, probably due to unsatisfactory antiviral efficacy and undesirable toxicity.…”

“…Many studies revealed that HSP90 is enrolled in viral infections, i.e., HSP90 promotes viral replication either by regulating cell signaling systems or by direct interacting with viral proteins such as Hepatitis B virus (Hepatitis B, HBV) reverse transcriptase (10), Hepatitis C virus non-structural protein 5A (NS5A) (11), and Influenza virus A RNA-dependent RNA polymerase (12). In RV infection, HSP90 on cell surface participates in RV entry into some tumor cell lines including U937, MCF-7, and Reh cells (13)(14)(15); meanwhile, it was also reported that . CC-BY-NC 4.0 International license available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.…”