The role of KDELR1 and COPE genes in multiple myeloma pathogenesis

Multiple myeloma is the malignancy of terminally differentiated of plasma cells. It is taken place secondly within the hematological malignancy and characterized as proliferation of uncontrolled monoclonal plasma cells in bone marrow, accumulation of nonfunctional immunoglobins. In our previous experiment, we showed KDELR1 and COPE gene expression is increased in patients. Those are the genes taking place in transportation of protein between endoplasmic reticulum and golgi apparatus. KDELR1 makes the proteins with KDEL sequence bind. It plays role in packaging proteins into COPI vesicles to transport as retrograde. COPE gene is the epsilon subunit of COPI complex. In our experiment, KDELR1 expression was silenced in U266 and RPMI8226 cell lines to identify the role of its expression. Cells were scanned in confocal microscope to detect the apoptosis effects in control and KDELR1 siRNA applied groups. MTT test was applied to detect the effect of KDELR1 on cell proliferation. The effect of suppressed KDELR1 on COPE gene was identified by qRT-PCR. All experimental groups were studied during 24 and 48 hours. COPE gene expression difference was compared with the control. Although COPE gene expression in U266 was found dramatically increased in the 24th hour, any change wasn't observed in RPMI82226 cells. Apoptotic cell ratio in cells was found increased when compared with controls. Proliferation was decreased in both cells during 24th hours. Decreased cell proliferation effect was observed when KDELR1 was suppressed. This experiment is the first study showed the function of KDELR1 in the U266 and RPMI82266 cell lines.