Original Article
STUDIES ON THE GAP JUNCTIONAL INTERCELLULAR COMMUNICATION OF HUMAN NASOPHARYNGEAL CARCINOMACELLS AND THE EFFECT OF RII
Abstract
Human nasopharyngeal carcinoma (NPC) cell line, CNE-2Z, and its clones (L2, H2, L4) with various invasive and metastatic potentials were examined for their gap junctions (GJ), gap junctional intercellular communication (GJIC) and the concentration of cytosolic free calcium ([Ca2+]i). Only a few intermediate junction (IJ) but no GJ structures were observed under electron microscope (EM). CNE-2Z cells showed marked JGIC, while its variants lacked this function using the scrapeloading dye-transfer technique (SLDT). There was lower concentration of [Ca2+]i in L2 cells (a variant with high invasive and metastatic potential) compared to that in H2 and L4 cells (variants with medium and low invasive and metastatic potentials, respectively). These data suggested that high invasive and metastatic potentials might be correlated with the level of [Ca2+]i in NPC cells.
The effect of RII (4-hydroxycarbophenyl retinamide) on NPC cells also investigated,. After 3-7 d of RII (10-5M) treatment, there was no change in the number of gap junctions and other kind of intercellular junctions in NPC cells observed under EM. The JGIC of CNE-2Z weaked and then disappeared finally with prolonging of RII treatment. However, there was no influence on its variants. The level of [Ca2+]i in NPC cells apparently fell after 6 h of RII treatment, and rose to original level with persisting of RII treatment. Whether the fluctuating of [Ca2+]i level is related to the inhibitory effect of RII treatment on growth and invasion of NPC cells needs to be further studied.
The effect of RII (4-hydroxycarbophenyl retinamide) on NPC cells also investigated,. After 3-7 d of RII (10-5M) treatment, there was no change in the number of gap junctions and other kind of intercellular junctions in NPC cells observed under EM. The JGIC of CNE-2Z weaked and then disappeared finally with prolonging of RII treatment. However, there was no influence on its variants. The level of [Ca2+]i in NPC cells apparently fell after 6 h of RII treatment, and rose to original level with persisting of RII treatment. Whether the fluctuating of [Ca2+]i level is related to the inhibitory effect of RII treatment on growth and invasion of NPC cells needs to be further studied.
