Modulation effect of chromosome kinesin protein KIF4A on cisplatin resistance of A549/DDP cells / 国际生物医学工程杂志

Objective To investigate the process that chromosome kinesin KIF4A promote cisplatin resistance in lung cancer cells.Methods Reverse transcription PCR (RT-PCR) and Western Blot experiments were performed to analyze the expression of KIF4A in lung cancer cells A549 and cisplatin (DDP) resistant cells A549/ DDP.Cell transfection, RNA interference (RNAi) experiments and thiazolyl blue tetrazolium bromide (MTT) assays were carried out to examine cell proliferation of A549 cells with overexpression of exogenous KIF4A and A549/DDP cells with depletion of endogenous KIF4A after cisplatin treatment.Results Expression of KIF4A in A549/DDP cells was higher than that in A549 cells.With overexpression of exogenous KIF4A, A549 cells displayed drug resistance to cisplatin.On the contrary, depletion of endogenous KIF4A in A549/DDP cells resulted in cisplatin sensitivity.Conclusions Chromosome kinesin KIF4A involves in the regulation of cisplatin resistance in lung cancer cells and KIF4A may be a potential and effective new biological target for treatment of lung cancer cisplatin resistance.

An optimization technique to purify the pre-ribosome and ribosome from mammalian cells using continuous sucrose density gradient ultracentrifugation / 国际生物医学工程杂志

Objective To purify pre-ribosome and ribosome of mammalian ceils using continuous sucrose density gradient ultracentrifugation.Methods Continuous sucrose density gradient was established by ultracentrifugation,and the continuous sucrose density gradient of 10％-30％ and 10％-45％ were used to extract the pre-ribosome and ribosome in mammalian cells,respectively.The mammalian cell lysis buffer was added to the established continuous sucrose density gradient.Pre-ribosome and ribosome with different sedimentation coefficients were collected and the A260 absorbance of each sample was measured.Proteins of each sample were extracted to detect the large subunit protein,RPL15 by Western Blot.Results Large subunit ribosomal protein RPL15 exists on 60S of the pre-ribosome,and also on 60S,80S and polyribosome of mature ribosome.Conclusions The continuous sucrose density gradient,which is established by the swing-out rotor,can be used to isolate the pre-ribosome and ribosome of mammalian cells rapidly.This method has the advantages of good separation effect and simple operation,which provides a good method for rapid and large amount preparation and separation of various kinds of ribosomes.

Construction and identification of KIF18A protein baculovirus expression system / 国际生物医学工程杂志

Objective KIF18A is a protein that has close relation with mitotic regulation and tumor development.This study aimed to establish KIF18A protein expression system in baculovirus,which may help to realize high efficient synthesis of KIF1 8A protein in vitro.Methods Transfer vector was constructed with molecular cloning method,and recombinant baculovirus were obtained through gene transposition.KIF18A protein was expressed by transforming recombinant baculovirus into infected insect Sf-9 cells to realize the synthesis efficiency.Results It was confirmed by DNA sequencing,microscopic observation and Western Blot that the KIF18A protein expression system in baculovirus was successfully established.Conclusions Conditions for transfer vector and recombinant virus transfection are defined,and high efficient KIF18A protein baculovirus expression system are successfully constructed.