RESUMO
Male primary adenocarcinoma of urethra is rare clinically. A patient with primary adenocarcinoma of posterior urethra complicated with intestinal metaplasia was admitted and underwent urethral mass resection. The tumor recurred 3 months after surgery and no further treatment was given for personal reasons. The purpose of this report is to improve clinicians' understanding of urethral cancer, so that patients can undergo more accurate diagnosis and treatment.
RESUMO
Objective To construct the recombinant yeast expressing PreS2 120-146-hepatitis B surface antigen (HBsAg),and to evaluate the immune effects of whole yeast cells.Methods PreS2 120-146 and HBsAg gene sequence were optimized according to the yeast cell codon preference,and were recombined and cloned into pPIC3.5K yeast expression vector to construct pPIC3.5K/PreS2 120-146 plasmid.After digested and linearized by Bgk Ⅱ restriction enzyme,pPIC3.5K/PreS2 120-146-HBsAg recombinant plasmid was electrotransformed into GS115 strain to screen PreS2 120-146-HBsAg-recombinant Pichiapastoris .The expression of PreS2 120-146-HBsAg was identified by sodium doclecyl sulfate polyacrylamide gel electrophogesis (SDS-PAGE),Western blot and enzyme linked immunosorbent assay (ELISA)analysis. BALB/c mice were vaccinated by inactivated whole recombinant yeast cells expressing target protein. Specific antibodies to HBsAg were detected by ELISA.Cytotoxic T lymphocyte (CTL)response induced by interferon (IFN)-γ was detected by reverse transcription-polymerase chain reaction (RT-PCR)when immune spleen cells of mice were stimulated by CTL epitope on HBsAg.Independent sample t test was used. Results Data of PCR detection,restriction enzyme digestion and sequencing analysis showed that recombinant pPIC3.5K/PreS2 120-146-HBsAg plasmid was successfully constructed.SDS-PAGE,Western blot and ELISA verified the expression of PreS2 120-146-HBsAg in the lysate of the recombinant Pichiapastoris induced by methanol.Levels of specific anti-HBsAg IgG antibodies produced by inactivated yeast cells vaccinated mice were comparable to purified HBsAg immunization (t =0.946,P =0.381 ). Analysis of HBsAg-specific CTL responses revealed that the level of IFN-γwas significantly higher when the immune spleen cells of mice were stimulated by CTL epitope peptides on HBsAg (t =2.305 ,P =0.044).Conclusions PreS2 120-146-HBsAg target protein is successfully expressed by construction of recombinant Pichiapastoris . The specific humoral and cellular immune responses are induced by recombinant whole yeast cells vaccinated mice.