Objective To observe the expression of matrix metalloproteinase（MMP-2, MMP-9 and vascular endothelial growth factor (VEGF) in retinoblastoma (RB) and its relationship with the differentiation and optic nerve infiltration of RB.Methods Forty paraffin specimens of pathological confirmed RB were studied. They were divided into differentiated group (15 cases) and undifferentiated group (25 cases) , optic nerve infiltration group（13 cases） and without optic nerve infiltration group（27 cases）. The expression of MMP-2, MMP-9 and VEGF were detected by immunohistochemistry, their relationships with the differentiation and optic nerve infiltration were also analyzed.Results The positive rate of MMP-2, MMP-9 and VEGF expression in 40 RB cases were 52.5％，57.5％ and 72.5% respectively．The expression of MMP-2, MMP-9 and VEGF in the undifferentiated group were significantly higher than those in the differentiated group (chi;2=9.037, 9.253, 8.095; P＜0.05). The expression of MMP-2, MMP-9 and VEGF in RB with optic nerve infiltration group were significantly higher than those in RB without optic nerve infiltration group (chi;2=11.045,10.243, 8.956；P＜0.05). The expression of MMP-2，MMP-9 had a positive correlation with the expression of VEGF in RB (r=0.126,0.314；P＜0.05). Conclusions MMP-2, MMP-9 and VEGF expressed in RB tumor tissues. The expression of MMP-2, MMP-9 has a positive correlation with the expression of VEGF. The levels of MMP-2, MMP-9 and VEGF expression are related to optic nerve infiltration of RB cells.
Children with retinoblastoma (RB) typically survive their cancer due to advances in early diagnosis and treatment. Extraocular invasion and metastasis, and secondary malignant tumor carry a very high mortality rate. Prerequisites for metastasis include tumor initiating capacity, altered cellular adhesion and cell motility, resistance to extracellular death signals and disruption of the basement membrane and extracellular matrix. All those changes can be determined by the cell of origin and the genetic instability of the tumor, responding to the multiple layers of pressure such as hypoxia, from the tumor microenvironment or niche. The interaction between tumor cells and the tumor stroma is regulated by several metastasissuppressor proteins and microRNA. This knowledge has important implications for our understanding and the treatment of extraocular spreading of RB.
Objective To observe the expression of sperm protein (SP) 32/OY-TES-1 in retinoblastoma (RB).Methods Thirty paraffin specimens of pathologically confirmed RB eyeballs were investigated in this study. The SP32/OY-TES-1 mRNA expression of 15 RB tissues, 12 non-tumor retinal tissues and 22 normal eye tissues were detected by reverse transcription polymerase chain reaction (RT-PCR). The SP32/OY-TES-1 protein expression of 30 RB tissues and 24 normal retinal tissues were examined by immunohistochemistry. The relationship between SP32/OY-TES-1 mRNA, protein expression and age, gender, tumor size, tumor differentiation, clinical stage of RB children were analyzed. Results The expression rate of SP32/OY-TES-1 mRNA in RB tissues, non-tumor retinal tissues and normal eye tissues were 86.7%, 16.7% and 36.4% respectively. Compared the expression rate of SP32/OY-TES-1 mRNA in different gender (chi;2=0.744)，age（chi;2=1.178），clinical stage(chi;2=1.188)，tumor size (chi;2=0.216)，tumor differentiation(chi;2=1.885)，the differences were not statistically significant (P＞0.05). The expression rate of SP32/OY-TES-1 protein in RB tissues was 73.3% and no expression in normal retinal tissues. Compared the expression rate of SP32/OY-TE-1 protein in different gender (chi;2=1.000)，agewith le;two years and ＞two years（chi;2=0.403），tumor size (chi;2=2.274)，tumor differentiation(chi;2=0.138), the differences were not statistically significant (P＞0.05); but in clinical stage (chi;2=6.193)，with or without optic nerve infiltration (chi;2=4.535), the differences were statistically significant(P＜0.05). Conclusions SP32/OY-TES-1 is highly expressed in RB. The expression rate of SP32/OY-TES-1 is related to optic nerve infiltration and clinical stage of RB.
Objective To observe the microvessel density（MVD）and expression of vascular endothelial growth factor (VEGF) in retinoblastoma（RB）before and after comprehensive treatment and explore its clinical correlations with tumor infiltration and recurrence. Methods Sixty-one paraffin specimens of RB were divided into enucleation without comprehensive treatment group (untreated group，52 cases), planned enucleation before comprehensive treatment group (planned enucleation group，six cases) and tumor recurrence after comprehensive treatment group（recurrence group，three cases）. There were optic nerve invasion in 19 cases，no optic nerve infiltration in 33 cases. The MVD and VEGF expressions of 61 paraffin specimens were detected by streptavidin biotin-peroxidase (SP) immunohistochemistry with monoclonal antibody of CD34 and VEGF. Real time PCR was performed for the VEGF expression of planned enucleation group and recurrence group.Results In the untreated group，the MVD and VEGF expression of optic nerve infiltration cases were significantly higher than those of cases without optic nerve infiltration（t=-2.4685, P=0.017; chi;2=8.416 6，P=0.032 8）.Tumor microvessel regression, decreased MVD, occlusion and hyaline changes of blood vessels were observed in the planned enucleation group in the course of systemic chemotherapy. Many neovascularized capillaries and increased MVD were observed in tumor tissues of the recurrence group. The VEGF expression of planned enucleation group was lower than that in the recurrence group.Conclusions There was no significant difference on VEGF expression in RB between with and without comprehensive treatment. The increasing MVD and VEGF expression of cases without comprehensive treatment were related to the optic nerve infiltration. And the increasing MVD may also play an important role in RB recurrence after comprehensive treatment.
Objective To investigate the possible mechanism of arsenic trioxide (As2O3) inducing P16 gene demethylation and transcription regulation in the retinoblastoma (RB) Cell Line Y79． Methods The induced growth inhibition of Y79 cell was assayed by MTT; The DNA content of Y79 cell was analyzed by flow cytometry after being exposed to As2O3; the methylation status of the P16 gene in Y79 cell line before and after treatment with As2O3 was detected by the nestedmethylation specific PCR and DNA sequencing; the mRNA of P16,DNA methyltransferases (DNMT3A and 3B)gene were determined by RT-PCR． Results As2O3 was able to inhibit the growth of Y79 cell and increase the cell number in G0-G1 phase；P16 gene was not expressed in Y79 cell line and As2O3 can induce itrsquo;s mRNA expression；after 48 hour disposal of As2O3，the methylation levelof P16 gene was apparently attenuated in Y79 cell line,the expression of DNMT3A and DNMT3B was obviously down-regulated． Conclusions P16 gene is the hypermethylation in the retinoblastoma cell line Y79, and As2O3 can inhibite the methylation of P16 gene and upregulate the expression of p16 gene mRNA which inhibits the proliferation of Y79 cell by inducing the G0-G1 arrest, by inhibiting the expression of DNA methyltransferases.
Objective To investigate the relationship of the expression between heat shock protein (HSP) 70 and 90, and Survivin and its effects on the proliferative activity in retinoblastoma (RB) cells. Methods Expression of Survivin, HSP70 and 90, and Ki-67 in conventional paraffin samples from 43 patients with RB and 6 healthy people was detected by streptavidin-biotin peroxidase (SP) immunohistochemical method. Ki67 labeling index was used to evaluate the proliferative activity in RB. Results In 43 cases of RB, positive expression of HSP70 and 90 and Survivin was found in 28 (65.12%), 37 (86.05%) and 27 (62.79%) cases, respectively. None of the 6 normal retinal tissue expressed HSP70, HSP90 or Survivin. Positive expression of Survivin was more frequent in positive expressions of HSP90 than that in negative expressions of HSP90 (P＜0.05). Ki67 labeling index was higher in positive expressions of HSP90 and positive expressions of Survivin than that in their negative expressions respectively (P＜0.05). Meanwhile, higher Ki67 labeling index was found in positive HSP90Survivin expressions than that in negative HSP90Survivin expressions and those cases where only HSP90 or Survivin was found (P＜0.05). Expression of HSP70 did not correlate with that of Survivin, nor had any significant effect on Ki67 labeling index (P＞0.05). Expression of HSPs and Survivin and Ki67 labeling index did not correlate with histological types (P＞0.05). Conclusion Expression of HSP90 correlates with that of Survivin in RB. Co-existence of Survivin and HSP90 probably plays an important role in the genesis of RB.
The debate on the cell of origin of human retinoblastoma lasted for more than one century. In the recent issue of ldquo;cellrdquo;, David Cobrinikprime;s group shows that L/M cone precursors are the most likely answer as they have an intrinsic circuitry, including murine double minute 2 (MDM2), Nmyc, the nuclear receptors retinoid X receptor and thyroxine receptor 2, making them extremely sensitive to transformation following retinoblastoma gene inactivation.