| ObjectiveThe tyrosine phosphorylation and dephosphorrylation are the important parts in the process of signal transduction. Protein Tyrosine phosphatases (PTPs) is a kinase which dehposphorylate the tyrosine in phosphorylated signal molecules. The roles in signal transduction and cell function played by PTPs are the same important as PTKs.SHP-2 is a member of Protein Tyrosine Phosphatase family and aProtein Tyrosine phosphatases containing SH2 dormain. It was discovered respectively by several experimental groups in the90's last century through the clone methods, named as SHP-2, PTP1D, SH-PTP3, SH-PTP2 and Syp by different groups. SHP-2bindsf the tyrosine phosphoric acid protein by SH2 doman, leading to the activation of PTP enzyme, which mediates signal transduction as the downstream signal memberand involved in the control of cell proliferation , differentiation, migration and death . In recent years , some experimental study found that SHP-2 plays an important role in the related signal transduction of the development and growth of normal hematopoietic cells as well as the tumor cell's adherence and embryo cell's growth.The multitudinous researches indicated that, Shp-2 transductes the signal of multiplication to the downstream effect members and positively regulate the growth of the hematopoietic cell through two important signal pathways: PI-3K/Akt and the Ras/Erk passways. Because PI-3K/Akt signal pathway takes part in proliferation, survival and anti- apoptosis of tumor cell's, it is proved to play the vital roles in occurrences and developing process of many tumors.Phosphoinositide 3-kinase (PI-3K) is a heterodimers composed of 110kDa catalytic subunit and 85kDa regulator subunit, containing 2 SH2 and 1 SH3 dormain. PI-3K is related with the cell skeleton assembly, cell differentiation, the anti-accent perishes and the glucose absorption. Its downstream is Akt. PI-3K/Akt passway as one of the most important signal transduction passway in cells, plays an vital role in promoting proliferation and suppressing apoptosis activatee the downstream members, such as apoptosis-related protein , cyclin , etc. Through over activaton of PI-3K/Akt pathway can be caused by the genemutation of the molecules in PBK/Akt pathway or expanded upstream signals, resulting the abnormal cell survival and apoptosis with malignant transformation of normal cells. The recent years research discovered that the consistent activation of the PI-3K/Akt passway is playing the vital role in the development of leukmia. There is little report in China on roles of SHP-2 and PI-3K/Akt pathway in acute leukemia.To explore the expression of SHP-2 and its relationships with pi-3k/Akt in Acute Leukemia, the expressions of SHP-2, PI-3K, Akt in bone marrow mononuclear cells from untreated Acute Leukemia patients, AL-CR patients and control group were detected by immunocytochemical staining (S-P three-step method). Their function in the leukemogenesis and clinical significance were discussed.Material and method1. Patients: (1) De novo leukemia group: Samples from 58 cases of de novo acute leukemia were collected. Patients were 10～75 years (mean 35 years old) with 35 males and 23 females.Patients were divided into two groups:①Acute Myelogenous Leukemia (n=41), including M02 cases, M2 23 cases, M3 7 cases, M4 3 cases, M5 3 cases, M6 2 cases, M7 1 case;②Acute lymphocytic Leukemia (n=17): The acute leukemias were diagnosed according to French-American-British classification. (2) AL-CR group: bone marrow samples from patients (n=35) who reached CR after chemotherapy. It was further divided into AML-CR and ALL-CR. (3) The control group: Bone marrow samples from non-malignant hematologic diseases (n=16). All the samples were obtained from the patients treated in the Hemotologic Department of the First Affiliated Hospital of Zhengzhou University through April to December of 2006.2. Sample processing: bone marrow mononuclear cells were separated from 1ml bone marrow of untreated Acute Leukemia patients and control patients. The BMNC were load on slides and detected by immunocytochemical staining(S-P three-step method) for the expressions of SHP-2, and PI-3K, pAkt.3. Statistical analysis: The data were analyzed with Fisher's exact test and Spearman correlation using a software SPSS11.0 and the standard of statistic significance was established as a=0.05.Results1. The expression of SHP-2 in control group was dim or negative. The positive rate of SHP-2 in de novo AL was 84.5% as positively or strong positively expressed in cytoplasm with 82.9% in AML and 88.2% in ALL, respectively. There was no significance between the positive rate of AML and ALL (P>0.05). The positive rate of SHP-2 in AL-CR was 31.4% and 29.2% in AML-CR, 36.4% in ALL-CR. There was no significance between the positive rate of AML-CR and ALL-CR (P>0.05). The expression of SHP-2 in de novo AL was significantly higher than that in AL-CR and control (P<0.05). And the expression of SHP-2 in AML and ALL was significantly higher than that in AML-CR and ALL-CR, respectively (P<0.05).2. The expression of PI-3K in control group was weak or negative. The positive rate of PI-3K in de novo AL was 81.0% as positively or strong positively expressed in nuclear or cytoplasm with 80.5% in AML, 82.3 % in ALL. There was no significant difference between the positive rate in AML and in ALL (P>0.05). The positive rate of PI-3K in AL-CR was 48.6% with 45.8% in ALL-CR and 54.5% in AML-CR, respectively. There was no significant difference between the positive rate in AML-CR and in ALL-CR (P>0.05). The expression of PI-3K in de novo AL was significantly higher than that in AL-CR and control (P<0.05). The expression of PI-3K in AML and ALL was higher than that in AML-CR and ALL-CR, respectively (P<0.05).3. The expression of pAkt in control group was weak or negative. The positive rate of pAkt in initialed novo AL was 60.3% as positively or strong positively expressed in nuclear or cytoplasm with 58.5% in AML, 64.7% in ALL. There was no significant difference between the positive rate in AML and in ALL (P>0.05). The positive rate of pAkt in AL-CR was 42.9% and 45.5% in ALL-CR, 41.7% in AML-CR. There was no significant difference between the positive rate in AML-CR and in ALL-CR (P>0.05). The expression of pAkt in de novo AL was significantly higher than that in AL-CR and control (P<0.05). The expression of pAkt in AML and ALL was higher than that in AML-CR and ALL-CR, respectively (P<0.05).4. There was a positive correlation between PI-3K and pAkt expression (r=0.477, P <0.05).5. There was a positive correlation between SHP-2 and PI-3K (r=0.382, P <0.05).6. There were a positive correlation between the level of SHP-2 and WBC, and infiltration of diseases (P>0.05). There was no significant correlation between the protein level of SHP-2, PI-3K, pAkt and patient's age, sex.Conclusion1. Shp-2 and PI-3K, pAkt overexpressed widely in all subtype of acute leukemia cells;2 . There were a positive correlation between the protein level of SHP-2 and WBC, and infiltration of diseases3. Shp-2 and the PI-3K/Akt signal passway play important roles in the development of leukemia. They may be new targets to treat the leukemia in the future.
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