The optimal treatment of stage ⅢA-N2 non-small cell lung cancer （NSCLC） remains controversial. Resultsof primary surgery alone are not satisfied. Surgery after induction chemotherapy yields better outcomes compared to resectiononly which has been widely accepted. Randomized studies show induction chemotherapy followed by either radiotherapy or surgery have approximately equivalent survival outcomes，significant improved survival can be achieved by combined surgery in selected patients. Low-grade N2，effective response and mediastinal downstaging after induction therapy，and successful complete resection by lobectomy，are good indications of surgery. Ideal treatments are approached base on theheterogeneity of N2 . Patients with bulky or fixed N2 disease should be considered for radical chemo-radiotherapy，and surgeryshould be a part of multi-modality management for patients with non-fixed，non-bulky，single-zone N2 disease. Further randomized trials of surgery added to multi-modality management in patients with multi-zone N2 disease should be taken in order to establish possible subgroups of patients might be benefitted more from the addition of surgery.
Objective To analyze the changes of gene expression profiles during the process that human bonemarrow mesenchymal stem cells (hBMSCs) are induced to differentiate into cardiomyogenic cells with 5-azacytidine (5-aza). Methods hBMSCs were isolated from marrow of obsolete ribs and induced with 5-aza. Then immunocytochemicalstaining was used to detect the expressions of α-actin, cardiac troponin T (cTnT), and connexin 43, and the percentage ofcTnT positive cells was tested with flow cytometry. In the process of differentiation, variation of gene expression was screenedwith Genechi ps Operating System of human gene expression profiles. And the differentially expressed genes were functionallyanalyzed and hierarchical clustered. Results When BMSCs were induced in vitro with 5-aza, part of the cells turnedinto myogenic cells morphologically. Before induction, immunocytochemical staining for α-actin and cTnT showed sl ightpositive and for connexin 43 showed negative. While after 3 weeks of induction, immunocytochemical staining for α-actin,cTnT, and connexin 43 showed all positive. With flow cytometry, the percentage of cTnT positive cells was 7.43% ± 0.02%before induction, but it was 49.64% ± 0.05% after induction. During differentiation, 1 814 differentially expressed geneswere reported by gene chi ps. Of them, 647 genes were divided into 5 groups with hierarchical clustering. They had variousbiological functions, involving signal transduction, cell metabol ism, prol iferation, differentiation, development, andtopogenesis. Conclusion hBMSCs can differentiate into cardiomyogenic cells with the induction of 5-aza in vitro. Multi plegenes related with signal transduction, transcri ption, and growth factors are involved during this process.
Objective To review the research progress of the current methods of inducing bone marrow mesenchymal stem cells (BMSCs) to chondrogenic differentiation in vitro so as to provide references for researches in cartilage tissue engineering. Methods Various methods of inducing BMSCs differentiation into the chondrogenic l ineage in vitro inrecent years were extensively reviewed and analyzed. Results Adding exogenous growth factors is still the mainly methodof inducing BMSCs differentiation into the chondrogenic l ineage; among the members, transforming growth factor β (TGF-β) family is recognized as the most important chondrogenic induction factor. Other important inducing factors include various chemical factors, physical factors, transgenic methods, and the microenvironmental induction. But the problems of low inducing efficiency and unstable inducing effects still exist. Conclusion The progress of chondrogenic induction of BMSCs promotes its util ization in cartilage tissue engineering. Further researches are needed for establ ishing more efficient, simpler, and safer inducing methods.
Objective To solve the shortage of hepatocytes for l iver tissue engineering, to explore the possibil ity of prol iferation of rat bone marrow mesenchymal stem cells (BMSCs) and the feasibil ity of differentiation of BMSCs into hepatocyteswith a culture system containing cholestatic rat serum and hepatocyte growth factor (HGF) in vitro. Methods Myeloid cellsof femur and tibia were collected from the female healthy Wistar rats at the age of 6 weeks, the BMSCs were isolated, purified and identified. Normal and cholestatic rat serum were prepared from 40 healthy Wistar rats at the age of 12-14 weeks. The 3rd passage of BMSCs were harvested and added different cultures according to the following grouping: group A, DMEM plus 10%FBS; group B, hepatocyte growth medium (HGM) plus 5%FBS; group C, HGM plus 5% normal rat serum; group D, HGM plus 5% cholestatic rat serum; group E, HGM plus 5% cholestatic rat serum plus 25 μg/L HGF. The changes of cell morphology were observed, MTT assay was used to measure cell growth; the expression of alpha-fetoprotein (AFP) and cytokeratin 18 (CK18) were detected by immunocytochemistry; the glycogen deposit was examined by periodic acid-schiff (PAS) staining; and the urea content in culture supernatant was determined by glutamate dehydrogenase. Results Polygonal cells and binuclear cells were observed in groups D and E, while the shapes of cells in groups A, B, and C did not obviously change. The cell growth curve demonstrated that the speed of cells proliferation in group C was the fastest, the one in group B was the slowest; showing significant differences when compared with groups A, D, and E (P lt; 0.05). On the 7th day in groups D and E, the positive expressions of AFP and CK18 emerged, on the 14th day the positive expression of glycogen emerged. At the same period, the expression ratio was higherin group E than in group D (P lt; 0.05). The urea concentration increased gradually with induction time in groups D and E, the concentration was higher in group E than in group D (P lt; 0.05). No expressions of AFP, CK18, glycogen, and change of the urea concentration were observed in groups A, B, and C. Conclusion Normal rat serum can obviously promote the growth of BMSCs; cholestatic rat serum which promote the growth of BMSCs can induce to differentiate into hepatocyte; and a combination of cholestatic serum and HGF can increase the differentiation ratio.
Objective The biological treatment of intervertebral disc degeneration becomes a research hotspot in recentyears. It is necessary to find an effective approach to induce bone marrow mesenchymal stem cells (BMSCs) differentiate to disc cells which could make appl ication of cell transplantation as a treatment of intervertebral disc degeneration. To investigate the effects of the recombinant plasmid pcDNA3.1IE-SOX9Flag on differentiation of rabbit BMSCs into nucleus pulposus-l ike cells. Methods The eukaryotic expression vector of pcDNA3.1IE-SOX9Flag was constructed. Rabbit BMSCs were isolated and cultured from one-month-old New Zealand white rabbits and were induced into osteogenetic cells in the osteogenesis supplement medium; and the cell surface markers were detected by flow cytometry. The cells at the 3rd passage were randomly divided into 3 groups: in transfected group, the cells were transfected with recombinant plasmid pcDNA3.1IE-SOX9Flag; in negative control group, the cells were transfected with plasmid pcDNA3.1; and in blank control group, the cells were treated with the media without recombinant plasmid. After selected by G418 for 7 days, the cells were harvested and RT-PCR was employed to assay SOX9 mRNA and collagen type II gene (Col2al) mRNA expressions in BMSCs. The expression of SOX9 protein was assayed by Western blot and collagen type II expression was also observed by immunohistochemical staining. Results The SOX9 eukaryotic expression vector was constructed successfully. The BMSCs after 5 days of osteogenetic induction were positive for the alkal ine phosphatase staining. What was more, CD44 expression was positive but CD34 and CD45 expressions were negative. The transfection efficiency was 34.32% ± 1.75% at 72 hours after transfection. After 2 weeks of transfection, BMSCs turned to polygonal and ell iptical. And the cell prol iferation was gradually slow which was similar to the growth characteristic of nucleus pulposus cells. RT-PCR identification showed that SOX9 mRNA and Col2al mRNA expressions were positive in transfected group, and were negative in 2 control groups. Western blot detection showed that SOX9 protein expressed in transfected group but did not express in the control groups. At 2 weeks after transfection, the result of the immunohistochemicalstaining for collagen type II was positive in transfected group. Conclusion The recombinant plasmid pcDNA3.1IE-SOX9Flag can be successfully transfected into rabbit BMSCs, the transfected BMSCs can differentiate into nucleus pulposus-l ike cells, which lays a theoretical foundation for treatment of intervertebral disc degeneration with BMSCs transplantation.
Objective To investigate the feasibil ity of inducing canine BMSCs to differentiate into epithel ial cells in vitro with epithel ial cell conditioned medium (ECCM). Methods Five mL BMSCs were obtained from il iac spine of a healthy adult male canine with weighing 10 kg, and then isolated and cultured. The oral mucosa was harvested and cut into 4 mm × 4 mm after the submucosa tissue was el iminated; ECCM was prepared. BMSCs of the 2nd passage were cultured and divided into two groups, cultured in ECCM as experimental group and in L-DMEM as control group. The cell morphological characteristics were observed and the cell growth curves of two groups were drawn by the continual cell counting. The cells were identified by immunohistochemical staining through detecting cytokeratin 19 (CK-19) and anti-cytokeratin AE1/AE3 on the21st day of induction. The ultra-structure characteristics were observed under transmission electron microscope. Results The cells of two groups showed long-fusiform in shape and distributed uniformly under inverted phase contrast microscope. The cell growth curves of two groups presented S type. The cell growth curve of the experimental group was right shifted, showing cell prol iferation inhibition in ECCM. The result of immunohistochemical staining for CK-19 and anti-cytokeratin AE1/AE3 was positive in the experimental group, confirming the epithel ial phenotype of the cells; while the result was negative in the control group. The cells were characterized by tight junction under transmission electron microscope. Conclusion The canine ECCM can induce allogenic BMSCs to differentiate into epithel ial cells in vitro.
Objective To investigate the effect of various concentration of platelet-rich plasma (PRP) on osteogenic differentiation of rabbit skeletal muscle-derived stem cells (SMSCs) cultured in vitro. Methods Blood drawn from the central ear arteries of 9 one-year-old New Zealand white rabbits weighing 2.5-3.0 kg (male and female) was used to prepare PRP (Landesberg method). Full blood count and platelet count in PRP were tested. Soleus muscle of right hindl imb in rabbit was obtained and used to culture SMSCs in vitro. The cells at passage 3 were randomly divided into different groups: the experimental groups in which the cells were treated by conditioned culture media with various concentrations of autologousPRP (6.25%, 12.50%, 25.00%, 50.00%), and the control group in which the cells were treated with the media without PRP. At different time points after intervention, osteogenetic activity of the cells was detected by ALP staining observation, ALP activity detection was conducted, al izarin red staining for calcium nodules and immunofluorescence staining for osteocalcin were performed, and core binding factor α1 (Cbfα1) of osteogenic gene expression was tested by RT-PCR. Results The full blood PRP count and the platelet count in PRP was (3.06 ± 0.46) × 105/μL and (18.08 ± 2.10) × 105/μL, respectively. ALP staining: the cells in all the experimental groups were positive for the staining with many black sediment particles in cytoplasm; the cells in the control group were negative staining. ALP activity: all the experimental groups were higher than the control group (P lt; 0.05), the experimental group at 12.50% was superior to other experimental groups at each time point (P lt; 0.05). Al izarin red staining: at 14 days after culture, orange-red calcium nodules were evident in all the experimental groups; no orange-red calcium nodules were observed in the control group with a mineral ization rate of zero; there were significant difference between the experimental groups and the control group in terms of mineral ization rate (P lt; 0.05), the experimental group at 12.50% had a higher mineral ization rate than other experimental groups (P lt; 0.05). Immunofluorescence staining for osteocalcin: at 7 days after culture, the experimental groups were positive for the staining with yellow fluorescence in cytoplasm, and the result of the control group was negative. RT-PCR detection: no obvious changes of the gene expression were noted at 4, 12, and 24 hoursafter culture in the control group; the gene expression in all the experimental groups was significant superior to that of control group, especially at 12 hours, and the expression in the experimental group at 12.50% was the highest. Conclusion PRP can obviously promote the osteogenic differentiation of SMSCs cultured in vitro in a concentration-dependent manner, and the 12.50% is proved to be the ideal concentration.
Objective To investigate the effect of hepatocyte-l ike cells induced by CD34+ cells in vitro on the repair of the injured hepatic tissues of mice in vivo. Methods Mononuclear cells were isolated from umbil ical blood by density gradient centrifugation and enriched CD34+ cells were obtained. The cells were (1 × 105 cells/mL) cultured in serumfreemedium containing stem cell factor (SCF), hepatocyte growth factor (HGF), EGF, oncostatin M (OSM), bFGF (the concentration were 50, 20, 20, 10, 10 ng/mL respectively) in vitro for 10 days. Forty-eight 6-week-old female ICR mice werechosen to prepare l iver injury model by injecting carbon tetrachloride and 2-acetylamionoflu-orene. The mice were randomly divided into two groups (n=24 per group): the experimental group, the cultured cells were injected into the mice through the tail vein; the control group, the equivalent serum-free medium was injected. Six mice from each group were killed at 7, 14, 21, and 28 days after operation to receive HE staining, PCR gel electrophoresis, immunohistochemistry staining, and hepatic function detection. Results HE staining: the morphology of injured hepatic tissues in the control group recovered to normal 28 days after operation, while in the experimental group, it recovered to normal 14 days after operation. PCR gel electrophoresis and immunohistochemistry staining: the cells expressing human serum albumin were detected in the hepatic tissue of the experimental group at each time point after operation; while in the control group, no such cells were detected within 28 days after operation. Hepatic function detection: the activity of alanine aminitransperase in the control group recovered to normal 14 days after operation; the mean activity of aspartate aminotransferase of two groups failed to recover within 28 days. Conclusion The hepatocyte-l ike cells induced by CD34+ cells in vitro can promote the morphological and functional recovery of the injured hepatic tissue in mice. Moreover, it can be transformed into human-derived hepatic cells in l iver-injured mice.
Objective To explore the in vitrodifferentiation of the rat mesenchymal stem cells (MSCs ) into the skeletal muscle cells induced by the myoblast differentiation factor (MyoD) and 5-azacytidine. Methods The MSCs were taken from the rat bone marrow and the suspension of MSCs was made and cultured in the homeothermia incubator which contained 5% CO2at 37℃. The cells were observed under the inverted phase contrast microscope daily. The cells spreading all the bottom of the culture bottle were defined as onepassage. The differentiation of the 3rd passage of MSCs was induced by the combination of 5-azacytidine, MyoD, transforming growth factor β1, and the insulin like growth factor 1. Nine days after the induction, the induced MSCs were collected, which were analyzed with the MTT chromatometry, theflow cytometry, and the immunohistochemistry. Results The primarily cultured MSCs grew as a colony on the walls of the culture bottle; after the culture for 5-7 days, the cells were shaped like the fibroblasts, the big flat polygonal cells, the medium sized polygonal cells, and the small triangle cells; after the culture for 12 days, the cells were found to be fused, spreadingall over the bottle bottom, but MSCs were unchanged too much in shape. After the induction by 5-azacytidine, some of the cells died, and the cells grew slowly. However, after the culture for 7 days, the cells grew remarkably, the cell volume increased gradually in a form of ellipse, fusiform or irregularity. After theculture for 14 days, the proliferated fusiform cells began to increase in a great amount. After the culture for 18-22 days, the myotubes increased in number and volume, with the nucleus increased in number, and the newly formed myotubes and the fusiform myoblst grew parallelly and separately. The immunohistochemistry for MSCs revealed that CD44 was positive in reaction, with the cytoplasm ina form of brown granules. And the nucleus had an obvious border，and CD34 was negative. The induced MSCs were found to be positive for desmin and specific myoglobulin of the skeletal muscle. The flow cytometry showed that most of the MSCs and the induced MSCs were in the stages of G0/G1，accounting for 79.4％ and 62.9％，respectively; however, the cells in the stages of G2/S accounted for 20.6％ and 36.1％. The growth curve was drawn based on MTT，which showed that MSCs weregreater in the growth speed than the induced MSCs. The two kinds of cells did not reach the platform stage，having a tendency to continuously proliferate.ConclusionIn vitro,the rat MSCs can be differentiated into the skeletal muscle cells with an induction by MyoD and 5-azacytidine, with a positive reaction for the desmin and the myoglobulin of the skeletal muscle. After the induction, the proliferation stage of MSCs can be increased, with a higher degree of the differentiation into the skeletal muscle.
Objective To explore the regulator factor of osteogenes is induced by the fibroblast in vitro so as to provide enough seeding cells for the bon e tissue engineering. Methods The fibroblasts were isolated and purified from granu lation of New Zealand rabbits, and they were incubated in the media offibronectin (FN) 10, 20, 40, 60 and 80 μg/ml, respectively, in the experimenta l grou ps 1- 5，but there was no FN in the control group. The markers for osteogenic features were investigated by fibroblast morphogenesis,calcium nodules formationratios,labeling of tetracycline fluorescence, labeling of 3H-TdR, determination of o steocaline, and labeling of 3H-proline within 2 weeks. Results The morphologic al changes of the fibroblasts were manifested as transference from a long spindle to a round or multiple form, shifted nucleus increased in number, confluenced and formed multilayered structure. There was a piling-up of calcium crystals that were gradually merged into foggy substances. The foggy substances increased and formed nodules. The calcium nodules formation ratios were as follows: 15.35％± 3.45％in the control group, and 53.73％± 9.49％, 75.21％± 9.80％, 98.34％± 15.2 0％, 61.83％± 10.04％, and 45.11％± 8.70％ in the experimental groups 1.5 ,respectively. There was a significant difference between the control group and the 5 experimental groups at 14 days (Plt;0.05), and a significant differenc e be tween the experimental group 3 and the other experimental groups at 14 days (Plt;0.05). The histochemical study on the nodules with the specific labeling of tet racycline fluorescence indicated that the nodules were composed of new bones. Conclusion Fibronectin can stimulate the fibroblast to prolifer ate, secrete osteocaline, and synthesize collagen fibrils. Fibronectin, in an optimal dose of 40 -60 μg/ml, is capable of inducing the fibroblast to form the bone.