Anomalous staged hot-electron acceleration by two-plasmon decay instability in magnetized plasmas

We present a staged hot-electron acceleration mechanism of the two-plasmon decay (TPD) instability in the transverse magnetic field under the parameters relevant to inertial confinement fusion experiments. After being accelerated by the forward electron plasma wave (FEPW) of TPD, the hot-electrons can be anomalously accelerated again by the backward electron plasma wave (BEPW) of TPD and then obtain higher energy. Moreover, the surfatron acceleration mechanism of TPD in the magnetic field is also confirmed, the electrons trapped by the TPD daughter EPWs are accelerated in the direction along the wave front. Interestingly, the velocity of electrons accelerated by surfing from the FEPW is quite easily close to the BEPW phase velocity, which markedly enhances the efficiency of the staged acceleration. The coexistence of these two acceleration mechanisms leads to a significant increase of energetic electrons generated by TPD in the magnetic field. Meanwhile the EPWs are dissipated, TPD instability is effectively suppressed, and the laser transmission increases.

Kinetic model and Vlasov simulation verification of two-ion decay instability

A kinetic theory is developed to describe the longitudinal decay of two-ion decay (TID): The pump ion-acoustic wave (IAW) decays into two daughter IAWs with a longer wavelength. The instability growth rate and threshold are given by the theory. Both the simulations of full kinetic Vlasov and hybrid Vlasov (kinetic ions and Boltzmann electrons) are employed to verify the theory and have a high quantitative agreement with the theory for 8≤ZT_{e}/T_{i}≤15, where Z is the ion charge number and T_{i}(T_{e}) is the ion (electron) temperature. The kinetic model developed here solves a long-standing problem that the simple fluid theory underestimates growth rate by a factor of 2∼3. Also, a reasonable explanation is given to the typical characteristics of TID that the dependence curves of subharmonic growth rate γ and wave number k.

Enhanced strong-coupling stimulated Brillouin amplification assisted by Raman amplification

Higher intensity of strong-coupling stimulated Brillouin scattering (SC-SBS) amplification is achieved by supplementary Raman amplification. In this scheme, a Raman pump laser first amplifies the seed pulse in the homogeneous plasma, and then a SC-SBS pump laser continues the amplification in the inhomogeneous plasma in order to suppress the spontaneous instability of pump lasers. The intensity of the seed laser gets higher and the duration of the seed laser gets shorter than that in the pure SC-SBS scheme with the same incident energy, while the energy conversion efficiency is not significantly reduced. We also found that the SC-SBS amplification is seeded by the leading pulse of Raman amplification. The results obtained from envelope coupling equations, Vlasov simulations, and two-dimensional particle-in-cell simulations agree with each other. This scheme offers a possible way to improve the SC-SBS amplification in experiments.

Suprathermal electrons from the anti-Stokes Langmuir decay instability cascade

The study of parametric instabilities has played a crucial role in understanding energy transfer to plasma and, with that, the development of key applications such as inertial confinement fusion. When the densities are between 0.11n_{c}≲n_{e}≲0.14n_{c} and the electron temperature is in inertial confinement fusion-relevant temperatures, anomalous hot electrons with kinetic energies above 100keV are generated. Here a new electron acceleration mechanism-the anti-Stokes Langmuir decay instability cascade of forward stimulated Raman scattering-is investigated. This mechanism potentially explains anomalous energetic electron generation in indirectly driven inertial confinement fusion experiments, it also provides a new way of accelerating electrons to higher energy for applications such as novel x-ray sources.

Polarization conversion in the caviton driven by linearly polarized lasers

In one-dimensional particle-in-cell simulations of a plasma irradiated by linearly polarized lasers from both sides of boundaries, it is found that there is an appreciable growth of the electromagnetic field in cavitons in the transverse direction perpendicular to the direction of polarization, which indicates the polarization conversion of the electromagnetic field in cavitons. This paper demonstrates the mechanism of this phenomenon based on parametric resonance induced by ponderomotive force with twice the frequency of the electromagnetic radiation in the caviton. We develop a theoretical model and verify it with simulation results. This phenomenon contributes to the heating and acceleration of particles and traps more EM energy in cavitons.

Early Death and Survival of Patients With Acute Promyelocytic Leukemia in ATRA Plus Arsenic Era: A Population-Based Study

Most randomized trials for acute promyelocytic leukemia (APL) have investigated highly selected patients under idealized conditions, and the findings need to be validated in the real world. We conducted a population-based study of all APL patients in Zhejiang Province, China, with a total population of 82 million people, to assess the generalization of all-trans retinoic acid (ATRA) and arsenic as front-line treatment. The outcomes of APL patients were also analyzed. Between January 2015 and December 2019, 1,233 eligible patients were included in the final analysis. The rate of ATRA and arsenic as front-line treatment increased steadily from 66.2% in 2015 to 83.3% in 2019, with no difference among the size of the center (≥5 or <5 patients per year, p = 0.12) or age (≥60 or <60 years, p = 0.35). The early death (ED) rate, defined as death within 30 days after diagnosis, was 8.2%, and the 3-year overall survival (OS) was 87.9% in the whole patient population. Age (≥60 years) and white blood cell count (>10 × 10⁹/L) were independent risk factors for ED and OS in the multivariate analysis. This population-based study showed that ATRA and arsenic as front-line treatment are widely used under real-world conditions and yield a low ED rate and a high survival rate, which mimic the results from clinical trials, thereby supporting the wider application of APL guidelines in the future.

CAG regimen for refractory or relapsed adult T-cell acute lymphoblastic leukemia: A retrospective, multicenter, cohort study

Adult patients with relapsed or refractory T‐cell acute lymphoblastic leukemia (R/R‐T‐ALL) have extremely poor prognosis, representing an urgent unmet medical need. Finding an optimal salvage regimen to bridge transplantation is a priority. The CAG (cytarabine, aclarubicin, and G‐CSF) regimen was initially used by one group in China, showing unexpectedly promising results in 11 R/R‐T‐ALL patients. Here, we report the multicenter results of 41 patients who received the CAG regimen as salvage therapy. After one cycle of the CAG regimen, complete remission and partial remission were achieved in 33 (80.5%) and two (4.9%) patients, respectively. Failure to respond was observed in six patients (14.6%). Early T‐cell precursor (ETP) (n = 26) and non‐ETP (n = 15) patients had a similar CR rate (80.8% vs 80.0%, P = .95). Among 41 patients, allo‐HSCT was successfully performed in 27 (66%) patients (22 in CR and 5 in non‐CR). With a median follow‐up time of 12 months, the estimated 2‐year overall survival and event‐free survival were 68.8% (95% CI, 47.3%‐83.0%) and 56.5% (95% CI, 37.1%‐71.9%), respectively. The CAG regimen was well‐tolerated, and no early death occurred. Our multicenter results show that the CAG regimen is highly effective and safe, representing a novel choice for adult patients with R/R‐T‐ALL and providing a better bridge to transplantation.

[Combined anluohuaxianwan and entecavir treatment significantly improve the improvement rate of liver fibrosis in patients with chronic hepatitis B virus infection]

Objective: To explore the improvement rate of liver fibrosis in patients with chronic hepatitis B virus infection who received entecavir alone or in combination with anluohuaxianwan for 78 weeks. Methods: Patients with chronic HBV infection were randomly treated with entecavir alone or in combination with anluohuaxian for 78 weeks. Ishak fibrosis score was used for blind interpretation of liver biopsy specimens. The improvement in liver fibrosis condition before and after the treatment was compared. Student's t test and non-parametric test (Mann-Whitney U-Test and Kruskal-Wallis test) were used to analyze the measurement data. The categorical variables were analyzed by Chi-square test method and Spearman's rank correlation coefficient was used to test bivariate associations. Results: Liver fibrosis improvement rate after 78 weeks of treatment was 36.53% (80/219) and the progression rate was 23.29% (51/219). The improvement of liver fibrosis was associated to the degree of baseline fibrosis and treatment methods (P < 0.05). The improvement rate of hepatic fibrosis in patients treated with anluohuaxianwan combined with entecavir at baseline F < 3 (54.74%, 52/95) was significantly higher than that in patients treated only with entecavir (33.33%, 16/48), P = 0.016 and the progression rate of hepatic fibrosis (13.68%, 13/95) was lower than that in patients treated alone (18.75%, 9/48), P = 0.466. In patients with baseline F < 3, the proportion of patients with improved and stable liver fibrosis in the combined treatment group (68.1%, 32/47) was higher than that in the treatment group alone (51.7%, 15/29). Conclusion: Combined anluohuaxianwan and entecavir treatment can significantly improve the improvement rate of liver fibrosis in patients with chronic hepatitis B virus infection. Furthermore, it has the tendency to improve the stability rate and reduce the rate of progression of liver fibrosis.

[Prognostic significance of proteins expression by immunohistochemical method in diffuse large B cell lymphoma]

Objective: To analyze the prognostic significance of TP53, Bcl-2, Bcl-6, Myc proteins expression by immunohistochemical method (IHC) in diffuse large B cell Lymphoma (DLBCL) . Methods: Clinical and pathologic data of 223 patients with DLBCL hospitalized in Zhejiang First Hospital from March 2009 to June 2015 were retrospectively analyzed. Results: The 223 cases, a median age of 56 years old with a male predominance, had shown a 39.0% of TP53 positive expression, 38.6% of Myc, 69.1% of Bcl-2, 56.5% of Bcl-6, and 22.7% of Myc/Bcl-2 double expression. According to Hans' classification, 27.4% were GCB and 72.6% were non-GCB. With a median follow-up of 38 (2-97) months, the 3 and 5 years survival rates were 70% and 66% , respectively. By multivariate analysis, TP53 over-expression and Myc/Bcl-2 double expression were independently associated with poor outcomes. 3-year and 5-year overall survival were 59% and 57% for patients with TP53 positive, 77% and 71% for patients with TP53 negative expression. Patients with non-GCB subtype receiving chemotherapy combined with rituximab had a higher OS than those without rituximab. But rituximab did not improve the prognosis of patients with TP53 positive. Conclusion: Myc/Bcl-2 double expression and TP53 over-expression are poor prognosis for DLBCL patients. Patients with Myc/Bcl-2 double expression have shorter OS. Patients with non-GCB subtype who received chemotherapy combined with rituximab have a better OS than those without rituximab. But rituximab does not improve the prognosis of patients with TP53 positive.

[Clinical effect of vacuum sealing drainage in the treatment of complex fracture and dislocation of foot with severe soft tissue injury]

Objective: To observe the clinical effect of vacuum sealing drainage (VSD) in the treatment of complex fracture and dislocation of foot with severe soft tissue injury. Methods: From March 2012 to January 2015, a retrospective analysis of 108 cases of the foot closed complex fracture dislocation with severe soft tissue injury in Department of Foot and Ankle, the Second Hospital of Tangshan City, Tangshan.Injury mechanisms included press and crush injury, traffic accident.According to the operation the cases were divided into the VSD group (56 cases) and the control group (52 cases). The injury foot swelling after treated by open reduction and internal fixation or fusion joint fracture and dislocation. VSD technique was used to cover the wound and wound in group VSD. The wound was sutured, the sterile dressing was covered and the dressing was changed regularly in the control group. Results: Preoperative hospitalization time: 16 days in group VSD, 28 days in the control group; the total hospitalization time: 33 days in group VSD, 53 days in the control group; wound healing: 29 cases in VSD group, 12 cases in the control group; prolonged healing after dressing: 16 cases in VSD group, 13 cases in the control group; after skin grafting healing: 9 cases in VSD group, 17 cases in the control group; healed after flap transposition: 2 cases in VSD group and 10 cases in thecontrol group.The difference of the data of the two groups was statistically significant, P<0.05.Maryland foot score: 55-98 (average: 88.8, median: 91.5) points in VSD group, 38-97 (average: 84.85, median: 91) points in control group, compared with median by rank sum test, Z value: -2.755, the difference was statistically significant, P< 0.05.The late recovery effect rating: 39 casesexcellent, good 12 cases, can be 5 cases, no poor in VSD group, excellent 29 cases, good 8 cases, can be 11 cases, poor 4 cases in the the control group, the difference was statistically significant, P<0.05. Conclusion: VSD can shorten the preoperative waiting time and total hospitalization time, improve the wound healing rate directly, reduce the skin grafting and flap transfer replacement rate, reduce the secondary injury, increased fracture risk reduction and internal fixation, reduce joint fusion rate in the treatment of foot closed complex fracture and dislocation with severe soft tissue injury.

Modulation of neuronal dynamic range using two different adaptation mechanisms

The capability of neurons to discriminate between intensity of external stimulus is measured by its dynamic range. A larger dynamic range indicates a greater probability of neuronal survival. In this study, the potential roles of adaptation mechanisms (ion currents) in modulating neuronal dynamic range were numerically investigated. Based on the adaptive exponential integrate-and-fire model, which includes two different adaptation mechanisms, i.e. subthreshold and suprathreshold (spike-triggered) adaptation, our results reveal that the two adaptation mechanisms exhibit rather different roles in regulating neuronal dynamic range. Specifically, subthreshold adaptation acts as a negative factor that observably decreases the neuronal dynamic range, while suprathreshold adaptation has little influence on the neuronal dynamic range. Moreover, when stochastic noise was introduced into the adaptation mechanisms, the dynamic range was apparently enhanced, regardless of what state the neuron was in, e.g. adaptive or non-adaptive. Our model results suggested that the neuronal dynamic range can be differentially modulated by different adaptation mechanisms. Additionally, noise was a non-ignorable factor, which could effectively modulate the neuronal dynamic range.

[Clinical effect of double layer vacuum sealing drainage in the treatment of delayed severe infection after calcaneal fracture operation]

Objective: To observe the clinical effect of vacuum sealing drainage (VSD) technique and simple dressing change in the treatment of delayed severe infection after calcaneal fracture surgery. Methods: From August 2008 to July 2015 , 73 patients with delayed severe infection were treated after calcaneal fractures 3 months in Department of Foot and Ankle, the Second Hospital of Tangshan City, according to the treatment methods are divided into vacuum sealing drainage group of 38 cases, 35 cases of simple dressing group.Two groups of patients after regular wound debridement debridement and sterilization after vacuum sealing drainage group received double wound VSD dressing group received postoperative dressing, two groups of patients with sensitive antibiotics for treatment.Two groups of patients according to the frequency of dressing change, wound healing time, bacterial clearance time and healing time were compared in stage Ⅱ during the perioperative period. Results: Vacuum sealing drainage group: dressing: 7 times, the wound healing time was 27 days, bacterial culture negative for 8 days, the healing time of 13.5 days of perioperative period; treatment group: 34 times the number of dressing, wound healing time was 44 days, bacterial culture negative for 18 days, the healing time of 17 days of surgery period. Two groups of data were compared with the median, after the rank sum test, the difference was statistically significant (Z values were -6.670, -5.529, -5.011, -3.227, P<0.05). The vacuum sealing drainage group compared with conventional dressing group significantly reduced the number of dressing, wound healing time, healing time was significantly shortened bacterial clearance time and perioperative period Ⅱ. Conclusion: Double VSD is easy , safe and quick, short cure time, less pain, higher quality of late life advantages, compared with the traditional dressing treatment of calcaneal fractures of postoperative delayed severe infection, is a safe and effective method.

Fluid nonlinear frequency shift of nonlinear ion acoustic waves in multi-ion species plasmas in the small wave number region

The properties of the nonlinear frequency shift (NFS), especially the fluid NFS from the harmonic generation of the ion-acoustic wave (IAW) in multi-ion species plasmas, have been researched by Vlasov simulation. Pictures of the nonlinear frequency shift from harmonic generation and particle trapping are shown to explain the mechanism of NFS qualitatively. The theoretical model of the fluid NFS from harmonic generation in multi-ion species plasmas is given, and the results of Vlasov simulation are consistent with the theoretical result of multi-ion species plasmas. When the wave number kλ_{De} is small, such as kλ_{De}=0.1, the fluid NFS dominates in the total NFS and will reach as large as nearly 15% when the wave amplitude |eϕ/T_{e}|∼0.1, which indicates that in the condition of small kλ_{De}, the fluid NFS dominates in the saturation of stimulated Brillouin scattering, especially when the nonlinear IAW amplitude is large.

[The imaging analysis of the age-related changes on maxillary sinus]

Objective:The aim of this study is to investigate the age-related changes rules of maxillary sinus.Method:The 540 patients (1 080 sides) with normal data of deputy sinus in spiral CT were enrolled,including 270 cases of male and female,age from 7 to 81 years old.They are divided into 9 groups according to the age:Group A at the age of 7-12 years old,Group B at the age of 13-17,Group C at the age of 18-20 years old,Group D at the age of 21-24 years old,Group E at the age of 25-28 years,Group F at the age of 29-35 years old,Group G at the age of 36-40 years old,Group H at the age of 41-65 years old,and Group I is more than 65 years old.By the gender,the patients in each group was divided into male and female groups.There are 30 cases in each group(60 sides).The volumes and the three-dimensional diameters of the maxillary sinus were measured,and the coefficient of gasification of them were calculated.Result:The maxillary sinus volume and 3 D lines have almost the same change trend along with the age between the male and female group;From 7 to 20 ages,they are increased linearly,13 to 17 fastest-growing;18 to 20 years old reached to peak;declined slightly in 21-28 years old,29-35 a second growth peak,and 36 to 40 years old have fallen sharply,to reaching a steady state after 41 years old;The gasification coefficient has no difference among all groups.Conclusion:The volume changes with the age-related on maxillary sinus is in the adolescent stage.It reaches a steady state in the middle and old age stage,and gasification coefficient on maxillary sinus has no age-related changes among all groups.

Identification of a novel duplication mutation in the VHL gene in a large Chinese family with Von Hippel-Lindau (VHL) syndrome

Von Hippel-Lindau (VHL) syndrome is characterized by hemangioblastomas of the brain, spinal cord, and retina, renal cysts, clear cell renal cell carcinoma, and pheochromocytoma. VHL is caused by mutations in the VHL tumor suppressor gene. We attempted to detect mutation in the VHL gene in a 5-generation Chinese family with VHL. We identified a novel small duplication that altered the reading frame downstream and created a premature TGA stop signal, resulting in severely truncated pVHL30 (p.Gly114Serfs*50) and pVHL19 (p.Gly61Serfs*50). This change was predicted to be an elongin-binding domain deletion.

Novel and recurrent COL2A1 mutations in Chinese patients with spondyloepiphyseal dysplasia

Spondyloepiphyseal dysplasia (SED) is an autosomal dominant skeletal dysplasia characterized by short stature, abnormal epiphyses and flattened vertebral bodies. SED is mainly caused by mutations in the gene encoding the type II procollagen α-1 chain (COL2A1). We looked for mutations in COL2A1 in three unrelated Chinese families with SED. Putative mutations were confirmed by RFLP analysis. We identified three missense mutations (p.G504S, p.G801S and p.G1176V) located in the triple-helical domain; p.G801S and p.G1176V are novel mutations. The p.G504S mutation has been associated with diverse phenotypes in previous studies. Our study extends the mutation spectrum of SED and confirms a relationship between mutations in the COL2A1 gene and clinical findings of SED.

Combined genetic and imaging diagnosis for two large Chinese families affected with Pelizaeus-Merzbacher disease

Pelizaeus-Merzbacher disease (PMD) is a rare X-linked recessive disorder characterized by nystagmus, impaired motor development, ataxia, and progressive spasticity. Genetically defective or altered levels of proteolipid protein (PLP1) or gap-junction alpha protein 12 gene have been found to be a common cause. Here we report on two large Han Chinese families affected with this disease. The probands of both families had produced sons featuring cerebral palsy that had never been correctly diagnosed. PMD was suspected after careful analysis of family history and clinical features. Three rounds of molecular testing, including RT-PCR, genetics linkage and SRY sequence analyses, in combination with fetal ultrasound and magnetic resonance imaging, confirmed the diagnosis. In Family 1, in addition to two patients, three carriers were identified, including one who was not yet married. Genetic testing indicated that a fetus did not have the disease. A healthy girl was born later. In Family 2, two patients and two carriers were identified, while a fetus was genetically normal. A healthy girl was born later. We concluded that by combining genetic testing and imaging, awareness of the symptoms of PMD and understanding of its molecular biology, there is great benefit for families that are at risk for producing offspring affected with this severe disease.

Quantitative evaluation of viable tissue perfusion changes with contrast-enhanced greyscale ultrasound in a mouse hepatoma model following treatment with different doses of thalidomide

OBJECTIVE

This study aimed to quantify intratumoural viable tissue perfusion with contrast-enhanced greyscale ultrasound to evaluate tumour response to anti-angiogenic treatment.

METHODS

H22 hepatoma-bearing mice were treated with low-dose thalidomide (Group B), high-dose thalidomide (Group C) or 0.5% carboxylmethylcellulose (Group A). Contrast-enhanced greyscale ultrasound was performed after 7 days of treatments to evaluate the percentage of non-enhanced area for each tumour; regions of interest within the enhanced area were analysed offline to determine the area under the curve (AUC), maximum intensity (IMAX), perfusion index (PI), mean transit time (MTT), time to peak (TTP) and quality of fit (QOF). Immunohistochemical analysis was performed for evaluation of microvascular density (MVD).

RESULTS

The percentage of non-enhanced area was significantly larger in Group C than in Groups A and B (p<0.05); however, there was no significant difference between Groups A and B. Treatment with thalidomide resulted in a significant decrease in AUC, PI and IMAX compared with Group A (p<0.05). Immunohistochemistry showed significant decreases in MVD in Groups B and C compared with Group A (p<0.05); however, there was no significant difference in MVD between Groups B and C. MVD was positively correlated with IMAX (r = 0.419, p = 0.023) and PI (r = 0.455, p = 0.013).

CONCLUSION

Quantitatively analysing intratumoural viable tissue perfusion enables early evaluation of tumour response to anti-angiogenic therapy before apparent changes in tumour necrosis.

Identification of novel and recurrent mutations in the calcium binding type III repeats of cartilage oligomeric matrix protein in patients with pseudoachondroplasia

Pseudoachondroplasia is an autosomal dominant osteochondrodysplasia characterized by disproportionate short stature, joint laxity, and early onset osteoarthrosis. Pseudoachondroplasia is caused by mutations in the gene encoding cartilage oligomeric matrix protein (COMP). We looked for mutations in the COMP gene in three sporadic Chinese pseudoachondroplasia patients and identified two novel mutations, c.1189G>T (p.D397Y) and c.1220G>A (p.C407Y), and one recurrent mutation, c.1318G>C (p.G440R), in the calcium binding type III repeats of COMP. This study confirms the relationship between mutations of the COMP gene and clinical findings of pseudoachondroplasia; it also provides evidence for the importance of the calcium binding domains to the functioning of COMP.

[Expression and activity of membrane surface tissue factor in peripheral blood cells of patients with cerebral infarction]

This study was aimed to investigate the expression and activity of membrane surface tissue factor (TF) of monocytes and platelets in peripheral blood cells from patients with cerebral infarction and their clinical significance. The TF expressions in monocytes and platelets from 25 patients with cerebral infarction were detected by flow cytometry, the TF activity was detected by chromogenic reaction method, and compared with 24 normal people used as control. The results showed that the TF expressions of monocytes and platelets in peripheral blood cells from patients with cerebral infarction were significantly higher than that in normal controls (p<0.01), and TF activity was also higher in patients than that in controls (p<0.01). In conclusion, the expression and activity of membrane surface in patients with cerebral infarction were enhanced, the hematocyte-derived tissue factor as a trigger in coagulation pathway is involved in pathological thrombosis in patients with cerebral infarction.

All-trans-retinoic acid increased the expression of integrin alpha5beta1 and induced "anoikis" in SMMC-7721 hepatocarcinoma cell

It is extensively shown that integrin can regulate various cellular functions, including apoptosis, probably by contributing to signal transduction processes through interaction with extracellular matrix (ECM) proteins. In the present study, DNA flow cytometric analysis demonstrated that SMMC-7721 hepatocarcinoma cells treated with 80 microM all-trans-retinoic acid (atRA) showed an increased expression of the integrin alpha5beta1, which was associated with the growth inhibition of the cells. We found that atRA treated cells showed obvious apoptosis. Then, it was postulated that the enhanced content of integrin alpha5beta1 in the absence of ligation with fibronectin (Fn) would stop transducing survival signals, and lead to decreased cell growth and apoptosis. To elucidate this hypothesis, we cultured the atRA treated cell in L-poly-lysine-coated and Fn-coated flask, respectively. The results indicated that Fn binding prevented the cells from apoptosis induced by atRA, in contrast to L-poly-lysine binding. When the transfectant with enhanced expression of integrin alpha5beta1 at the same level of atRA treated cell was cultured in L-poly-lysine-coated flask, apoptosis was triggered. However, apoptotic cell was not detected when those cells were cultured in Fn-coated flask. Meanwhile, culturing the transfectant in the antibody (against integrin alpha5 subunit)-coated flask induced 18.33% of the cells into apoptosis, which is far more than the control group. Our study suggests that increased expression of integrin alpha5beta1 on the surface of SMMC 7721 hepatocarcinoma cell treated by atRA, when unbound to Fn, would stop transducing survival signals to lead to "anoikis", and can be reverted by the interaction of integrin alpha5beta1 with Fn.

Over expression of integrin alpha 5 beta 1 in human hepatocellular carcinoma cell line suppresses cell proliferation in vitro and tumorigenicity in nude mice

Integrin alpha 5 beta 1 and alpha 2 beta 1 are the major integrin receptors in human hepatocytes. However, in human hepatocellular carcinoma cells it was found that the expression of integrin alpha 5 beta 1 was decreased and another integrin alpha 6 beta 1 increased. In this study, the SMMC7721 human hepatocellular carcinoma cells cotransfected or singly transfected with integrin alpha 5 and/or beta 1 cDNAs were established, and designated alpha 5 beta 1.6-7721, alpha 5.3-7721, and beta 1.6-7721 cell lines, respectively. Transfection with cDNAs of integrin alpha 5 and beta 1 subunits resulted in the over expression of each integrin and modified biological properties, including a slowed growth rate, changes in the cell cycle from 15.5% of control cells in the G2/M phase to 12.1%, 9.6% and 9.4% in alpha 5.3-7721, beta 1.6-7721, alpha 5 beta 1.6-7721, respectively, and a decrease in the Cell Mitosis Index from 1.6 in controls to 0.96, 0.95, and 0.72, and 34%, 28% and 52% derived from colony forming ability, respectively. Tumorigenicity was also tested in nude mice with inoculation of cells subcutaneously. Tumor masses growing in nude mice following inoculation with beta 1.6-7721, and alpha 5 beta 1.6-7721 cells weighed only 52% or 31% those of control cells. These results indicated that deletion or low expression of integrin alpha 5 beta 1 may play an important role in the development of hepatocellular carcinoma. Therefore, induction of expression of the integrin alpha 5 beta 1 in malignant cells could be a potential means of treating hepatocellular carcinoma.