Targeting tumor-intrinsic SLC16A3 to enhance anti-PD-1 efficacy via tumor immune microenvironment reprogramming.

Immunotherapy, especially immune checkpoint inhibitors, has revolutionized clinical practice within the last decade. However, primary and secondary resistance to immunotherapy is common in patients with diverse types of cancer. It is well-acknowledged that tumor cells can facilitate the formation of immunosuppressive microenvironments via metabolism reprogramming, and lactic acid, the metabolite of glycolysis, is a significant contributor. SLC16A3 (also named as MCT4) is a transporter mediating lactic acid efflux. In this study, we investigated the role of glycolysis in immunotherapy resistance and aimed to improve the immunotherapy effects via Slc16a3 inhibition. Bioinformatical analysis revealed that the expression of glycolysis-related genes correlated with less CD8+ T cell infiltration and increased myeloid-derived suppressor cells (MDSC) enrichment. We found that high glycolytic activity in tumor cells adversely affected the antitumor immune responses and efficacy of immunotherapy and radiotherapy. As the transporter of lactic acid, SLC16A3 is highly expressed in glycolytic B16-F10 (RRID: CVCL_0159) cells, as well as human non-small cell lung carcinoma. We validated that Slc16a3 expression in tumor cells negatively correlated with anti-PD-1 efficiency. Overexpression of Slc16a3 in tumor cells promoted lactic acid production and efflux, and reduced tumor response to anti-PD-1 inhibitors by inhibiting CD8+ T cell function. Genetic and pharmacological inhibition of Slc16a3 dramatically reduced the glycolytic activity and lactic acid production in tumor cells, and ameliorated the immunosuppressive tumor microenvironments (TMEs), leading to boosted antitumor effects via anti-PD-1 blockade. Our study therefore demonstrates that tumor cell-intrinsic SLC16A3 may be a potential target to reverse tumor resistance to immunotherapy.

Analysis of transjugular intrahepatic portosystemic shunt by hemodynamic simulation.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS), which artificially creates a portocaval shunt to reduce portal venous pressure, has gradually become the primary treatment for portal hypertension (PH). However, there is no prefect shunting scheme in TIPS to balance the occurrence of postoperative complications and effective haemostasis. OBJECTIVE: To construct cirrhotic PH models and compare different shunting schemes in TIPS. METHODS: Three cases of cirrhotic PH with different liver volumes were selected for enhanced computed tomography scanning. The models for different shunting schemes were created using Mimics software, and following FLUENT calculation, all the models were imported into the software computational fluid dynamic-post for processing. In each shunting scheme, the differences in portal vein pressure, hepatic blood perfusion and blood flow from the superior mesenteric vein in the shunt tract were compared. The coefficient G was adapted to evaluate the advantages and disadvantages. RESULTS: (1) Concerning the precise location of the shunt tract, the wider the diameter of the shunt tract, the lower the pressure of the portal vein and the lesser the hepatic blood perfusion. Meanwhile, the pressure drop objective was not achieved with the 6 mm-diameter shunting scheme. (2) The 8 mm-diameter shunting scheme through the left portal vein (LPV) had the highest coefficient G. CONCLUSION: The 8 mm-diameter shunting scheme through the LPV may demonstrate a superior effect and prognosis in TIPS procedures.

Pan-cancer analysis identifies protein arginine methyltransferases PRMT1 and PRMT5 and their related signatures as markers associated with prognosis, immune profile, and therapeutic response in lung adenocarcinoma.

Purpose: Protein arginine methyltransferases (PRMTs) regulate several signal transduction pathways involved in cancer progression. Recently, it has been reported that PRMTs are closely related to anti-tumor immunity; however, the underlying mechanisms have yet to be studied in lung adenocarcinoma (LUAD). In this study, we focused on PRMT1 and PRMT5, key members of the PRMT family. And their signatures in lung carcinoma associated with prognosis, immune profile, and therapeutic response including immunotherapy and radiotherapy were explored. Methods: To understand the function of PRMT1 and PRMT5 in tumor cells, we examined the association between the expression of PRMT1 and PRMT5 and the clinical, genomic, and immune characteristics, as well as the sensitivity to immunotherapy and radiotherapy. Specifically, our investigation focused on the role of PRMT1 and PRMT5 in tumor progression, with particular emphasis on interferon-stimulated genes (ISGs) and the pathway of type I interferon. Furthermore, the influence of proliferation, migration, and invasion ability was investigated based on the expression of PRMT1 and PRMT5 in human lung adenocarcinoma cell lines. Results: Through the examination of receiver operating characteristic (ROC) and survival studies, PRMT1 and PRMT5 were identified as potential biomarkers for the diagnosis and prognosis. Additionally, heightened expression of PRMT1 or PRMT5 was associated with immunosuppressive microenvironments. Furthermore, a positive correlation was observed between the presence of PRMT1 or PRMT5 with microsatellite instability, tumor mutational burden, and neoantigens in the majority of cancers. Moreover, the predictive potential of PRMT1 or PRMT5 in individuals undergoing immunotherapy has been acknowledged. Our study ultimately revealed that the inhibition of PRMT1 and PRMT5 in lung adenocarcinoma resulted in the activation of the cGAS-STING pathway, especially after radiation. Favorable prognosis was observed in lung adenocarcinoma patients receiving radiotherapy with reduced PRMT1 or PRMT5 expression. It was also found that the expression of PRMT1 and PRMT5 influenced proliferation, migration, and invasion of human lung adenocarcinoma cell lines. Conclusion: The findings indicate that PRMT1 and PRMT5 exhibit potential as immune-related biomarkers for the diagnosis and prognosis of cancer. Furthermore, these biomarkers could be therapeutically targeted to augment the efficacy of immunotherapy and radiotherapy in lung adenocarcinoma.

Inhibition of tumor intrinsic BANF1 activates antitumor immune responses via cGAS-STING and enhances the efficacy of PD-1 blockade.

BACKGROUND: BANF1 is well known as a natural opponent of cyclic GMP-AMP synthase (cGAS) activity on genomic self-DNA. However, the roles of BANF1 in tumor immunity remain unclear. Here, we investigate the possible impact of BANF1 on antitumor immunity and response to immunotherapy. METHODS: The Cancer Genome Atlas public data were analyzed to evaluate the relevance of the expression of BANF1, patients' survival and immune cell infiltration. We monitored tumor growth and explored the antitumor efficacy of targeting tumor-intrinsic BANF1 in combination with anti-programmed cell death protein-1 (PD-1) in MC38 or B16F10 tumor models in both immunocompetent and immunodeficient mice. Flow cytometry, immunofluorescence and T cells depletion experiments were used to validate the role of BANF1 in tumor immune microenvironment reprogramming. RNA sequencing was then used to interrogate the mechanisms how BANF1 regulated antitumor immunity. RESULTS: We show that upregulated expression of BANF1 in tumor tissues is significantly associated with poor survival and is negatively correlated with immune cell infiltration. Deficiency of BANF1 in tumor cells markedly antagonizes tumor growth in immunocompetent but not immunocompromised mice, and enhances the response to immunotherapy in murine models of melanoma and colon cancer. In the immunotherapy clinical cohort, patients with high BANF1 expression had a worse prognosis. Mechanistically, BANF1 knockout activates antitumor immune responses mediated by cGAS-synthase-stimulator of interferon genes (cGAS-STING) pathway, resulting in an immune-activating tumor microenvironment including increased CD8+ T cell infiltration and decreased myeloid-derived suppressor cell enrichment. CONCLUSIONS: BANF1 is a key regulator of antitumor immunity mediated by cGAS-STING pathway. Therefore, our study provides a rational that targeting BANF1 is a potent strategy for enhancing immunotherapy for cancer with BANF1 upregulation.

The prognostic value of postoperative radiotherapy in right tumor for lung related death: based on SEER database and real-world data.

Background: Postoperative radiotherapy (PORT) is a therapeutic strategy for patients with non-small cell lung cancer (NSCLC). Nevertheless, some studies suggesting PORT does not improve overall survival (OS) including Lung ART phase III trial. The role of PORT and high-risk groups need to be confirmed. Methods: Patients from the Surveillance, Epidemiology, and End Results program (SEER) from 2004 to 2015 were eligible. Aged ≥18 years with stage IIIA-N2 NSCLC, accepted PORT or not were considered for the study. Cox regression analyses and multivariate competing risk model were performed. Propensity score matching (PSM) was conducted. Data from a single-center study in China were used for validation. Results: In all patients with IIIA-N2 NSCLC, death from respiratory illness increased year by year, with right lung-related deaths accounting for the main proportion. In SEER database, PORT was detrimental for OS after PSM (hazard ratio [HR], 1.088; 95% CI, 1.088-1.174; P = 0.031), with a same trend for death from the lungs (HR, 1.13; 95% CI, 1.04-1.22; P = 0.005). Right tumor receiving PORT were prone to death from lung disease(HR, 1.14; 95% CI, 1.02-1.27; P = 0.018). In China single-center cohort, PORT was significantly correlated with deteriorated OS (HR 1.356; 95% CI 1.127-1.632; P <0.01), especially in the right laterality (HR 1.365; 95% CI 1.062-1.755; P = 0.015). Conclusions: PORT was a risk factor for stage IIIA-N2 NSCLC patients, particularly with characters of right laterality, male sex, age ≥65 years, and advanced tumor stage. These patients are more likely to death from lung disease after PORT.

Dual effect of radiotherapy related concomitant cardiovascular diseases in non-small cell lung cancer.

BACKGROUND: Nowadays, cancer and cardiac diseases are two of the most causes of death, so cancer treatment-related cardiac death cannot be ignored. For lung cancer, chest radiotherapy (RT) is essential, but the related cardiotoxicity has not been fully studied. METHODS: We reviewed the data of 11,455 patients with non-small cell lung cancer (NSCLC) from the Surveillance, Epidemiology, and End Results database from 2001 to 2015. The change trend for concomitant cardiovascular diseases (CVD)-specific death was calculated and graphically demonstrated. Univariate and multivariate analyses for survival were performed using Cox risk regression model. RESULTS: In our analysis, the overall incidence and mortality from NSCLC declined, but CVD-specific death increased. Both chemoradiotherapy and radiotherapy alone played a significant role in CVD-specific death. Analyzed longitudinally from diagnosis, we found that the effect of RT in CVD-specific death increased continuously over the third years and the hazard ratio for CVD-specific death was 1.386 times between RT and non-RT group (HR = 1.386, 95% CI 1.322-1.452; p < 0.0001). On the other hand, RT played a protective role in CVD-specific death before the second years, especially in recent years from 2013 to 2015 (HR = 0.843, 95% CI 0.740-0.959; p = 0.009). CONCLUSIONS: Although the mortality from NSCLC decreased, but radiotherapy-related CVD-specific mortality cannot be ignored. In the long-term over 3 years, RT significantly promoted CVD-specific death. However, RT turned to be a protective role in the short-term within 2 years. In clinical practice, we need to comprehensively consider the dual effects of radiotherapy on the side effect of heart.

Postoperative radiotherapy might be a risk factor for second primary lung cancer: A population-based study.

Background: Surgery is the main curative therapeutic strategy for patients with initial primary lung cancer (IPLC). Most international guidelines recommend regular follow-ups after discharge to monitor patients for tumor recurrence and metastasis. As the overall survival (OS) in patients with lung cancer improves, their risk of secondary primary lung cancer (SPLC) increases. Previous studies on such patients lack separate assessment of different survival outcomes and evaluation of high-risk factors for SPLC. Therefore, we aimed to determine the correlation between high-risk factors and causes of death in patients with SPLC, based on the Surveillance, Epidemiology, and End Results (SEER) database. Methods: We screened the SEER database for patients with IPLC and SPLC from 2004 to 2015 and included only patients who underwent surgery since the IPLC and in whom the cancer was pathologically verified of an International Classification of Diseases grade of 0-3 and to be non-small-cell lung cancer. The standardized incidence ratio (SIR) was calculated between variables and SPLC. Multivariable Cox proportional-hazards regression analyses were conducted to calculate the correlation of different variables with overall survival (OS) and cancer-specific survival (CSS). A competing-risk model was conducted for SPLC. The effect of baseline bias on survival outcomes by performing propensity score matching analysis in a 1: 6 ratio (SPLC: IPLC). Results: For patients aged 0-49 years, the overall SIR was higher in older patients, reaching a maximum of 27.74 in those aged 40-49 years, and at 11.63 in patients aged 50-59 years. The overall SIR was higher for patients who were more recently diagnosed with IPLC and increased with time after diagnosis. Male sex, SPLC (hazard ratio, 1.6173; 95% confidence interval, 1.5505-1.6869; P < 0.001), cancer grade III or IV, lower lobe of the lung, advanced stage and postoperative radiotherapy (PORT) were independently detrimental to OS. In terms of CSS, PORT was a high-risk factor. Conclusions: Postoperative radiotherapy is a risk factor for second primary lung cancer and detrimental to overall and cancer-specific survival in patients who had initial primary lung cancer. These data support the need for life-long follow-up of patients who undergo treatment for IPLC to screen for SPLC.

Psychological State and Decision Perceptions of Male and Female Cancer Patients on Fertility Preservation.

OBJECTIVE: This study explored the emotional state and decision perceptions of fertility preservation (FP) decisions of male and female cancer patients undergoing FP. SETTING: Obstetrics & Gynecology Hospital of Fudan University. METHOD: All patients with a cancer diagnosis were referred by their physician to contact a fertility preservation specialist for FP plan discussion. After FP counseling, participants completed sociodemographic and basic information surveys and validated psychological and decisional scales. RESULTS: The final sample included 17 male and 16 female cancer FP patients. Overall, 85% of participants reported currently undergoing moderate to severe depression and anxiety states. Sex differences were found in both depression and anxiety states (P < 0.05). Both genders demonstrated a low level of regret in the decision to preserve fertility, indicating that participants felt they had made the right decision. However, there displayed decisional conflict, suggesting that cancer patients felt high conflict when making decisions. CONCLUSION: In conclusion, there is a nonnegligible emotional burden on FP patients who have already undergone a painful situation before the start of oncological treatment. This is the first study to use validated DRS to examine emotional problems occurring in both men and women during FP decision-making.

Molecular Sparse Representation by a 3D Ellipsoid Radial Basis Function Neural Network via L1 Regularization.

The three-dimensional structures and shapes of biomolecules provide essential information about their interactions and functions. Unfortunately, the computational cost of biomolecular shape representation is an active challenge which increases rapidly as the number of atoms increase. Recent developments in sparse representation and deep learning have shown significant improvements in terms of time and space. A sparse representation of molecular shape is also useful in various other applications, such as molecular structure alignment, docking, and coarse-grained molecular modeling. We have developed an ellipsoid radial basis function neural network (ERBFNN) and an algorithm for sparsely representing molecular shape. To evaluate a sparse representation model of molecular shape, the Gaussian density map of the molecule is approximated using ERBFNN with a relatively small number of neurons. The deep learning models were trained by optimizing a nonlinear loss function with L1 regularization. Experimental results reveal that our algorithm can represent the original molecular shape with a relatively higher accuracy and fewer scale of ERBFNN. Our network in principle is applicable to the multiresolution sparse representation of molecular shape and coarse-grained molecular modeling. Executable files are available at https://github.com/SGUI-LSEC/SparseGaussianMolecule. The program was implemented in PyTorch and was run on Linux.

Quality improvement of surface triangular mesh using a modified Laplacian smoothing approach avoiding intersection.

We present a systematic procedure to improve the qualities of triangular molecular surface meshes and at the same time preserve the manifoldness. The procedure utilizes an algorithm to remove redundant points having three or four valences and another algorithm to smooth the mesh using a modified version of Laplacian method without causing intersecting triangles. This approach can be effectively applied to any manifold surface meshes with arbitrary complex geometry. In this paper, the tested meshes are biomolecular surface meshes exhibiting typically highly irregular geometry. The results show that the qualities of the surface meshes are greatly improved and the manifoldness of the surface meshes are preserved. Compared with the original meshes, these improved molecular surface meshes can be directly applied to boundary element simulations and generation of body-fitted volume meshes using Tetgen. The procedure has been incorporated into our triangular molecular surface mesh generator, TMSmesh 2.0. It can be also used as a standalone program and works together with any other surface triangular mesh generator to obtain qualified manifold mesh. The package is downloadable at https://doi.org/10.6084/m9.figshare.5346169.v1 and can be run online at http://www.xyzgate.com.

Parameterization for molecular Gaussian surface and a comparison study of surface mesh generation.

The molecular Gaussian surface has been frequently used in the field of molecular modeling and simulation. Typically, the Gaussian surface is defined using two controlling parameters; the decay rate and isovalue. Currently, there is a lack of studies in which a systematic approach in the determination of optimal parameterization according to the geometric features has been done. In this paper, surface area, volume enclosed by the surface and Hausdorff distance are used as three criteria for the parameterization to make the Gaussian surface approximate the solvent excluded surface (SES) well. For each of these three criteria, a search of the parameter space is carried out in order to determine the optimal parameter values. The resulted parameters are close to each other and result in similar calculated molecular properties. Approximation of the VDW surface is also done by analyzing the explicit expressions of the Gaussian surface and VDW surface, which analysis and parameters can be similarly applied to the solvent accessible surface (SAS) due to its geometric similarity to the VDW surface. Once the optimal parameters are obtained, we compare the performance of our Gaussian surface generation software TMSmesh with other commonly used software programs, focusing primarily on mesh quality and fidelity. Additionally, the Poisson-Boltzmann solvation energies based on the surface meshes generated by TMSmesh and those generated by other software programs are calculated and compared for a set of molecules with different sizes. The results of these comparisons validate both the accuracy and the applicability of the parameterized Gaussian surface.

Computation of the memory functions in the generalized Langevin models for collective dynamics of macromolecules.

We present a numerical method to approximate the memory functions in the generalized Langevin models for the collective dynamics of macromolecules. We first derive the exact expressions of the memory functions, obtained from projection to subspaces that correspond to the selection of coarse-grain variables. In particular, the memory functions are expressed in the forms of matrix functions, which will then be approximated by Krylov-subspace methods. It will also be demonstrated that the random noise can be approximated under the same framework, and the second fluctuation-dissipation theorem is automatically satisfied. The accuracy of the method is examined through several numerical examples.

A parallel finite element simulator for ion transport through three-dimensional ion channel systems.

A parallel finite element simulator, ichannel, is developed for ion transport through three-dimensional ion channel systems that consist of protein and membrane. The coordinates of heavy atoms of the protein are taken from the Protein Data Bank and the membrane is represented as a slab. The simulator contains two components: a parallel adaptive finite element solver for a set of Poisson-Nernst-Planck (PNP) equations that describe the electrodiffusion process of ion transport, and a mesh generation tool chain for ion channel systems, which is an essential component for the finite element computations. The finite element method has advantages in modeling irregular geometries and complex boundary conditions. We have built a tool chain to get the surface and volume mesh for ion channel systems, which consists of a set of mesh generation tools. The adaptive finite element solver in our simulator is implemented using the parallel adaptive finite element package Parallel Hierarchical Grid (PHG) developed by one of the authors, which provides the capability of doing large scale parallel computations with high parallel efficiency and the flexibility of choosing high order elements to achieve high order accuracy. The simulator is applied to a real transmembrane protein, the gramicidin A (gA) channel protein, to calculate the electrostatic potential, ion concentrations and I - V curve, with which both primitive and transformed PNP equations are studied and their numerical performances are compared. To further validate the method, we also apply the simulator to two other ion channel systems, the voltage dependent anion channel (VDAC) and α-Hemolysin (α-HL). The simulation results agree well with Brownian dynamics (BD) simulation results and experimental results. Moreover, because ionic finite size effects can be included in PNP model now, we also perform simulations using a size-modified PNP (SMPNP) model on VDAC and α-HL. It is shown that the size effects in SMPNP can effectively lead to reduced current in the channel, and the results are closer to BD simulation results.

Triangulated manifold meshing method preserving molecular surface topology.

Generation of manifold mesh is an urgent issue in mathematical simulations of biomolecule using boundary element methods (BEM) or finite element method (FEM). Defects, such as not closed mesh, intersection of elements and missing of small structures, exist in surface meshes generated by most of the current meshing method. Usually the molecular surface meshes produced by existing methods need to be revised carefully by third party software to ensure the surface represents a continuous manifold before being used in a BEM and FEM calculations. Based on the trace technique proposed in our previous work, in this paper, we present an improved meshing method to avoid intersections and preserve the topology of the molecular Gaussian surface. The new method divides the whole Gaussian surface into single valued pieces along each of x, y, z directions by tracing the extreme points along the fold curves on the surface. Numerical test results show that the surface meshes produced by the new method are manifolds and preserve surface topologies. The result surface mesh can also be directly used in surface conforming volume mesh generation for FEM type simulation.

TMSmesh: A Robust Method for Molecular Surface Mesh Generation Using a Trace Technique.

Qualified, stable, and efficient molecular surface meshing appears to be necessitated by recent developments for realistic mathematical modeling and numerical simulation of biomolecules, especially in implicit solvent modeling (e.g., see a review in B. Z. Lu et al. Commun. Comput. Phys. 2008, 3, 973-1009). In this paper, we present a new method: tracing molecular surface for meshing (TMSmesh) the Gaussian surface of biomolecules. The method computes the surface points by solving a nonlinear equation directly, polygonizes by connecting surface points through a trace technique, and finally outputs a triangulated mesh. TMSmesh has a linear complexity with respect to the number of atoms and is shown to be capable of handling molecules consisting of more than one million atoms, which is usually difficult for the existing methods for surface generation used in molecular visualization and geometry analysis. Moreover, the meshes generated by TMSmesh are successfully tested in boundary element solutions of the Poisson-Boltzmann equation, which directly gives rise to a route to simulate electrostatic solvation of large-scale molecular systems. The binary version of TMSmesh and a set of representative PQR benchmark molecules are downloadable at our Web page http://lsec.cc.ac.cn/∼lubz/Meshing.html .

The role of NF-kappaB in hepatocellular carcinoma cell.

OBJECTIVE: To evaluate the role of nuclear factor-kappa B (NF-kappaB) and inhibitory kappaB alpha (IkappaBalpha) in hepatocellular cacinoma (HCC) SMMC7721 cells, the consequence of NF-kappaB inhibition in SMMC7721 cells transfected with mutated IkappaBalpha (mIkappaBalpha) plasmid and the effect of stable inhibition of NF-kappaB activity in combination with Doxorubicin. METHODS: Western blot was used to determine the expression of NF-kappaB and IkappaBalpha in SMMC7721 cells and normal liver cells. Nuclear protein was used to evaluate the binding of the (32)P-labeled tandem kappaB sequence using electrophoretic mobility shift assay and the expression of NF-kappaB using Western blot between SMMC7721 cells transfected with mIkappaBalpha plasmid (SMMC7721-MT) and control cells. Furthermore, cell viability was plotted between SMMC7721-MT and control cells. The binding of kappaB sequence and cell viability between SMMC7721-MT and control cells at different concentrations of Doxorubicin were also investigated. RESULTS: Western blot analysis for nuclear extract showed more P50 (NF-kappaB1) and P65 (RelA) expression in SMMC7721 cells compared with normal liver cells. The expression of cytosolic IkappaBalpha protein in SMMC7721 cells was less than that in normal cells. SMMC7721-MT cells inhibited NF-kappaB nuclear translocation at 0, 24, 48 and 96 hours. Furthermore, NF-kappaB cannot be detected in the nuclear protein of SMMC7721-MT cells by Western blot. By calculating cell viability, the proliferation of SMMC7721-MT cells was shown to be suppressed more significantly than that of control cells. NF-kappaB in untransfected cells was activated by Doxorubicin in a dose-dependent manner, but that in SMMC7721-MT cells was not induced at low concentrations of Doxorubicin. Compared with untransfected cells, the viability of SMMC7721-MT cells was significantly suppressed at the same concentration of Doxorubicin (P < 0.01). CONCLUSIONS: The present study demonstrates that upregulation of NF-kappaB and downregulation of inhibitory kappa B (IkappaBalpha) in SMMC7721 cells are related with the growth of hepatocellular cacinoma cells. Stable expression of mIkappaBalpha in SMMC7721-MT cells can inhibit NF-kappaB nuclear translocation and suppress cell growth. Furthermore, stable inhibition of NF-kappaB activity in combination with Doxorubicin can significantly inhibit cell proliferation in SMMC7721-MT cells. Thus, modulation of NF-kappaB may represent an improvement in the efficacy of HCC therapies and be worthy of further research and investigation.

[Nuclear factor kappa B activity and cell viability of SMMC-7721 inhibited by mutated inhibitor kappa B alpha].

OBJECTIVE: To investigate the inhibition consequence of NF-kappaB activity and cell viability by transfecting mutated inhibitor kappa B alpha (mI(kappa)B(alpha)) into liver cancer cell line of SMMC-7721 cells. METHODS: The nucleic proteins of SMMC-7721 cells transfected with mI(kappa)B(alpha) plasmid and cells with empty pcDNA3 vector were used to determine not only the binding of the 32P-labelled kappaB probes by EMSA, but also the expression of NF-kappaB by western blot. Cell viability was also analyzed. RESULTS: NF-kappaB nuclear translocation was inhibited remarkably in SMMC-7721 cells transfected with mI(kappa)B(alpha) at 0, 24, 48 and 96 hours. Furthermore, NF-kappaB was not detected in the nucleic protein of mI(kappa)B(alpha) -transfected cells at the same intended time by western blot. Compared with that of control cells, the growth of SMMC-7721 cells transfected with mI(kappa)B(alpha) was suppressed evidently, especially on the second day, the cpm values of mI(kappa)B(alpha) -transfected cells, pcDNA3-transfected cells, and control cells were 5,092.63+/-541.41, 7,851.87+/-72.76, and 8,240.8+/-603.26 respectively (t = 14.29, P<0.01; t = 10.99, P<0.01). CONCLUSION: Stable expression of mI(kappa)B(alpha) in SMMC-7721 cells transfected with mI(kappa)B(alpha) plasmid inhibits NF-kappaB nuclear translocation, then suppresses the cell growth.