Deregulation Of Cell Death Research Articles

METACASPASE8 (MC8) Is a Crucial Protein in the LSD1-Dependent Cell Death Pathway in Response to Ultraviolet Stress.

LESION-SIMULATING DISEASE1 (LSD1) is one of the well-known cell death regulatory proteins in Arabidopsis thaliana. The lsd1 mutant exhibits runaway cell death (RCD) in response to various biotic and abiotic stresses. The phenotype of the lsd1 mutant strongly depends on two other proteins, ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) and PHYTOALEXIN-DEFICIENT 4 (PAD4) as well as on the synthesis/metabolism/signaling of salicylic acid (SA) and reactive oxygen species (ROS). However, the most interesting aspect of the lsd1 mutant is its conditional-dependent RCD phenotype, and thus, the defined role and function of LSD1 in the suppression of EDS1 and PAD4 in controlled laboratory conditions is different in comparison to a multivariable field environment. Analysis of the lsd1 mutant transcriptome in ambient laboratory and field conditions indicated that there were some candidate genes and proteins that might be involved in the regulation of the lsd1 conditional-dependent RCD phenotype. One of them is METACASPASE 8 (AT1G16420). This type II metacaspase was described as a cell death-positive regulator induced by UV-C irradiation and ROS accumulation. In the double mc8/lsd1 mutant, we discovered reversion of the lsd1 RCD phenotype in response to UV radiation applied in controlled laboratory conditions. This cell death deregulation observed in the lsd1 mutant was reverted like in double mutants of lsd1/eds1 and lsd1/pad4. To summarize, in this work, we demonstrated that MC8 is positively involved in EDS1 and PAD4 conditional-dependent regulation of cell death when LSD1 function is suppressed in Arabidopsis thaliana. Thus, we identified a new protein compound of the conditional LSD1-EDS1-PAD4 regulatory hub. We proposed a working model of MC8 involvement in the regulation of cell death and we postulated that MC8 is a crucial protein in this regulatory pathway.

The Impact of the Microbiome on Resistance to Cancer Treatment with Chemotherapeutic Agents and Immunotherapy.

Understanding the mechanisms of resistance to therapy in human cancer cells has become a multifaceted limiting factor to achieving optimal cures in cancer patients. Besides genetic and epigenetic alterations, enhanced DNA damage repair activity, deregulation of cell death, overexpression of transmembrane transporters, and complex interactions within the tumor microenvironment, other mechanisms of cancer treatment resistance have been recently proposed. In this review, we will summarize the preclinical and clinical studies highlighting the critical role of the microbiome in the efficacy of cancer treatment, concerning mainly chemotherapy and immunotherapy with immune checkpoint inhibitors. In addition to involvement in drug metabolism and immune surveillance, the production of microbiota-derived metabolites might represent the link between gut/intratumoral bacteria and response to anticancer therapies. Importantly, an emerging trend of using microbiota modulation by probiotics and fecal microbiota transplantation (FMT) to overcome cancer treatment resistance will be also discussed.

Vanadium in the environment as a risk factor causing negative modification of cell death (scientific review)

The review dwells on results obtained via examinations that focused on effects produced by vanadium and its compounds contaminating the environment on health disorders related to cell death deregulation. Research works that have been performed over the last decades and focused on revealing the essence of apoptosis mechanism under exposure to technogenic chemicals are truly vital due to this phenomenon having great biological significance within a system of a body trying to adapt to influences exerted by environmental factors. The present work focuses on apoptosis peculiarities under exposure to excess technogenic concentrations of vanadium compounds. Published research works have been analyzed, analysis results are outlined, and a scientific hypothesis has been formulated within the subject matter. We have described an immune-modulating effect produced by vanadium compounds that is able to modify apoptosis events due to changes in cell death modes (apoptosis activation/inhibition) and it provides body adaptation to changing environmental conditions. A range in vanadium concentrations between essential and toxic ones predetermines multi-directional changes in apoptosis induction and completion. Thus, induced apoptosis activation makes for development of autoimmune and immune-proliferative processes; at the same time, cell death inhibition can result in immune deficiency, inflammatory reactions, and neurodegenerative diseases. It was shown that vanadium compounds produced modifying effects on mitochondrial functions regulation, changes in phosphorilation/dephosphorilation ratio in protein products, and imbalance in free radical processes; all this ultimately disrupts a balance between pro- and anti-apoptotic signals in a cell. Monitoring over apoptosis parameters that characterize cell death under exposure to vanadium and its compounds will allow timely detecting risks of pre-nosology state occurrence and prevent damage to health

Ванадий в среде обитания как фактор риска негативной модификации клеточной гибели (научный обзор)

The review dwells on results obtained via examinations that focused on effects produced by vanadium and its compounds contaminating the environment on health disorders related to cell death deregulation. Research works that have been performed over the last decades and focused on revealing the essence of apoptosis mechanism under exposure to technogenic chemicals are truly vital due to this phenomenon having great biological significance within a system of a body trying to adapt to influences exerted by environmental factors. The present work focuses on apoptosis peculiarities under exposure to excess technogenic concentrations of vanadium compounds. Published research works have been analyzed, analysis results are outlined, and a scientific hypothesis has been formulated within the subject matter. We have described an immune-modulating effect produced by vanadium compounds that is able to modify apoptosis events due to changes in cell death modes (apoptosis activation/inhibition) and it provides body adaptation to changing environmental conditions. A range in vanadium concentrations between essential and toxic ones predetermines multi-directional changes in apoptosis induction and completion. Thus, induced apoptosis activation makes for development of autoimmune and immune-proliferative processes; at the same time, cell death inhibition can result in immune deficiency, inflammatory reactions, and neurodegenerative diseases. It was shown that vanadium compounds produced modifying effects on mitochondrial functions regulation, changes in phosphorilation/dephosphorilation ratio in protein products, and imbalance in free radical processes; all this ultimately disrupts a balance between pro- and anti-apoptotic signals in a cell. Monitoring over apoptosis parameters that characterize cell death under exposure to vanadium and its compounds will allow timely detecting risks of pre-nosology state occurrence and prevent damage to health.

Abstract 2371: FBXL12 modulates Fanconi anaemia-BRCA signaling under conditions of oncogene-induced replication stress

Abstract Oncogene-induced replication stress (OIRS) constitutes an early obstacle to cancer progression. De-regulation of cell death or senescence programs contribute to overcoming this barrier. However, even after escaping these fail-safe mechanisms, cancer cells need to handle elevated levels of DNA damage and ensuing genomic instability in order to continue proliferating. How this is achieved is only partially understood. To advance our understanding of this response and to identify potentially druggable regulators, we screened the family of human F-box proteins (FBP) for effects on replication re-start under conditions of OIRS. FBPs function as interchangeable substrate recognition sub-units of the SKP1-Cullin1-FBP ubiquitin ligase complex. They are required for conferring substrate specificity to the complex and some FBPs have been attributed roles as oncogenes or tumor suppressors while the majority remain largely uncharacterized. Our screen revealed the relatively unknown FBP FBXL12 as crucial regulator for sustained proliferation and genomic integrity under conditions of cyclin E-induced replication stress. FBXL12-depleted cells exhibit excessive replication fork stalling, high levels of DNA damage signaling and spontaneous senescence in OIRS breast cancer model cell lines. Interestingly, the same effects are not manifest in untransformed cell lines. Furthermore, we found that FBXL12 interacts with central chromatin-associated components of the Fanconi anemia (FA)-BRCA signaling pathway, ubiquitylating and targeting them for proteasomal degradation, and thereby exerting its effects on stalled replication forks. The specific nature of FA-BRCA signaling regulation by FBXL12 as well as potential clinical implications for basal-like breast cancers will be discussed. Citation Format: Andrä Brunner, Henrik Johansson, Alexandros Kourtesakis, Juha Rantala, Charles Spruck, James Wohlschlegel, Janne Lehtiö, Olle Sangfelt. FBXL12 modulates Fanconi anaemia-BRCA signaling under conditions of oncogene-induced replication stress [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2371.

TNF-α Modulates P-Glycoprotein Expression and Contributes to Cellular Proliferation via Extracellular Vesicles.

P-glycoprotein (Pgp/ABCB1) overexpression is associated with multidrug resistance (MDR) phenotype and, consequently, failure in cancer chemotherapy. However, molecules involved in cell death deregulation may also support MDR. Tumor necrosis factor-alpha (TNF-α) is an important cytokine that may trigger either death or tumor growth. Here, we examined the role of cancer cells in self-maintenance and promotion of cellular malignancy through the transport of Pgp and TNF-α molecules by extracellular vesicles (membrane microparticles (MP)). By using a classical MDR model in vitro, we identified a positive correlation between endogenous TNF-α and Pgp, which possibly favored a non-cytotoxic effect of recombinant TNF-α (rTNF-α). We also found a positive feedback involving rTNF-α incubation and TNF-α regulation. On the other hand, rTNF-α induced a reduction in Pgp expression levels and contributed to a reduced Pgp efflux function. Our results also showed that parental and MDR cells spontaneously released MP containing endogenous TNF-α and Pgp. However, these MP were unable to transfer their content to non-cancer recipient cells. Nevertheless, MP released from parental and MDR cells elevated the proliferation index of non-tumor cells. Collectively, our results suggest that Pgp and endogenous TNF-α positively regulate cancer cell malignancy and contribute to changes in normal cell behavior through MP.

The role of apoptosis defects in malignant mesothelioma pathogenesis with an impact on prognosis and treatment.

Malignant mesothelioma (MM) is a highly aggressive tumor that is strongly related to asbestos fiber exposure. The tumorigenesis procedure in MM is complex, and many pathogenetic mechanisms including chronic inflammation, deregulation of cell death, and the genomic copy-number losses and gains may contribute to carcinogenesis. MM cells are resistant to TRAIL-mediated apoptosis due to defects in extrinsic apoptotic pathway. CAPS, a regulator of cell cycle and death, may contribute to the MM development as well. BAP1 is the most frequently inactivated gene in MPM; BAP1 deficiency triggers malignant transformation via disruption of DNA repair, transcription regulation, cell metabolism, apoptosis, and ferroptosis. In addition, bcl-2 family proteins as well as abnormal activation of PI3K/Akt/mTOR pathway and deregulation of the Wnt signaling pathway may result in MM tumorigenesis. Finally, the Hippo pathway plays a critical role in MPM development. Mutations of NF2 and LATS lead to YAP activation in MPM. Thus, inhibition of YAP activity by YAP inhibitors could be a potentially promising treatment option for MM. In conclusion, extensive genetic alterations exist in mesotheliomas associated with the signaling of apoptotic HM cells death. The comprehension of these pathways may contribute to enhancing survival via developing new effective therapeutic strategies.

Effects of Natural Products on Mcl-1 Expression and Function.

Cancer development is mostly due to a deregulation of cell death as cancer cells become resistant to apoptosis by increasing expression of anti-apoptotic proteins belonging to the Bcl-2 family. Mcl-1 is one anti-apoptotic protein, which is mainly responsible for cancer cell resistance as it is overexpressed by most cancer cell types. Many research projects aim to restore cancer cell death by using natural pharmacological scaffolds targeting anti-apoptotic proteins to inhibit their effect in cancer development. This review introduces natural compound inhibitors of the Bcl-2 protein family with a focus on Mcl-1.

Pathophysiological mechanisms of death resistance in colorectal carcinoma.

Colon cancers develop adaptive mechanisms to survive under extreme conditions and display hallmarks of unlimited proliferation and resistance to cell death. The deregulation of cell death is a key factor that contributes to chemoresistance in tumors. In a physiological context, balance between cell proliferation and death, and protection against cell damage are fundamental processes for maintaining gut epithelial homeostasis. The mechanisms underlying anti-death cytoprotection and tumor resistance often bear common pathways, and although distinguishing them would be a challenge, it would also provide an opportunity to develop advanced anti-cancer therapeutics. This review will outline cell death pathways (i.e., apoptosis, necrosis, and necroptosis), and discuss cytoprotective strategies in normal intestinal epithelium and death resistance mechanisms of colon tumor. In colorectal cancers, the intracellular mechanisms of death resistance include the direct alteration of apoptotic and necroptotic machinery and the upstream events modulating death effectors such as tumor suppressor gene inactivation and pro-survival signaling pathways. The autocrine, paracrine and exogenous factors within a tumor microenvironment can also instigate resistance against apoptotic and necroptotic cell death in colon cancers through changes in receptor signaling or transporter uptake. The roles of cyclooxygenase-2/prostaglandin E2, growth factors, glucose, and bacterial lipopolysaccharides in colorectal cancer will be highlighted. Targeting anti-death pathways in the colon cancer tissue might be a promising approach outside of anti-proliferation and anti-angiogenesis strategies for developing novel drugs to treat refractory tumors.

The relation of pericoronal third molar follicle dimension and bcl-2/ki-67 expression: An immunohistochemical study.

Background:Most common impacted teeth are the mandibular third molars and decision about extraction of them is usually controversial. The presence of pericoronal pathologic changes is an acceptable reason for removal of impacted teeth. Differences in the proliferation rate and apoptosis of odontogenic epithelial cells may influence on the formation of odontogenic epithelial lesions. Therefore, the aim of the present study is to evaluate the immunohistochemical expression of the bcl-2 apoptosis-inhibiting protein and the cell-cycle-related ki-67 antigen in pericoronal follicle of impacted third molars with ≥2.5 mm and <2.5 mm radiolucency.Materials and Methods:This was a cross-sectional study that 20 follicles with <2.5 mm radiolucency and 20 follicles with ≥2.5 mm radiolucency were selected by a professional radiologist in digital panoramic radiographs and then referred to a surgeon. Formalin fixed paraffin-embedded tissues were immunohistochemical analyzed for immunoreactivity of bcl-2 protein and ki-67 antigen. The data was analyzed using logistic regression, Spearman correlation coefficient and t-test and Mann-Whitney. P<0.05 was considered significant.Results:The findings showed correlation between size of the third molar's follicles and expression of bcl-2 protein (P < 0.001, r = 0.556) but there was no correlation between size of third molar's follicles and staining with ki-67 antigen (P = 0.546, r = 0.098). The follicles with radiolucency ≥2.5 mm showed increased immunoreactivity for bcl-2 protein.Conclusion:The results of study suggest that impacted third molars with radiolucency ≥2.5 mm may be associated with deregulation of cell death, indicated with increased expression of the anti- apoptotic protein bcl-2, while cell proliferation (ki-67) does not seem to play a significant role.

Targeting Osteopontin Splice Variation to Increase Chemo-Sensitivity and Decrease Malignant Potential in Non-Small Cell Lung Cancer

Introduction: Cisplatin resistance by non-small cell lung cancer (NSCLC) is a vital medical problem resulting from deregulation of cell death and survival pathways. Osteopontin (OPN) is a ubiquitous protein associated with a wide range of normal and pathologic functions. It is a central regulator of the malignant phenotype in NSCLC and an instrument used to elude apoptosis when under stress, via αvB3integrin binding at OPN's central RGD domain. the three naturally occurring OPN splice variants are differentially expressed in NSCLC and have divergent impact on malignant potential.

From hepatitis to hepatocellular carcinoma: a proposed model for cross-talk between inflammation and epigenetic mechanisms.

Inflammation represents the body's natural response to tissue damage; however, chronic inflammation may activate cell proliferation and induce deregulation of cell death in affected tissues. Chronic inflammation is an important factor in the development of hepatocellular carcinoma (HCC), although the precise underlying mechanism remains unknown. Epigenetic events, which are considered key mechanisms in the regulation of gene activity states, are also commonly deregulated in HCC. Here, we review the evidence that chronic inflammation might deregulate epigenetic processes, thus promoting oncogenic transformation, and we propose a working hypothesis that epigenetic deregulation is an underlying mechanism by which inflammation might promote HCC development. In this scenario, different components of the inflammatory response might directly and indirectly induce changes in epigenetic machineries ('epigenetic switch'), including those involved in setting and propagating normal patterns of DNA methylation, histone modifications and non-coding RNAs in hepatocytes. We discuss the possibility that self-reinforcing cross-talk between inflammation and epigenetic mechanisms might amplify inflammatory signals and maintain a chronic state of inflammation culminating in cancer development. The potential role of inflammation-epigenome interactions in the emergence and maintenance of cancer stem cells is also discussed.

Immunohistochemical Analysis of a Dentigerous Cyst in a Dog

A dentigerous cyst is a cyst that encloses part or the entire crown of an impacted or late-erupting tooth and occurs with comparatively high frequency in humans. In animals, there are three different lesions that are similar to dentigerous cyst and this complexity has led to confusion. In order to clarify the dentigerous cyst most similar to that in humans especially with regard to characteristics of the lining epithelium, this report describes the clinical, pathological, and immunohistochemical features of a dentigerous cyst in a dog. Further, approaches to the surgical and dental management of this cyst in dogs are also discussed and the literature is reviewed. Extraction of an embedded right mandibular first premolar tooth and debridement of the dentigerous cyst soft tissue lining were performed in a 4-year-old female mixed-breed dog. Radiography showed a well-defined unilocular and radiolucent area associated with the crown of the unerupted tooth. Histologically, the unilocular cyst wall was mainly lined by non-keratinized stratified flattened epithelium. As in humans, canine dentigerous cyst can be appropriately treated by cyst enucleation after accurate diagnosis. The radiographic appearance of an unerupted tooth embedded in an osseous cyst wall is a significant characteristic finding. Moreover non-keratinized epithelium is immunoreactive for amelogenin and ssDNA, which might be associated with deregulation of cell death in the lining epithelium, derived from odontogenic origin. When encountering any questionable lesions, an accurate diagnosis and immediate treatment can avoid malignant transformation.

The p53 tumor suppressor network in cancer and the therapeutic modulation of cell death

The molecular subversion of cell death is acknowledged as a principal contributor to the development and progression of cancer. The p53 tumor suppressor protein is among the most commonly altered proteins in human cancer. The p53 protein mediates critical functions within cells including the response to genotoxic stress, differentiation, senescence, and cell death. Loss of p53 function can result in enhanced rates of cell proliferation, resistance to cell death stimuli, genomic instability, and metastasis. The community of cancer scientists is now in possession of a vast repository of information regarding the frequency, specific mechanisms, and clinical context of cell death deregulation in cancer. This information has enabled the design of therapeutic agents to target proteins, including p53. The feasibility and impact of targeting cell death signaling proteins has been established in preclinical models of human cancer. The appropriate application of these targeted agents is now being established in clinical trials.

The role of Bcl-2 family member BNIP3 in cell death and disease: NIPping at the heels of cell death.

Bcl-2 nineteen-kilodalton interacting protein (BNIP3) is a BH-3-only Bcl-2 family member whose expression levels increase during stress such as hypoxia through hypoxia-inducing factor-1-dependent or -independent mechanisms. When BNIP3 expression is induced, it localizes to the mitochondria and triggers a loss of membrane potential, and an increase in the reactive oxygen species production, which often leads to cell death. Cells under normal growth conditions suppress BNIP3 expression through transcriptional repression. There is considerable debate in the literature regarding what type of cell death is induced by BNIP3. It has been observed that BNIP3 could induce necrosis, autophagy and/or apoptosis. In contrast, other studies indicate that BNIP3 could promote cell survival. Besides its cell death regulation, BNIP3 plays a key role in the pathogenicity of many diseases. In cardiac infarction, loss of BNIP3 expression has been shown to reduce the number of damaged cardiomyocytes after ischemia and reperfusion. BNIP3 expression also plays an important role in the deregulation of cell death in many cancers. In this review, we will discuss the different and often contradictory mechanisms of BNIP3 regulation of cell death and the role that BNIP3 may play in diseases.

Expression of apoptotic and cell proliferation regulatory proteins in keratoacanthomas and squamous cell carcinomas of the skin

The aim of this study was to investigate the expression of p53, caspase-3, bcl-2, MIB-1, and PCNA to validate more objective methods to differentiate squamous cell carcinoma and keratoacanthoma, as well as to understand their pathogenesis with accuracy. A total of 52 cases of histopathologically diagnosed keratoacanthoma in the proliferative stage and 56 cases of well-differentiated squamous cell carcinoma were selected in this study. The expression was evaluated by means of immunohistochemistry. Bcl-2 immunoreactivity was weak or absent in the majority of cases, either in squamous cell carcinoma or in keratoacanthoma. PCNA-positive cells did not show differences between two lesions evaluated. On the other hand, MIB-1 was statistically significant ( p<0.05) between squamous cell carcinomas and keratoacanthomas. Moreover, p53 and caspase-3 were overexpressed in squamous cell carcinomas. Together, these results suggest that the biological behavior of the well-differentiated squamous cell carcinomas of the skin may be associated with cellular proliferation and/or deregulation of cell death, indicated by increased expression of the MIB-1 and apoptotic proteins p53 and caspase-3, respectively.

Mutational and expressional analysis of BNIP3, a pro‐apoptotic Bcl‐2 member, in gastric carcinomas

Cell death deregulation is a hallmark of human cancers. BNIP3 was initially identified as a pro-apoptotic member of the Bcl-2 family and plays an important role in apoptosis, necrosis and autophagy. The aim of this study was to see whether alterations of BNIP3 protein expression and somatic mutation of the BNIP3 gene are characteristics of human cancers. We analyzed the expression of BNIP3 protein in 60 gastric adenocarcinomas by immunohistochemistry. In addition, we analyzed BNIP3 mutation in the DNA sequences encoding BH3 (Bcl-2 homology3) and TM (transmembrane) domains that are important in the cell death function of BNIP3 by single-strand conformation polymorphism (SSCP) in 48 colorectal, 48 gastric, and 48 breast carcinomas, and 48 acute leukemias. By immunohistochemistry, BNIP3 protein was detected in 40 of the 60 carcinomas (67%). Both early and advanced gastric carcinomas expressed BNIP3. There was no significant association between BNIP3 expression and clinicopathologic characteristics, including invasion, metastasis and stage. In contrast to the cancer cells, epithelial cells in normal gastric mucosa showed no or weak expression of BNIP3. Mutational analysis revealed BNIP3 mutation in neither the BH3 nor the TM domain, suggesting that BNIP3 mutation in these domains is not a direct target of inactivation in gastric, colorectal and breast carcinomas, and acute leukemias. Increased expression of BNIP3 in the malignant gastric epithelial cells compared to the normal mucosal epithelial cells suggests that BNIP3 expression might play a role in gastric carcinoma development.

Growth and Trophic Factors, pH and the Na+/H+ Exchanger in Alzheimers Disease, Other Neurodegenerative Diseases and Cancer: New Therapeutic Possibilities and Potential Dangers

Abnormalities in the intricate intracellular signalling pathways play a key role in the deregulation of either spontaneous (normal or pathological) or induced (therapeutic) cell death mechanisms. Some of these pathways are increasingly becoming molecular therapeutic targets in different processes, ranging from neurodegenerative diseases to cancer. Recent discoveries in research and treatment have shown that failure to induce selective cell apoptosis in hyperproliferative processes, like neoplastic diseases, and the failure to prevent spontaneous cell death in neurodegenerative diseases (HNDDs) such as Alzheimer's disease (AD), multiple sclerosis (MS), amyothrophic lateral sclerosis (ALS), Huntington's disease (HD), and retinitis pigmentosa (RP), can be interpreted as problems stemming from the same basic mechanisms but moving in diametrically opposed directions. The integrated approach advanced here represents an interdisciplinary attempt to stimulate an integrated vision of two otherwise widely separated areas of research, experimental neurology and oncology. This kind of approach to the prevention of apoptosis (therapeutic antiapoptosis) and/or other forms of cell death in HNNDs, as well as to resistance to therapeutic apoptosis in cancer (pathological antiapoptosis), has the scope to improve the understanding of the dualistic nature of the basic abnormalities underlying the pathological deregulation of cell death. In this context, an intracellular pH (pH(i))-related approach to these opposed situations is advanced to provide a unified theory of the apoptosis-antiapoptosis machinery. Some potential therapeutic possibilities opened by these lines of research, regarding the utilization of human growth factors and/or cellular anti-acidification measures directed to sustain cellular acid-base homeostasis in different HNNDs are considered because of their potential therapeutic benefit. Finally, we advance some possible dangers and side-effects raised by these very same treatment efforts.

Mutational Analysis of Pro-apoptotic BNIP3 Gene in Non-Small Cell Lung Cancers

Purpose: Cell death deregulation is a hallmark of human cancers. BNIP3, which was initially identified as a pro-apoptotic member of the Bcl-2 family, plays an important role in apoptosis, necrosis and autophagy. This study was conducted to explore whether mutation of the BNIP3 gene is a characteristic of human non-small cell lung cancers (NSCLC). Materials and Methods: In the current study, we used polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP), and DNA sequencing to detect somatic mutations in the DNA sequences encoding the BH3 (Bcl-2 homology3) and TM (transmembrane) domains that are important to the cell death function of BNIP3 in 48 NSCLCs. Results: SSCP analysis revealed no evidence of somatic mutation in the DNA sequences encoding the BH3 and TM domains of the human BNIP3 gene in the 48 NSCLCs evaluated in this study. Conclusion: The data presented here indicate that the pro-apoptotic BNIP3 gene may not be somatically mutated in human NSCLCs, which suggests that mutational events of the BNIP3 gene may not be involved in the mechanisms by which NSCLCs evade cell death. (J Lung Cancer 2007;6(2):74�� 77)

Cytokine regulation of apoptosis and Bcl-2 expression in lymphocytes of patients with systemic lupus erythematosus.

Both faulty regulation of apoptosis and the inappropriate expression of several interleukins have been considered important defects of lymphocytes in the human autoimmune disease systemic lupus erythematosus (SLE). We therefore tested the in vitro effect of recombinant interleukin (IL-)-2, 4, 7, and 15 on peripheral blood mononuclear cells from patients with SLE and from healthy volunteers. Intracellular Bcl-2 and Bax expression was measured by fluorocytometry and the rate of apoptosis was determined by the TUNEL technique and propidium iodide staining. IL-2, IL-4, IL-7 and IL-15 led to a significant increase in Bcl-2 and a reduction in cell death rates, which was even more pronounced in SLE. Bax levels remained unchanged. Interestingly, the high ex vivo Bcl-2 content of lymphocytes from some SLE patients was maintained after growth factor withdrawal. Anti-apoptotic cytokine signaling may significantly influence the deregulation of cell death in SLE lymphocytes.