[Wu Shou and his work Shang Han Yun Yao Quan Shu published in the Ming Dynasty]

Wu Shou was a doctor in a medical family in Qiantang, Zhejiang in the Ming Dynasty. He was promoted as a medical officer in the local government and the Imperial Academy of Medicine. His work, considered a masterpiece Shang Han Yun Yao Quan Shu was published around 1505. The series consisted of four volumes. The main content of the book focused on the taxonomy study to the Treatise on Febrile Diseases (Shang Han Lun). Wu Shou was politically accused of being a person who pursued fame and fortune but lacked medical skills because of the conflicts and contradiction between medical officials and the political service system in the period of the Chenghua and Hongzhi in the Ming Dynasty. However, his medical and academic thinking and skills for typhoid treatment shown in the book demonstrated that they were not as awful as what was described at that time.

[Yi Wan She--Huzhou medical association in the late Ming Dynasty]

Yi Wan She, as a medical association in the Huzhou area, was organised by Lu Mingquan, Lu Shilong, Jin Desheng and other doctors in the late Ming Dynasty, developing daily medical theoretical discussions. It built up a hospital named Tian, paid deference to ancient medical doctors, and participated in activities to fight epidemics, organised by Hui Min Pharmacy, such as drug delivery, as an association of local affairs. This was recorded in Yi Wan She Cao and Lu Shi San Shi Yi Yan.

[The quotations of Yijing Dazhi from the Danxi Yi An]

The Yijing Dazhi (, Great Illustrated Directions on Medical Classics) was written by Haiyan He Yue in the Ming Dynasty. This book cited some sections from the Danxi Yi An ( , Danxi's Medical Cases), and some cases in this book were new discoveries. Using the method of philology, this paper compared the cited sections from the Danxi Yi An () in The Yijing Dazhi with the medical records in Danxi Yi An (), Gezhi Yu Lun (, Further Discourses on the Properties of Things), Danxi Zuanyao (, Collected Essentials of Master Danxi's Medical Book), and Danxi Zhifa Xinyao (, Heart and Essentials of Danxi's Treatment Methods). It found that Danxi Yi An() and Danxi Yi An () are actually two individual books. In addition, the contents of Yijing Dazhi cited from Danxi Yi An () are well preserved and have important reference value for collating the medical records of Zhu Danxi in other relevant medical archives.

Autophagy Promotes Cigarette Smoke-Initiated and Elastin-Driven Bronchitis-Like Airway Inflammation in Mice

Cigarette smoke (CS)-induced macrophage activation and airway epithelial injury are both critical for the development of chronic obstructive pulmonary disease (COPD), while the eventual functions of autophagy in these processes remain controversial. We have recently developed a novel COPD mouse model which is based on the autoimmune response sensitized by CS and facilitated by elastin. In the current study, we therefore utilized this model to investigate the roles of autophagy in different stages of the development of bronchitis-like airway inflammation. Autophagic markers were increased in airway epithelium and lung tissues, and Becn+/- or Lc3b-/- mice exhibited reduced neutrophilic airway inflammation and mucus hyperproduction in this COPD mouse model. Moreover, treatment of an autophagic inhibitor 3-methyladenine (3-MA) either during CS-initiated sensitization or during elastin provocation significantly inhibited the bronchitis-like phenotypes in mice. Short CS exposure rapidly induced expression of matrix metallopeptidase 12 (MMP12) in alveolar macrophages, and treatment of doxycycline, a pan metalloproteinase inhibitor, during CS exposure effectively attenuated the ensuing elastin-induced airway inflammation in mice. CS extract triggered MMP12 expression in cultured macrophages, which was attenuated by autophagy impairment (Becn+/- or Lc3b-/-) or inhibition (3-MA or Spautin-1). These data, taken together, demonstrate that autophagy mediates both the CS-initiated MMP12 activation in macrophages and subsequent airway epithelial injury, eventually contributing to development COPD-like airway inflammation. This study reemphasizes that inhibition of autophagy as a novel therapeutic strategy for CS-induced COPD.

Cigarette smoke-initiated autoimmunity facilitates sensitisation to elastin-induced COPD-like pathologies in mice

It is currently not understood whether cigarette smoke exposure facilitates sensitisation to self-antigens and whether ensuing auto-reactive T cells drive chronic obstructive pulmonary disease (COPD)-associated pathologies.To address this question, mice were exposed to cigarette smoke for 2 weeks. Following a 2-week period of rest, mice were challenged intratracheally with elastin for 3 days or 1 month. Rag1^-/- , Mmp12^-/- , and Il17a^-/- mice and neutralising antibodies against active elastin fragments were used for mechanistic investigations. Human GVAPGVGVAPGV/HLA-A*02:01 tetramer was synthesised to assess the presence of elastin-specific T cells in patients with COPD.We observed that 2 weeks of cigarette smoke exposure induced an elastin-specific T cell response that led to neutrophilic airway inflammation and mucus hyperproduction following elastin recall challenge. Repeated elastin challenge for 1 month resulted in airway remodelling, lung function decline and airspace enlargement. Elastin-specific T cell recall responses were dose dependent and memory lasted for over 6 months. Adoptive T cell transfer and studies in T cells deficient Rag1^-/- mice conclusively implicated T cells in these processes. Mechanistically, cigarette smoke exposure-induced elastin-specific T cell responses were matrix metalloproteinase (MMP)12-dependent, while the ensuing immune inflammatory processes were interleukin 17A-driven. Anti-elastin antibodies and T cells specific for elastin peptides were increased in patients with COPD.These data demonstrate that MMP12-generated elastin fragments serve as a self-antigen and drive the cigarette smoke-induced autoimmune processes in mice that result in a bronchitis-like phenotype and airspace enlargement. The study provides proof of concept of cigarette smoke-induced autoimmune processes and may serve as a novel mouse model of COPD.

MTOR Suppresses Cigarette Smoke-Induced Epithelial Cell Death and Airway Inflammation in Chronic Obstructive Pulmonary Disease

Airway epithelial cell death and inflammation are pathological features of chronic obstructive pulmonary disease (COPD). Mechanistic target of rapamycin (MTOR) is involved in inflammation and multiple cellular processes, e.g., autophagy and apoptosis, but little is known about its function in COPD pathogenesis. In this article, we illustrate how MTOR regulates cigarette smoke (CS)-induced cell death, airway inflammation, and emphysema. Expression of MTOR was significantly decreased and its suppressive signaling protein, tuberous sclerosis 2 (TSC2), was increased in the airway epithelium of human COPD and in mouse lungs with chronic CS exposure. In human bronchial epithelial cells, CS extract (CSE) activated TSC2, inhibited MTOR, and induced autophagy. The TSC2-MTOR axis orchestrated CSE-induced autophagy, apoptosis, and necroptosis in human bronchial epithelial cells; all of which cooperatively regulated CSE-induced inflammatory cytokines IL-6 and IL-8 through the NF-κB pathway. Mice with a specific knockdown of Mtor in bronchial or alveolar epithelial cells exhibited significantly augmented airway inflammation and airspace enlargement in response to CS exposure, accompanied with enhanced levels of autophagy, apoptosis, and necroptosis in the lungs. Taken together, these data demonstrate that MTOR suppresses CS-induced inflammation and emphysema-likely through modulation of autophagy, apoptosis, and necroptosis-and thus suggest that activation of MTOR may represent a novel therapeutic strategy for COPD.

Endoplasmic reticulum chaperone GRP78 mediates cigarette smoke-induced necroptosis and injury in bronchial epithelium

Introduction

Bronchial epithelial cell death and airway inflammation induced by cigarette smoke (CS) have been involved in the pathogenesis of COPD. GRP78, belonging to heat shock protein 70 family, has been implicated in cell death and inflammation, while little is known about its roles in COPD. Here, we demonstrate that GRP78 regulates CS-induced necroptosis and injury in bronchial epithelial cells.

Materials and methods

GRP78 and necroptosis markers were examined in human bronchial epithelial (HBE) cell line, primary mouse tracheal epithelial cells, and mouse lungs. siRNA targeting GRP78 gene and necroptosis inhibitor were used. Expression of inflammatory cytokines, mucin MUC5AC, and related signaling pathways were detected.

Results

Exposure to CS significantly increased the expression of GRP78 and necroptosis markers in HBE cell line, primary mouse tracheal epithelial cells, and mouse lungs. Inhibition of GRP78 significantly suppressed CS extract (CSE)-induced necroptosis. Furthermore, GRP78–necroptosis cooperatively regulated CSE-induced inflammatory cytokines such as interleukin 6 (IL6), IL8, and mucin MUC5AC in HBE cells, likely through the activation of nuclear factor (NF-κB) and activator protein 1 (AP-1) pathways, respectively.

Conclusion

Taken together, our results demonstrate that GRP78 promotes CSE-induced inflammatory response and mucus hyperproduction in airway epithelial cells, likely through upregulation of necroptosis and subsequent activation of NF-κB and AP-1 pathways. Thus, inhibition of GRP78 and/or inhibition of necroptosis could be the effective therapeutic approaches for the treatment of COPD.

Efficacy and safety of bronchoscopic lung volume reduction therapy in patients with severe emphysema: a meta-analysis of randomized controlled trials

BACKGROUND

Increasing randomized controlled trials (RCTs) indicate that bronchoscopic lung volume reduction (BLVR) is effective for severe emphysema. In this meta-analysis, we investigated the efficacy and safety of BLVR in patients with severe emphysema.

METHODS

PubMed, Embase and the Cochrane Library and reference lists of related articles were searched, and RCTs that evaluated BLVR therapy VS conventional therapy were included. Meta-analysis was performed only when included RCTs ≥ 2 trials.

RESULTS

In total, 3 RCTs for endobronchial coils, 6 RCTs for endobronchial valves (EBV) and 2 RCTs for intrabronchial valves (IBV) were included. Compared with conventional therapy, endobronchial coils showed better response in minimal clinically important difference (MCID) for forced expiratory volume in 1s (FEV1) (RR = 2.37, 95% CI = 1.61 - 3.48, p < 0.0001), for 6-min walk test (6MWT) (RR = 2.05, 95% CI = 1.18 - 3.53, p = 0.01), and for St. George's Respiratory Questionnaire (SGRQ) (RR = 2.32, 95% CI = 1.77 - 3.03, p < 0.00001). EBV therapy also reached clinically significant improvement in FEV1 (RR = 2.96, 95% CI = 1.49 - 5.87, p = 0.002), in 6MWT (RR = 2.90, 95% CI = 1.24 - 6.79, p = 0.01), and in SGRQ (RR = 1.53, 95% CI = 1.22 - 1.92, p = 0.0002). Both coils and EBV treatment achieved statistically significant absolute change in FEV1, 6MWT, and SGRQ from baseline, also accompanied by serious adverse effects. Furthermore, subgroup analysis showed there was no difference between homogeneous and heterogeneous emphysema in coils group. However, IBV group failed to show superior to conventional group.

CONCLUSIONS

Current meta-analysis indicates that coils or EBV treatment could significantly improve pulmonary function, exercise capacity, and quality of life compared with conventional therapy. Coils treatment could be applied in homogeneous emphysema, but further trials are needed.

Autophagy as a double-edged sword in pulmonary epithelial injury: a review and perspective

Pulmonary epithelial cells form the first line of defense of human airways against foreign irritants and also represent as the primary injury target of these pathogenic assaults. Autophagy is a revolutionary conserved ubiquitous process by which cytoplasmic materials are delivered to lysosomes for degradation when facing environmental and/or developmental changes, and emerging evidence suggests that autophagy plays pivotal but controversial roles in pulmonary epithelial injury. Here we review recent studies focusing on the roles of autophagy in regulating airway epithelial injury induced by various stimuli. Articles eligible for this purpose are divided into two groups according to the eventual roles of autophagy, either protective or deleterious. From the evidence summarized in this review, we draw several conclusions as follows: 1) in all cases when autophagy is decreased from its basal level, autophagy is protective; 2) when autophagy is deleterious, it is generally upregulated by stimulation; and 3) a plausible conclusion is that the endosomal/exosomal pathways may be associated with the deleterious function of autophagy in airway epithelial injury, although this needs to be clarified in future investigations.

Electrophoretic deposition of graphene oxide reinforced chitosan-hydroxyapatite nanocomposite coatings on Ti substrate

Electrophoretic deposition (EPD) is a facile and feasible technique to prepare functional nanocomposite coatings for application in orthopedic-related implants. In this work, a ternary graphene oxide-chitosan-hydroxyapatite (GO-CS-HA) composite coating on Ti substrate was successfully fabricated by EPD. Coating microstructure and morphologies were investigated by scanning electron microscopy, contact angle test, Raman spectroscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. It was found GO-CS surface were uniformly decorated by HA nanoparticles. The potentiodynamic polarization test in simulated body fluid indicated that the GO-CS-HA coatings could provide effective protection of Ti substrate from corrosion. This ternary composite coating also exhibited good biocompatibility during incubation with MG63 cells. In addition, the nanocomposite coatings could decrease the attachment of Staphylococcus aureus.

5-Azacytidine suppresses the proliferation of pancreatic cancer cells by inhibiting the Wnt/β-catenin signaling pathway

5-Azacytidine has been shown to be an effective anti-pancreatic cancer drug, but the mechanism remains unknown. In the current study, we explored the effect of 5-azacytidine on abnormal activation of the Wnt-β-catenin signaling pathway in pancreatic cancer cells. The human pancreatic cancer cell line Bxpc-3 was treated with different concentrations of 5-azacytidine for various times. The proliferation and early apoptosis of the cells were evaluated using the CCK8 method and flow cytometry, respectively. mRNA and protein expression of β-catenin, c-myc, and cyclinD1 were detected using real-time fluorescent quantitative polymerase chain reaction and Western blot analysis, respectively. The proliferation of Bxpc-3 cells was suppressed by 5-azacytidine. The early apoptosis of the cells was significantly enhanced over time and with increasing drug concentrations. The expression of β-catenin, c-myc, and cyclinD1 were down-regulated, showing significant differences between different concentrations and treatment times (P < 0.05). 5-Azacytidine suppressed the proliferation of pancreatic cancer cells by inhibiting the Wnt/β-catenin signaling pathway, particularly the expression of β-catenin, c-myc, and cyclinD1. This study may provide a new potential strategy for diagnosing and treating pancreatic cancer.

Knockdown of RAGE inhibits growth and invasion of gastric cancer cells

The receptor for advanced glycation endproducts (RAGE) is an oncogenic trans-membranous receptor, which is overexpressed in multiple human cancers. However, the role of RAGE in gastric cancer is still elusive. In this study, we investigated the expression and molecular mechanisms of RAGE in gastric cancer cells. Forty cases of gastric cancer and corresponding adjacent non-cancerous tissues (ANCT) were collected, and the expression of RAGE was assessed using immunohistochemistry (IHC) in biopsy samples. Furthermore, RAGE signaling was blocked by constructed recombinant small hairpin RNA lentiviral vector (Lv-shRAGE) used to transfect into human gastric cancer SGC-7901 cells. The expression of AKT, proliferating cell nuclear antigen (PCNA) and matrix metallopeptidase-2 (MMP-2) was detected by Real-time PCR and Western blot assays. Cell proliferative activities and invasive capability were respectively determined by MTT and Transwell assays. Cell apoptosis and cycle distribution were analyzed by flow cytometry. As a consequence, RAGE was found highly expressed in cancer tissues compared with the ANCT (70.0% vs 45.0%, P=0.039), and correlated with lymph node metastases (P=0.026). Knockdown of RAGE reduced cell proliferation and invasion of gastric cancer with decreased expression of AKT, PCNA and MMP-2, and induced cell apoptosis and cycle arrest. Altogether, upregulation of RAGE expression is associated with lymph node metastases of gastric cancer, and blockade of RAGE signaling suppresses growth and invasion of gastric cancer cells through AKT pathway, suggesting that RAGE may represent a potential therapeutic target for this aggressive malignancy.

Monitoring of CaSO(4) deposition behaviors on biofilm during nanofiltration via ultrasonic time-domain reflectometry (UTDR)

The ultrasonic time-domain reflectometry (UTDR) as a non-destructive real-time method was employed to monitor the CaSO(4) deposition behaviors on biofilm during nanofiltration (NF). Two parallel experiments were performed to compare the different behaviors of CaSO(4) deposition with and without biofilm on the membrane. Results showed that the flux decline during combined fouling was slower than that in case of CaSO(4) fouling alone. The Ca(2 + ) rejection obtained with biofilm was higher than that without. A larger acoustic differential signal obtained by UTDR in the combined fouling revealed a denser and thicker layer formed on the membrane surface. Furthermore, the amount of CaSO(4) deposition on the biofouled membrane was more than that on non-biofouled membrane as a result of microorganisms as crystal nucleus to induce CaSO(4) crystallization and deposition. SEM images indicate that the CaSO(4) crystals deposited in order on the non-biofouled membrane, whereas on the biofouled membrane they were embedded in the biofilm. The denser and thicker fouling layer formed with biofilm was impermeable, resulting in a high Ca(2 + ) rejection. The complexation of Ca with polysaccharide in biofilm would eliminate the cake-enhanced osmotic pressure effect leading to a slow flux decline. To sum up, the independent measurements corroborate the ultrasonic measurements.

Amelioration of alkali soil using flue gas desulfurization byproducts: productivity and environmental quality

In this study, flue gas desulfurization (FGD) byproducts are used to ameliorate alkali soil. The average application rates for soils with low exchangeable sodium percentage (ESP), mid ESP, and high ESP are 20.9, 30.6, and 59.3 Mg ha(-1), respectively. The experimental results obtained for 3 consecutive years reveal that the emergence ratios and yields of the crops were 1.1-7.6 times and 1.1-13.9 times those of the untreated control, respectively. The concentrations of Cr, Pb, Cd, As, and Hg in the treated soils are far below the background values stipulated by the Environmental Quality Standard for Soils (GB15618-1995). Their concentrations in the seeds of corn and alfalfa grown in the treated soils are far below the tolerance limits regulated by National Food Standards of China. The results of this research demonstrate that the amelioration of alkali soils using FGD byproducts is promising.

[Enrichment and screening of up-regulated genes of the mosquito Anopheles stephensi in response to malaria parasite]

OBJECTIVE

To isolate and identify genes related to malaria parasite infection in vector mosquito, and to explore the mechanisms.

METHODS

Anopheles stephensi infected with Plasmodium yoelii was used as tester (T) group, while uninfected but normal blood fed as driver (D) one. Engorged female mosquitoes of two groups were collected separately at 24 hours after biting. An enriched subtractive cDNA pool was generated through the course of suppression subtractive hybridization (SSH) and selective PCR amplification. The subtracted library was screened by hybridization using T and D cDNA mixture as probes, respectively. The positive clones, which produced stronger signal when probed with T than with D, were sequenced and their sequence homologues in GenBank database were searched with BLAST by internet.

RESULTS

The analysis of subtraction efficiency showed that the differentially expressed genes in T comparing to in D were enriched significantly. In dot blot screening, 24 of 58 randomly selected clones (41.4%) were shown up-regulation in malaria infected mosquitoes. The BLAST search of 23 genes revealed that 12 were homologous to functionally known genes, 4 were homologous to functionally unknown entries, and 7 were novel without any relatives. Nine of the 23 genes (39.1%) also hit homologous sequences in the An. gambiae EST database generated from an immune competent cell line treated with lipopolysaccharide (LPS).

CONCLUSION

An enriched cDNA pool of the mosquito genes which up-regulated responsively at the early stage of malaria parasite infection was obtained. Expression screening against the pool indicated that various biochemical processes and mechanisms might be involved in the response of mosquito to parasite infection, especially those related with the innate immune system and energy metabolism.

[Partial sequence of sporogony stage-specific 18S ribosomal DNA of Plasmodium yoelii and its application for detection of parasites]

OBJECTIVE

To determine sequence of sporogony stage-specific (S type) 18S ribosomal RNA gene of Plasmodium yoelii (P. y) By265 strain, and by using it to detect the malaria parasites within vector mosquito.

METHODS

A pair of conserved DNA primers, universe primer (Pu) and reverse transcription one (Pr), was designed and synthesized according to sequence of the 18S rRNA gene of Plasmodium berghei (P. b). The segment of the S type 18S rDNA of P. y was amplified by reverse transcript-polymerase chain reaction (RT-PCR) from dissected midguts of Anopheles stephensi infected with P. y on the 7th day after infective blood-meal, and its sequence was then determined. One P. y sporogony stage-specific primer (Pys) was selected according to the sequence. Using this primer and Pr, the parasites within mosquitoes were semi-quantitatively detected through RT-PCR between 1-7 d post-infection.

RESULTS

The length of the amplified segment was 920 bp. Alignment in match region of the 18S rDNA among S type of P. y (PyS), S type of P. b (PbS) and asexual blood stage-specific one of P. y (PyA) revealed that the similarity between the former and the latter two reached 95.3% and 94.0% respectively. The density of amplified band was significantly concordance with the intensity of oocyst in the midgut. Sensitivity of RT-PCR method was higher than that of the traditional dissection and oocyst observation also. The assay could detect the 18S rRNA molecule of the parasites on the third day post-infection while their oocysts were difficult to be recognized under an optical microscope at that time.

CONCLUSION

This S type 18S rDNA sequence in P. y species was first reported (AF266261). As a molecular marker, it could be applied to monitoring the parasite development in its vector at an earlier stage semi-quantitatively with an adequate sensitivity and specificity.

Tissue-specific peptides influence human T cell repertoire to porcine xenoantigens

BACKGROUND

Human CD8+ T cells elicit a vigorous response to allo- or xenogeneic MHC class I molecules. However, the influence of a given MHC-bound peptide to the responding allo- or xenoreactive T cell repertoire is not clear.

METHODS

In this study, we analyzed individual T cell responses to unique tissue epitopes presented on syngeneic porcine endothelial and lymphoblastoid cells by limiting dilution analysis and analyzed the responding T cell repertoire by T cell receptor beta (TCR Vbeta) chain spectrotyping.

RESULTS

Both porcine endothelial and lymphoblastoid cells were able to elicit swine leukocyte antigen (SLA) class I restricted and peptide-dependent cytotoxic T lymphocyte (CTL) responses. The responding human CD8+ T cells showed a heterogenous but limited TCR Vbeta gene usage. Interestingly, although a large portion of the selected TCR Vbeta gene usage in response to endothelial and lymphoblastoid cells were shared (i.e., Vbeta-1, 2, 6.1, 13), unique Vbeta usage was noted in T cells that respond to either endothelial (Vbeta-5.3) or lymphoblastoid cells (Vbeta-5.1, 11), suggesting that porcine tissue-specific epitopes play a role in modulating the responding T cell repertoire. Limiting dilution cloning analysis revealed that a majority (89%) of the CTL clones stimulated by porcine endothelial cells recognized shared peptides presented by both endothelial cells and syngeneic lymphoblastoid cells. However, a significant portion (11%) of the CTL clones recognized unique peptides presented only in the context of SLA class I molecules on endothelial cells.

CONCLUSION

These results provide evidence for the first time that tissue-specific peptides can directly influence T cell repertoire in response to the xenogeneic stimulus.

Induction of apoptosis by cyclo-oxygenase-2 inhibitor NS398 through a cytochrome C-dependent pathway in esophageal cancer cells

Non-steroidal anti-inflammatory drugs (NSAIDs) can induce tumor cells to undergo apoptosis in vitro. They have also shown cancer-preventive activity in vivo. The mechanism of their effects is, however, not well defined. We investigated the mechanism by which a new NSAID, NS398, induces apoptosis in esophageal cancer cell lines. NS398 decreased cell viability in 2 cyclo-oxygenase-2-positive (COX-2(+)) esophageal cancer cell lines but not in a COX-2(-) cell line. DNA fragmentation and TUNEL assays demonstrated that NS398 induced the 2 COX-2(+) cancer cell lines to undergo apoptosis. The percentage of apoptosis induced by NS398 was associated with the level of COX-2 expression. Further investigation showed that the cytochrome c pathway was responsible for NS398-induced apoptosis; i.e., cytochrome c was released from mitochondria, caspase-9 and caspase-3 were activated and finally poly(ADP-ribose)polymerase (PARP) was cleaved. Furthermore, the effect of NS398 was inhibited by the caspase inhibitor Z-DEVD-FMK and prostaglandin E(2). In contrast, bcl-2, bax, c-myc, Fas and Fas-ligand showed minor changes. Altogether, our data suggest that induction of apoptosis by NS398 is associated with COX-2 expression and occurs through the cytochrome c-dependent pathway, which sequentially activates caspase-9 and caspase-3 and cleaves PARP.

Progressive decreases in nuclear retinoid receptors during skin squamous carcinogenesis

Retinoids are essential for normal skin growth, differentiation, and apoptosis and are active pharmacologically in the prevention and treatment of skin cancers and other lesions. Retinoid effects are mediated mainly by retinoic acid receptors (RARs) and retinoid X receptors (RXRs), which act as transcription factors to alter gene expression. Using in situ hybridization, we analyzed the expression of RARs and RXRs in normal sun-exposed skin (n = 85), squamous cell carcinoma (SCC; n = 28), and actinic keratosis [AK (a precursor to SCC); n = 38]. The expressions of five receptors (RAR-alpha and -gamma and RXR-alpha, -beta, and -gamma) were moderate to very strong in normal skin, with higher expressions in spinous and granular layers than in the basal layer. RAR-beta expression was weak or absent in normal and lesion samples. All five receptors expressed in the skin were suppressed progressively from normal skin to premalignant skin (AK) to invasive skin SCC. Specific receptor decreases in lesions relative to normal skin ranged from 75% (RXR-beta) to 96% (RAR-alpha) in SCC and from 37% (RAR-gamma) to 68% (RXR-beta) in AK. The degree of suppression of RXR-alpha and RAR-gamma, the two predominant retinoid receptors in skin, was relatively less for RXR-alpha (58% versus 86%; P = 0.015) and relatively greater for RAR-gamma (37% versus 89%; P = 0.0001) between AK and SCC, suggesting that suppression of RXR-alpha may be an earlier event and expression of RAR-gamma may be a later event of multistep squamous skin carcinogenesis. Our results indicate that suppressed expression of retinoid receptors occurs early (in AK) and is associated with progression of squamous skin carcinogenesis to SCC.

Induction of apoptosis in colon cancer cells by cyclooxygenase-2 inhibitor NS398 through a cytochrome c-dependent pathway

Nonsteroidal anti-inflammatory drugs (NSAIDs) have shown cancer preventive activity in patients who took them frequently. These drugs can induce tumor cells to undergo apoptosis in vitro. NS398, a cyclooxygenase-2 (COX-2)-selective inhibitor, has been reported to cause apoptosis in cancer cell lines. Therefore, we examined its effect on 15 human colon cancer cell lines and investigated its mechanism of action. NS398 decreased cell viability in all of the cell lines. Tumor cells that expressed COX-2 were shown to be more sensitive to NS398 treatment. In three selected colon cancer cell lines, NS398-induced apoptosis was mediated by the release of cytochrome c from mitochondria and, consequently, by the activation of caspase-9 and caspase-3 and by the cleavage of poly(ADP-ribose) polymerase. In contrast, caspase-8 was not involved in NS398-induced apoptosis, which suggested that the cytochrome c pathway may play an important role in NS398-induced apoptosis in colon cancer cell lines. Therefore, the combination of NS398 with apoptosis-inducing drugs through cytochrome c-independent pathways may be warranted.

Cyclooxygenase-2 overexpression is a marker of poor prognosis in stage I non-small cell lung cancer

Cyclooxygenase-2 (COX-2), the enzyme that converts arachidonic acid to prostaglandins, is overexpressed in a variety of different tumors, including those of the colon, pancreas, lung, and head and neck. We used in situ hybridization with a digoxgenin-labeled COX-2 antisense riboprobe to assess the presence of strong or intermediate versus weak or absent COX-2 expression in specimens from 160 patients with stage I non-small cell lung cancer (NSCLC). Of these, 3 specimens had strong expression, 69 had intermediate expression of COX-2, 24 had weak expression, and 64 had no detectable COX-2. The strength of COX-2 expression was associated with a worse overall survival rate (P = 0.001) and a worse disease-free survival rate (P = 0.022). The median survival times for the strong, intermediate or weak, and null COX-2 expressors were 1.04, 5.50, and 8.54 years, respectively. Interestingly, all three specimens with strong COX-2 expression came from patients who died within 18 months. Retinoic acid receptor beta (RAR-beta) is a nuclear retinoid receptor whose expression is frequently lost in aerodigestive tract carcinogenesis. We previously demonstrated that expression of RAR-beta in stage I NSCLC indicates a poor prognosis. Retinoids have been shown to prevent induction of COX-2 by mitogens and tumor promoters. Expression of COX-2 correlated with RAR-beta expression (P = 0.053), but not with k-ras mutational status, vascular endothelial growth factor, basic fibroblast growth factor, interleukin 8 levels, or other markers of angiogenesis, invasion, and metastases. Thus, like RAR-beta positivity, COX-2 overexpression appears to portend a shorter survival among patients with early stage non-small cell lung cancer. Future studies of RAR-beta and COX-2 regulation in NSCLC should further the development of prevention and therapy interventions with retinoids and/or COX-2 antagonists in this patient population.

Differential expression of retinoic acid receptors and p53 protein in normal, premalignant, and malignant esophageal tissues

PURPOSE

Esophageal cancer remains a significant health problem worldwide. The very low 5-year survival rates and rapid increase in the incidence of adenocarcinoma indicate the urgent need for early identification of and new approaches to the prevention and treatment of this cancer.

METHODS

To find biomarkers for early identification of the disease, we analyzed nuclear retinoic retinoid receptor mRNAs, p53 protein, and the proliferation marker Ki 67 in surgical specimens of normal, mildly, and severely dysplastic and malignant esophageal tissues.

RESULTS

Nuclear retinoid receptors (RAR-alpha, RAR-gamma, and RXR-alpha) were expressed in most (79%-100%) normal, dysplastic, and malignant esophageal mucosae, whereas expression of RAR-beta was progressively lost from normal esophagus to carcinoma (84%-54%). In contrast, expression of p53 protein and Ki 67 were dramatically increased in severely dysplastic and cancerous tissues of the esophagus (from 5% to 62%).

CONCLUSIONS

Loss of RAR-beta expression and accumulation of p53 and Ki 67 proteins may serve as biomarkers for esophageal cancer.

Effect of benzo[a]pyrene diol epoxide on expression of retinoic acid receptor-beta in immortalized esophageal epithelial cells and esophageal cancer cells

Expression of retinoic acid receptor-beta (RAR-beta) is frequently lost in tobacco-related cancers. Benzo[a]pyrene diol epoxide (BPDE) is an active metabolite of tobacco procarcinogen benzo[a]pyrene and plays an important role in tobacco carcinogenesis. We therefore exposed SV-40 immortalized esophageal epithelial cells and esophageal cancer cells to BPDE to understand possible interactions between BPDE and RAR-beta expression. Our data showed that BPDE decreased RAR-beta mRNA and protein levels by suppression of transcription of RAR-beta. Retinoic acid was able to partially block the inhibitory effect of BPDE on RAR-beta expression and to increase G1 phase of cell cycles. Furthermore, induction of COX-2 expression by BPDE was associated with RAR-beta inhibition. This study suggests that one way by which BPDE causes esophageal carcinogenesis may be through the inhibition of RAR-beta.

Detection of altered retinoic acid receptor expression in tissue sections using in situ hybridization

Nuclear retinoid receptors mediate retinoid effects in controlling cell growth, differentiation, apoptosis, and carcinogenesis. Altered expression or activity of these receptors could abolish the retinoid signal transduction pathway and be associated with human carcinogenesis. In situ hybridization is a powerful tool for analyzing gene expression in formalin-fixed, paraffin-embedded tissue sections, especially for newly cloned genes or when no antibodies are available. Detection of altered retinoid receptor expression using in situ hybridization in premalignant and malignant tissues has provided important information about the roles of these receptors in cancer development and the response of these tissues to retinoid treatment. Among these receptors, altered expression of retinoic acid receptor-beta (RAR-beta) has been mostly detected in human cancers, including those of the head and neck, lung, esophagus, mammary gland, pancreas, and cervix. RAR-beta is thus currently used as a surrogate endpoint biomarker in different clinical prevention trials of various cancers.

Differential expression of galectin-1 and galectin-3 in benign and malignant salivary gland neoplasms

Galectins are a family of non-integrin beta-galactosidase-binding lectins. Altered expression of galectins has been associated with neoplastic transformation and progression in several human tumors. In this study, we examined the distribution patterns of galectin-1 and galectin-3 in normal (n=45), benign (n=16), and malignant (n=49) salivary gland specimens using immunohistochemistry to determine their diagnostic and/or biological implications in salivary gland tumorigenesis. In normal salivary glands, galectin-3 expression was limited to ductal cells, and galectin-1 was usually faintly detected in ductal cells and strongly positive in myoepithelial cells. In benign tumors, galectin-3 maintained the ductal localization, but galectin-1 showed variable expression in ductal and myoepithelial cells. In malignant tumors, most of the polymorphous low-grade adenocarcinomas and carcinoma ex-pleomorphic adenomas expressed both galectins, whereas adenoid cystic and acinic cell carcinomas showed dramatically reduced galectin-3 expression and heterogeneous galactin-1 staining. Our data demonstrated altered localization and expression of galectin-3, and to lesser extent, galectin-1 in salivary gland carcinomas. These findings may assist in the differential diagnosis of some salivary gland malignancies, especially when using small and limited fine-needle aspiration materials.

Retinoic acid receptor-beta as a prognostic indicator in stage I non-small-cell lung cancer

PURPOSE

Retinoids are pivotal in the growth and differentiation of certain epithelial tissues, interacting with nuclear retinoid receptors (the retinoic acid receptors [RARs] and retinoid X receptors [RXRs]), which function as transcription factors. RAR-beta mRNA is undetectable by in situ hybridization (ISH) in 50% of non-small-cell lung cancers (NSCLC). RAR-beta may suppress tumorigenicity. Therefore, we hypothesized that loss of expression of RAR-beta gene in stage I NSCLC is a prognostic factor of a poor clinical outcome.

PATIENTS AND METHODS

We retrospectively analyzed RAR-beta mRNA levels (by ISH using a digoxigenin-labeled antisense riboprobe) in specimens from 185 consecutive patients with completely resected clinical/radiographic stage I NSCLC for whom clinical follow-up data were available.

RESULTS

One hundred fifty-six patients who met the criteria of pathologic stage I NSCLC and positivity for RXR-alpha mRNA (used as a control to assess RNA degradation) and who had adequate follow-up could be evaluated. RAR-beta mRNA expression was undetectable in 51 patients, weakly positive in 64 patients, and strongly positive in 41 patients. Overall survival of the 41 patients with strongly positive RAR-beta was significantly worse than for the 115 patients with weak or absent RAR-beta (P =.045).

CONCLUSION

Unexpectedly, strong RAR-beta expression was associated with a significantly worse outcome of early-stage NSCLC. The mechanisms underlying this clinically and biologically important finding should be further explored.

Lack of correlation between expression of retinoic acid receptor-beta and loss of heterozygosity on chromosome band 3p24 in esophageal cancer

Loss of heterozygosity (LOH) on chromosome arm 3p occurs frequently in human cancers, including esophageal cancer, suggesting that tumor suppressor genes may be located on this chromosome arm. The retinoic acid receptor-beta (RARB) gene is localized on chromosome band 3p24, and its expression is progressively lost during esophageal carcinogenesis. Furthermore, growth inhibition of esophageal cancer cell lines by all-trans retinoic acid has been associated with the constitutive and induced expression of RARB. We therefore assessed LOH on chromosome arm 3p and RARB expression in esophageal cancer to investigate the mechanism of altered RARB expression during carcinogenesis. We first analyzed LOH in 65 paired surgical specimens of normal mucosa and esophageal cancer by using 10 microsatellite markers, which resulted in 44 informative cases for subsequent study. LOH on chromosome band 3p24 was found to occur at an overall rate of 36.4% (16/44) by three markers (D3S1293, THRB, and D3S1283). LOH for these three individual markers was 14.0%, 47.4%, and 20.9%, respectively. Meanwhile, RARB expression was lost in 43.2% (19/44) of these 44 samples. The loss of RARB expression was not correlated with LOH on chromosome band 3p24 (gamma = -0.22, -0.069, and -0.02, P = 0.15, 0.78, and 0.9 for D3S1293, THRB, and D3S1283, respectively), although both altered RARB expression and LOH in esophageal cancer were statistically significant (P = 0.001 and 0.0001, respectively), indicating that the loss of RARB expression cannot be explained by LOH on 3p24.

Lack of correlation between expression of retinoic acid receptor-beta and loss of heterozygosity on chromosome band 3p24 in esophageal cancer

Loss of heterozygosity (LOH) on chromosome arm 3p occurs frequently in human cancers, including esophageal cancer, suggesting that tumor suppressor genes may be located on this chromosome arm. The retinoic acid receptor-beta (RARB) gene is localized on chromosome band 3p24, and its expression is progressively lost during esophageal carcinogenesis. Furthermore, growth inhibition of esophageal cancer cell lines by all-trans retinoic acid has been associated with the constitutive and induced expression of RARB. We therefore assessed LOH on chromosome arm 3p and RARB expression in esophageal cancer to investigate the mechanism of altered RARB expression during carcinogenesis. We first analyzed LOH in 65 paired surgical specimens of normal mucosa and esophageal cancer by using 10 microsatellite markers, which resulted in 44 informative cases for subsequent study. LOH on chromosome band 3p24 was found to occur at an overall rate of 36.4% (16/44) by three markers (D3S1293, THRB, and D3S1283). LOH for these three individual markers was 14.0%, 47.4%, and 20.9%, respectively. Meanwhile, RARB expression was lost in 43.2% (19/44) of these 44 samples. The loss of RARB expression was not correlated with LOH on chromosome band 3p24 (gamma = -0.22, -0.069, and -0.02, P = 0.15, 0.78, and 0.9 for D3S1293, THRB, and D3S1283, respectively), although both altered RARB expression and LOH in esophageal cancer were statistically significant (P = 0.001 and 0.0001, respectively), indicating that the loss of RARB expression cannot be explained by LOH on 3p24.

Aspirin induction of apoptosis in esophageal cancer: a potential for chemoprevention

The potential use of non-steroidal anti-inflammatory drugs (NSAIDs) in the prevention of gastrointestinal cancers has been highlighted recently. However, it is not known whether NSAIDs could also be useful for preventing esophageal cancer, although regular users of these drugs appear to have a decreased incidence of esophageal cancer. Therefore, we examined the effect of aspirin on growth and apoptosis in 10 esophageal cancer cell lines as well as the expression and modulation of its target enzymes, cyclooxygenases (COXs), and their product prostaglandin E2. Growth inhibition of these cells by aspirin was dose- and time-dependent and associated with the induction of apoptosis. COX-1 and COX-2 were expressed in 7 of the 10 cell lines. Bile acids could induce COX-2 expression in six of eight cell lines tested, which was correlated with prostaglandin E2 production, and aspirin could inhibit COX-2 enzymatic activity even after bile acid stimulation but was unable to change the COX-2 protein level in these cell lines. Down-regulation of bcl-2 by aspirin was found in the two cell lines tested. These results suggest that induction of apoptosis by aspirin may be a mechanism by which it can intervene in esophageal carcinogenesis and may be indicative of the potential of NSAIDs as chemopreventive agents in esophageal cancer.

Expression of E-cadherin is associated with squamous differentiation in squamous cell carcinomas

E-cadherin is a cell surface molecule that mediates cell-cell adhesion in normal epithelium. Disabled or aberrant E-cadherin expression increases cell motility and promotes the transition of well-differentiated adenoma to invasive carcinoma. To evaluate whether E-cadherin could serve as a biomarker of squamous cell differentiation, we analyzed its expression by immunohistochemistry in formalin-fixed, paraffin-embedded tissue sections of 7 head and neck cancer patients, 19 lung cancer patients, 73 esophageal cancer patients, 19 skin cancer patients, and 18 cervical cancer patients. E-cadherin was expressed at very high levels (93%-100%) in adjacent or distant normal squamous epithelia. Likewise, most (75-100%) well-differentiated squamous cell carcinomas (SCCs) also expressed E-cadherin. In contrast, poorly differentiated SCCs expressed less than 40% of E-cadherin. Furthermore, immunohistochemical analysis showed that the differentiation-inducing agent, all-trans retinoic acid, can up-regulate E-cadherin expression in esophageal SCC cells in vitro. Our data demonstrated that E-cadherin expression is associated with SCC differentiation and that may serve as a squamous cell differentiation marker.

Predicting cancer development in oral leukoplakia: ten years of translational research

Our 10-year translational study of the oral premalignant lesion (OPL) model has advanced the basic understanding of carcinogenesis. Although retinoids have established activity in this model, a substantial percentage of our OPL patients progress to cancer, especially after treatment is stopped. On the basis of our 10-year OPL study, we have developed the first comprehensive tool for assessing cancer risk of OPL patients. This cancer risk assessment tool incorporates medical/demographic variables, epidemiological factors, and cellular and molecular biomarkers. Between 1988 and 1991, 70 advanced OPL patients were enrolled in a chemoprevention trial of induction with high dose isotretinoin (1.5 mg/kg/day for 3 months) followed by 9 months of maintenance treatment with either low dose isotretinoin (0.5 mg/kg/day) or beta-carotene (30 mg/d; total treatment duration, 1 year). We assessed the relationship between cancer risk factors and time to cancer development by means of exploratory data analysis, logrank test, Cox proportional hazard model, and recursive partitioning. With a median follow-up of 7 years, 22 of our 70 patients (31.4%) developed cancers in the upper aerodigestive tract following treatment. The overall cancer incidence was 5.7% per year. The most predictive factors of cancer risk are OPL histology, cancer history, and three of the five biomarkers we assessed (chromosomal polysomy, p53 protein expression, and loss of heterozygosity at chromosome 3p or 9p). In the multivariable Cox model, histology (P = 0.0003) and the combined biomarker score of chromosomal polysomy, p53, and loss of heterozygosity (P = 0.0008) are the strongest predictors for cancer development. Retinoic acid receptor beta and micronuclei were not associated with increased cancer risk. We have demonstrated a successful strategy of comprehensive cancer risk assessment in OPL patients. Combining conventional medical/demographic variables and a panel of three biomarkers can identify high risk patients in our sample. This result will need to be validated by future studies. With the identification of high risk individuals, more efficient chemoprevention trials and molecular targeting studies can be designed.

Differential binding activities of lectins and neoglycoproteins in human testicular tumors

Testicular germ-cell tumors, a morphologically and clinically diverse group of malignancies provide an ideal model for investigating the biology of glycoconjugates because the biosynthesis of oligosaccharide chains of glycoproteins monitored by plant/invertebrate lectins often changes during tumorigenesis, tumor progression, and metastasis. To investigate such changes in germ-cell tumors, we analyzed 67 surgical specimens from 31 seminomas, 32 embryonic carcinomas, and four choriocarcinomas using glyco- and immunohistochemistry that involved five plant/invertebrate lectins, 16 neoglycoproteins, and galectin-1 antibody. The results showed that some of these markers, such as melibiose-, lactose-, and beta-N-acetylgalactosamine-BSA-biotin were clearly differentially expressed amongst these tumors and between primary and metastatic embryonic carcinomas. The differences in staining for positivity, intensity, and heterogeneity indicate that the differential display of glycoconjugates in tumor cells may be important in tumor growth, metastasis, or prognosis because subtypes of these tumors behave quite differently from one another. Furthermore, we also found identical staining for positivity between most neoglycoproteins and their corresponding lectins, though the staining intensity of neoglycoproteins was weaker. This suggests that neoglycoproteins may be useful markers to replace their plant lectins.

Differential expression of nuclear retinoid receptors in normal and malignant prostates

PURPOSE

To determine (1) whether nuclear retinoic acid receptors (RARs) and retinoid X receptors (RXRs) are differentially expressed in normal and in cancerous human prostate tissues and (2) whether oral fenretinide therapy impacts the expression of these receptors in prostate cancer.

PATIENTS AND METHODS

In situ hybridization with antisense riboprobes was used to probe for RAR and RXR transcripts in prostate tissues in a two-phased study: (1) expression of retinoid receptors in eight normal prostates was compared with their expression in 10 randomly picked radical prostatectomy specimens (group A); (2) expression of retinoid receptors was determined in 22 radical prostatectomy specimens from participants in a clinical study (group B). Twelve patients received oral fenretinide 200 mg/d, and 10 received placebo pills for 28 days before surgery.

RESULTS

RARalpha, RARgamma, RXRalpha, and RXRgamma mRNAs were detected in most normal and cancerous prostates. In group A, RARbeta mRNA was expressed in only four of 10 malignant prostates but was present in seven of eight benign prostates (P =.05). RXRbeta mRNA was expressed in four of eight benign prostates and in zero of 10 malignant prostates (P =.023). In group B prostates, RARbeta and RXRbeta mRNAs were markedly reduced in all cancers and in the adjacent, nonmalignant tissue. There were no differences between receptor expression in the fenretinide-treated group and the placebo group.

CONCLUSION

RARbeta and RXRbeta mRNAs are selectively lost in both prostate cancer and adjacent morphologically normal prostatic tissue, supporting the concept of a field of carcinogenesis. One month of oral fenretinide (200 mg/d) did not influence the expression of retinoid receptors in prostate cancer.

HLA-E and HLA-G expression on porcine endothelial cells inhibit xenoreactive human NK cells through CD94/NKG2-dependent and -independent pathways

Human NK cells contribute a significant role to host defense as well as xenogeneic cytotoxicity. Previous studies using human 721.221 cell line have shown that peptides derived from the leader sequence of the HLA-G binds and up-regulates the surface expression of HLA-E molecules, which was considered to consequently provide negative signals to human NK cells. However, the direct role of HLA-G in inhibiting human NK cells remains controversial. In this study, we showed that the expression of HLA-G or HLA-E in porcine endothelial cells directly protected sensitive porcine cells from human NK cell-mediated xenogeneic cytotoxicity. Ab blocking assays using F(ab')2 of the HLA class I-specific mAb PA2.6 indicated that the protection was directly mediated by the expression of HLA-G and HLA-E on the porcine cells. The HLA-E-mediated protection was blocked by anti-human CD94 Ab. In addition, the engagement of HLA-E lead to the phosphorylation of the CD94/NKG2 complex and the recruitment of SH2 domain-containing protein phosphatase 1 (SHP-1) to the complex. Therefore, HLA-E protected porcine cells from xenoreactive human NK cells through a CD94/NKG2-dependent pathway. In contrast, HLA-G inhibited human NK cells in the absence of CD94/NKG2 phosphorylation or SHP-1 recruitment, and the inhibition was not blocked by anti-CD94 Ab. Therefore, HLA-G protected porcine cells from human NK cells through a CD94/NKG2-independent pathway. These results demonstrated that both HLA-E and HLA-G could directly inhibit human NK cells in the absence of other endogenous HLA class I molecules. These results also have practical implications in preventing xenograft rejection mediated by human NK cells.

Loss of retinoic acid receptor-beta expression is an early event during esophageal carcinogenesis

We recently observed that growth inhibition of esophageal cancer cells by retinoic acid (RA) was associated with both constitutive expression and RA-induced up-regulation of RA receptor beta (RAR-beta). Cell lines that did not express RAR-beta were also resistant to RA. To explore the expression of RAR-beta mRNA in vivo, we analyzed esophageal tissue specimens from 16 normal mucosae, 30 dysplastic lesions, and 157 esophageal tumors by in situ hybridization. RAR-beta was detected in 88% (14/16) of normal esophageal tissues and in 96% (96/100) of distant normal esophageal mucosa from cancer specimens. In contrast, RAR-beta was expressed in only 57% (17/30) of dysplastic lesions and in 54% (84/157) of carcinomas. Among esophageal carcinomas RAR-beta mRNA was expressed in 62% (26/42) of well-differentiated, 54% (27/50) of moderately differentiated, and only 29% (4/14) of poorly differentiated SCCs. Our data suggest that the loss of RAR-beta expression is an early event associated with esophageal carcinogenesis and the status of squamous differentiation.

Galectin-1 and galectin-3 expression in human prostate tissue and prostate cancer

Galectin-1 and galectin-3, two beta-galactoside-binding proteins, have been suggested to play a role in the development and progression of cancer. We have studied the expression of these molecules in normal human prostate tissue and prostate adenocarcinoma. Immunohistochemistry was used to examine formalin-fixed, paraffin-embedded sections of seven normal human prostates, eight cases of prostatic intraepithelial neoplasia (PIN), 20 primary adenocarcinomas of the prostate, and 12 prostate cancer metastases. Galectin-1 was expressed in most cases of all four histologic types. In contrast, galectin-3 expression was significantly decreased in primary carcinoma and metastatic disease compared with normal and premalignant tissue. Galectin-3 expression in primary tumors tended to be less than that of surrounding normal glands. We conclude that loss of galectin-3 expression may be associated with the progression of prostate cancer.

Allele-specific and peptide-dependent recognition of swine leukocyte antigen class I by human cytotoxic T-cell clones

BACKGROUND

The T-cell mediated immune responses play a major role in xenograft rejection. However, the mechanisms behind human T-cell recognition of porcine xenoantigens remain to be elucidated.

METHODS

Human CD8+ T-cell lines were generated against porcine aortic endothelial cells (PAECs) from y/y and z/z haplotypes of Yucatan inbred swine. T-cell clones were obtained by limiting dilution. The human T-cell receptor (TCR)-swine leukocyte antigen (SLA) class I interaction was characterized.

RESULTS

The human CD8+ T-cell mediated direct recognition of PAECs was SLA haplotype-specific. The haplotype specificity was restricted by the SLA class I allelic polymorphism. To characterize the role of SLA-bound peptides in the human TCR-SLA class I interaction, we stripped peptides from SLA molecules by a brief acid treatment. Using z/z-specific CD8+ T cells as effectors, we demonstrated that the acid-treatment, which stripped SLA molecules of bound peptides, decreased the lysis of PAECs by 72%. Addition of peptides eluted from affinity purified z/z SLA class I molecules, but not from the irrelevant y/y SLA class I, restored the lysis of acid-treated z/z PAECs. In addition, the lysis of a human HLA class I negative cell line, 721.221, transfected with a relevant SLA class I allele derived from the z/z haplotype, was significantly increased with the addition of relevant z/z peptides. These experiments indicated that both SLA class I and bound peptides were required for recognition by human CD8+ T cells. Cloning studies identified two groups of xenoreactive T-cell clones. Group I clones recognized distinct porcine peptides in the context of SLA class I molecules, whereas group II clones recognized human endogenous cross-reactive peptides presented by SLA class I.

CONCLUSIONS

Our results demonstrated that, despite the differences in MHC molecules between species, human T-cell recognition of porcine MHC is similar to direct allo-recognition, that is, human TCR recognizes xenogeneic SLA-peptide complexes.

Analysis of variable region of T-cell receptor beta chain usage in the human anti-porcine xenoresponse

BACKGROUND

The human xenoreactive T-cell receptor (TCR) repertoire is not well documented. The aim of this study was to analyze the TCR repertoire in human anti-porcine xenoresponses.

METHODS

Peripheral blood lymphocytes (PBLs) from healthy donors were used to generate human T-cell lines against two different haplotypes of inbred Yucatan miniature swine (y/y and z/z). The variable region of TCR beta-chain (Vbeta) gene usage was determined by fluorescence CDR3 spectrotyping.

RESULTS

TCR Vbeta usage of an established human antiporcine T-cell line analyzed at weeks 5, 7, and 9 showed a sequential increase in Vbeta 1, 2, 6.2, 11, and 19 as compared to unprimed peripheral blood lymphocytes, whereas the usage of other Vbetas decreased. The selection of limited Vbeta genes correlated with the sequential increase in the specific lysis of the T-cell line, suggesting a non-random clonal selection and expansion of T-cell clones that recognized porcine targets. Different Vbeta restriction was found using the same peripheral blood lymphocytes against a different haplotype of swine, indicating this selection of Vbeta gene was swine leukocyte antigen-dependent.

CONCLUSIONS

There is restricted TCR Vbeta usage in the human anti-porcine response, suggesting that a limited number of xenogeneic epitopes are recognized by human T cells. The selection of particular TCR Vbeta clonotypes depends on the swine leukocyte antigen background.

Nuclear retinoid acid receptor beta in bronchial epithelium of smokers before and during chemoprevention

BACKGROUND

Retinoids can reverse neoplastic lesions and prevent second primary tumors in the aerodigestive tract. These effects are thought to be mediated by nuclear retinoic acid receptors (RARs) and retinoid X receptors (RXRs), each receptor group including three subtypes (alpha, beta, and gamma). Previously, we found that RARbeta expression was suppressed in lung cancer. In this study, we investigated whether expression of RARbeta is modulated by chemopreventive intervention.

METHODS

Using in situ hybridization, we analyzed RARbeta messenger RNA (mRNA) expression in bronchial biopsy specimens from heavy smokers, at baseline and after 6 months of treatment with 13-cis-retinoic acid (13-cis-RA) or placebo. Since we had previously detected RARbeta expression in 90% of bronchial specimens from nonsmokers, we considered loss of RARbeta mRNA expression in at least one of six biopsy specimens at baseline in this study to be aberrant.

RESULTS

RARbeta mRNA expression was aberrant in 30 (85.7%) of 35 subjects in the 13-cis-RA group and in 24 (72.7%) of 33 subjects in the placebo group. After 6 months of 13-cis-RA treatment, the number of subjects who were RARbeta positive in all six biopsy specimens increased from five of 35 to 13 of 35 (2.6-fold), so that the percentage of individuals with aberrant RARbeta expression decreased to 62.9% (22 of 35), which represents a statistically significant difference from baseline expression (two-sided P =.01). In the placebo group, no statistically significant difference in RARbeta expression was observed between baseline and 6 months. RARbeta expression was not related to current smoking status or reversal of squamous metaplasia.

CONCLUSIONS

These results indicate that RARbeta is an independent marker of response to 13-cis-RA and may serve as an intermediate biomarker in chemoprevention trials of upper aerodigestive tract cancers.

Up-regulation of retinoic acid receptor beta expression in renal cancers in vivo correlates with response to 13-cis-retinoic acid and interferon-alpha-2a

Retinoic acid receptor-beta (RAR-beta) mRNA is not expressed by retinoid-resistant renal cancer cell lines but is present in retinoid-sensitive SK-RC-06 renal cancer cells and increases following incubation with retinoic acid (RA), suggesting that the antitumor action of RA is mediated through RAR-beta (A. D. Hoffman et al., Clin. Cancer Res., 2: 1077-1082, 2996). To determine whether RAR-beta expression correlates in vivo with major clinical response to patients with renal cell carcinoma (RCC) who were treated with retinoid-based therapy, we used in situ hybridization to analyze RAR-beta expression in tumor specimens obtained from patients who were treated on a clinical trial with 13-cis-RA and IFN-alpha. Thirty-three tissue specimens were analyzed (23 pretreatment and 10 on-treatment). mRNA expression was based on staining intensity, with scores within tumor cells ranging from 0 to 2, where a score of 0 indicated absence of staining, a score of 1 indicated weak staining, and a score of 2 indicated strong staining. RAR-beta expression was present in 22 of 23 (96%) pretreatment and 9 of 10 (90%) on-treatment specimens. Pretreatment levels of expression did not associate with the site of biopsy and did not predict for major clinical response to RA plus IFN-alpha therapy (two-sided Fisher's exact test, P = 0.826). However, an increase in the intensity of RAR-beta mRNA expression was detected in four of five (80%) patients who achieved a major response but in none of the five patients with progressive disease in whom sequential biopsies were available (two-sided Fisher's exact test, P = 0.048). These data show that RAR-beta transcripts increase in tumor cells of RCC patients who clinically respond to retinoid-based therapy. Retinoids that potently induce RAR-beta expression should be evaluated in the treatment of advanced RCC.

Decreased expression of retinoic acid receptors, transforming growth factor beta, involucrin, and cornifin in cervical intraepithelial neoplasia

Cervical intraepithelial neoplasia (CIN) I, II, and III represent a spectrum of premalignant epithelial changes and are ideal targets for application of chemoprevention strategies. Intermediate end point biomarkers are increasingly being used as surrogate end points to monitor clinical chemoprevention trials. To identify potential biomarkers in cervical epithelium, we analyzed the expression of nuclear retinoic acid receptor (RAR) mRNA by in situ hybridization, involucrin, cornifin, and transforming growth factors (TGFs) beta1 and beta2 by immunohistochemistry in cervical specimens, which contained adjacent normal epithelium and CIN lesions from 52 patients. These biomarkers were expressed in all adjacent normal cervical epithelia, whereas all CIN lesions including CIN I, CIN II, and CIN III exhibited decreased expression of RAR-alpha by 55.8%, RAR-beta by 64.7%, RAR-gamma by 54.9%, involucrin by 80.8%, cornifin by 88.5%, TGF-beta1 by 89.7%, and TGF-beta2 by 85.7%. Viewed as a whole, these biomarkers were down-regulated in 100% of the CIN lesions. Because all of these biomarkers can be modulated in vitro by retinoids, they may serve as intermediate biomarkers for retinoid chemoprevention trials in the patients with CIN lesions.

Expression and up-regulation of retinoic acid receptor-beta is associated with retinoid sensitivity and colony formation in esophageal cancer cell lines

Retinoids exhibit chemotherapeutic and chemopreventive activities, possibly due to their ability to modulate cell growth, differentiation, and apoptosis. These effects are thought to be mediated by nuclear retinoic acid (RA) receptors (RARs) and retinoid X receptors, each of which includes three subtypes (alpha, beta, and gamma) that act as transcription factors. To determine whether RARs play a role in mediating the effects of RA on human esophageal cancer (HEC) cells, we analyzed the effects of RA on: (a) the growth, differentiation, and apoptosis in seven HEC cell lines; (b) receptor expression; (c) receptor modulation by RA; and (d) expression of receptors in 20 surgical HEC specimens. RA inhibited the growth of five of seven cell lines and also the constitutive expression of the squamous differentiation markers cytokeratin 1 and transglutaminase I in all cell lines. The growth inhibition by RA was due to the induction of apoptosis in the five cell lines. All seven cell lines expressed RAR-alpha and RAR-gamma, and four cell lines showed some changes by RA, but not associated with apoptosis. In contrast, RAR-beta was expressed in five of seven cell lines and up-regulated by RA in these five cell lines, which were associated with apoptosis. Two cell lines that failed to express RAR-beta showed no growth inhibition or apoptosis and no RAR-beta inducibility. Interestingly, only these two cell lines were able to form colonies in soft agar. RAR-alpha, RAR-beta, and RAR-gamma mRNAs were expressed in all 20 adjacent normal esophageal tissues. The expression of RAR-alpha and RAR-gamma remains positive in HEC specimens, but RAR-beta expression was detected in only 6 of 20 HEC specimens. These data suggest that the expression of RAR-beta is associated with response of HEC cells to RA and that the loss of RAR-beta expression may be associated with HEC development.