[Clinicopathological features of SMARCA4-deficient lung adenocarcinoma: a study of 42 cases]

Objective: To investigate the clinicopathological characteristics and genetic mutations of SMARCA4-deficient lung adenocarcinoma. Methods: From January 2021 to April 2023 in the First Affiliated Hospital of Zhengzhou University, 42 cases of SMARCA4-deficienct lung adenocarcinoma were diagnosed and now analyzed. All cases were retrospectively studied using hematoxylin-eosin staining and immunohistochemistry. The clinicopathological features were reviewed. Next-generation sequencing (NGS) was performed to investigate the mutations of related genes. Results: Among the 42 cases, there were 35 biopsy and 7 surgical specimens. There were 38 males and 4 females. The male to female ratio was 9.5∶1.0, with an age range from 42 to 78 years. Thirty-three patients were smokers. Overall, 4 cases (9.5%), 2 cases (4.7%), 18 cases (42.9%) and 18 cases (42.9%) were at stages Ⅰ, Ⅱ, Ⅲ, and Ⅳ, respectively. Microscopically, all the cases were non-mucinous adenocarcinoma, without lepidic pattern. The morphology was diverse. Rhabdomyoid cells, tumor giant cells and tumor necrosis were present. Most of the tumor cells had eosinophilic cytoplasm and occasionally clear cytoplasm. Defined cell borders and variable cytoplasmic hyaline secretory globules could be found. Inflammatory cells infiltrated the tumor stroma. Immunohistochemistry showed 29 cases (69.0%, 29/42) expressed TTF1, 10 cases (40.0%, 10/25) expressed Napsin A, and 20 cases (100.0%, 20/20) expressed INI1. Forty cases (95.2%, 40/42) showed BRG1 loss in all tumor cells, while 2 cases (4.8%, 2/42) had partial BRG1 loss. PD-L1 (22C3) was positive in 59.2% of the cases (16/27). NGS revealed mutations in EGFR, ROS1, MET, RET and KRAS. Six cases (6/8) showed SMARCA4 mutation, while some cases were accompanied by mutations of TP53 (7/15), STK11 (4/8), and KEAP1 (1/8). Driver gene mutations were more common in women (P<0.05). Patients were followed up for 1-25 months. Four patients died and 20 patients' diseases progressed. Conclusions: SMARCA4-deficient lung adenocarcinoma lacks characteristic morphology. Most of them express TTF1 and harbor driver gene mutations. It is necessary to identify this subset of lung adenocarcinoma by carrying out BRG1 stain routinely on lung adenocarcinoma. These patients can then be identified and benefit from targeted therapies.

[Analysis of clinical features and etiological diagnostic indices of reproductive age women with hyperandrogenism]

Objective: To investigate the clinical features and the value of different diagnostic indices for etiology in reproductive age women with hyperandrogenism. Methods: The medical records of 96 reproductive age women with hyperandrogenism in the multi-disciplinary team of Peking University First Hospital from January 2020 to April 2021 were collected. The patients were divided into four groups based on final diagnosis: congenital adrenal hyperplasia (CAH) (n=8), polycystic ovary syndrome (PCOS) (n=67), idiopathic hyperandrogenism (n=13) and other specific diseases (n=8), respectively. The indices related to androgens in different groups were compared, and then their efficiency for diagnosis of CAH and PCOS were analyzed with receiver operator characteristic curve (ROC curve). Results: A total of 96 patients with hyperandrogenism were recruited, with the age of 19-45 (29±6) years old. Overall, 4.2% (4/96) of the patients were with single clinical hyperandrogenism, 56.3% (54/96) were with single laboratory hyperandrogenaemia and 39.6% (38/96) were with both. The breakdown into laboratory hyperandrogenaemia subtypes was as follows: only T elevation 22.8% (21/92), only A2 elevation 7.6% (7/92), none DHEAS elevation, only FAI elevation 5.4% (5/92) and elevation of more than one of the androgen indices mentioned above accounted for 64.1% (59/92). In the reasons of consultation, simple irregular menstruation (36.0%, 32/89) or accompanied by clinical hyperandrogenism with or without infertility (36.0%, 32/89) were the most common. As for primary visiting departments, Obstetrics and Gynecology accounted for 53.2% (51/96), and then Endocrinology as 39.5% (38/96). The 17-OHP level of CAH, PCOS and idiopathic hyperandrogenism group was 20.0 (8.2, 33.1), 1.1 (0.8, 1.4), 0.9 (0.8, 1.3) ng/ml, respectively. The androstenedione level in these groups was 6.3 (4.6, 8.7), 3.8 (2.9, 4.8) and 3.2 (2.7, 3.7) ng/ml, respectively. The 17-OHP and androstenedione levels of CAH group were significantly higher than that in PCOS or idiopathic hyperandrogenism group (all P<0.05). The ratio of LH and FSH in these three groups was 0.8(0.5, 1.0), 1.3(0.6, 1.9) and 0.6(0.3, 0.7), respectively. The ratio of LH and FSH was significantly higher in PCOS than that in idiopathic hyperandrogenism group (P=0.024), but yet there was no significant difference compared with CAH group (P>0.05). The AUC of ROC curve of 17-OHP for CAH diagnosis was 0.94, followed by androstenedione 0.83, whereas LH/FSH for PCOS diagnosis was only 0.63. Conclusions: Among the reasons of consultation in reproductive age women who visited our multi-disciplinary team for female hyperandrogenism, simple irregular menstruation or accompanied by clinical hyperandrogenism with or without infertility are the most common. PCOS accounts for the majority of different androgen excess disorders. 17-OHP is the most valuable parameter for the diagnosis of CAH and secondly androstenedione.

[MicroRNA-140-5p suppresses cell proliferation and invasion in esophageal squamous cell carcinoma by targeting Glut1]

Objective: To investigate the expression of microRNA-140-5p (miR-140-5p) in esophageal squamous cell carcinoma (ESCC) and its role in cell proliferation and invasion of ESCC. Methods: Real-time quantitative PCR (qPCR) was used to detect the expression levels of miR-140-5p in ESCC tissues and cells. Negative control and miR-140-5p mimic were transfected into Eca109 and KYSE70 cells. CCK-8 kit and Transwell assay were employed to examine the changes of cell proliferation and invasion ability after transfection, respectively. The dual-luciferase reporter assay was used to assess the interaction of miR-140-5p with Glut1. Western blot was utilized to detect the Glut1 protein expression after transfection. Results: Analysis of the related GEO datasets revealed that the expression of miR-140-5p in ESCC tissues was significantly lower than that in normal tissues (P<0.01). The qPCR testing demonstrated that the expression of miR-140-5p in ESCC tissues and cells was markedly lower than that in normal tissues and normal esophageal epithelial cell Het-1A (P<0.01). The miR-140-5p expression was closely associated with tumor differentiation, TNM staging and lymph node metastasis in ESCC patients. The survival rate of ESCC patients with high miR-140-5p level was higher than those with low miR-140-5p level (P<0.05). Besides, addition of miR-140-5p mimic significantly upregulated the expression of miR-140-5p in Eca109 and KYSE70 cells, and suppressed cell proliferation and invasion in Eca109 and KYSE70 cells. The dual-luciferase reporter assay showed that Glut1 was a direct target of miR-140-5p in ESCC cells, and its expression was upregulated in ESCC tissues. Glut1 expression was inversely associated with miR-140-5p expression in ESCC tissues. MiR-140-5p mimic dramatically inhibited the expression of Glut1 in Eca109 and KYSE70 cells. Conclusions: MiR-140-5p plays an essential role in ESCC development and progression. Targeting at miR-140-5p/Glut1 may be a novel therapeutic strategy for ESCC patients.

The molecular architecture of photoreceptor phosphodiesterase 6 (PDE6) with activated G protein elucidates the mechanism of visual excitation

Photoreceptor phosphodiesterase 6 (PDE6) is the central effector of the visual excitation pathway in both rod and cone photoreceptors, and PDE6 mutations that alter PDE6 structure or regulation can result in several human retinal diseases. The rod PDE6 holoenzyme consists of two catalytic subunits (Pαβ) whose activity is suppressed in the dark by binding of two inhibitory γ-subunits (Pγ). Upon photoactivation of rhodopsin, the heterotrimeric G protein (transducin) is activated, resulting in binding of the activated transducin α-subunit (Gt_α) to PDE6, displacement of Pγ from the PDE6 active site, and enzyme activation. Although the biochemistry of this pathway is understood, a lack of detailed structural information about the PDE6 activation mechanism hampers efforts to develop therapeutic interventions for managing PDE6-associated retinal diseases. To address this gap, here we used a cross-linking MS-based approach to create a model of the entire interaction surface of Pγ with the regulatory and catalytic domains of Pαβ in its nonactivated state. Following reconstitution of PDE6 and activated Gt_α with liposomes and identification of cross-links between Gt_α and PDE6 subunits, we determined that the PDE6-Gt_α protein complex consists of two Gt_α-binding sites per holoenzyme. Each Gt_α interacts with the catalytic domains of both catalytic subunits and induces major changes in the interaction sites of the Pγ subunit with the catalytic subunits. These results provide the first structural model for the activated state of the transducin-PDE6 complex during visual excitation, enhancing our understanding of the molecular etiology of inherited retinal diseases.

Allosteric Regulation of Rod Photoreceptor Phosphodiesterase 6 (PDE6) Elucidated by Chemical Cross-Linking and Quantitative Mass Spectrometry

Photoreceptor phosphodiesterase (PDE6) is the central effector enzyme in the visual excitation pathway in rod and cone photoreceptors. Its tight regulation is essential for the speed, sensitivity, recovery, and adaptation of visual signaling. The rod PDE6 holoenzyme (Pαβγ₂) is composed of a catalytic heterodimer (Pαβ) that binds two inhibitory γ subunits. Each of the two catalytic subunits (Pα and Pβ) contains a catalytic domain responsible for cGMP hydrolysis and two tandem GAF domains, one of which binds cGMP noncatalytically. Unlike related GAF-containing PDEs where cGMP binding allosterically activates catalysis, the physiological significance of cGMP binding to the GAF domains of PDE6 is unknown. To elucidate the structural determinants of PDE6 allosteric regulators, we biochemically characterized PDE6 complexes in various allosteric states (Pαβ, Pαβ-cGMP, Pαβγ₂, and Pαβγ₂-cGMP) with a quantitative cross-linking/mass spectrometry approach. We employed a normalization strategy to dissect the cross-linking reactivity of individual residues in order to assess the spatial cross-linking propensity of detected pairs. In addition to identifying cross-linked pairs that undergo conformational changes upon ligand binding, we observed an asymmetric binding of the inhibitory γ-subunit and the noncatalytic cGMP to the GAFa domains of rod PDE6, as well as a stable open conformation of Pαβ catalytic dimer in different allosteric states. These results advance our understanding of the exquisite regulatory control of the lifetime of rod PDE6 activation/deactivation during visual signaling, as well as providing a structural basis for interpreting how mutations in rod PDE6 subunits can lead to retinal diseases.

[Tracheobronchopathia osteochondroplastica: a clinicopathological analysis of 18 cases]

Objective: To investigate the clinical symptoms, imaging features, pathologic manifestations and diagnosis of tracheobronchopathia osteochondroplastica (TO). Methods: The clinical data, imaging and pathologic features and outcome of 18 TO patients diagnosed at the First Affiliated Hospital of Zhengzhou University from August 2011 to August 2018 were collected and analyzed. Results: The 18 TO patients included 10 males and 8 females; patients' age range was 31 to 64 years (mean 52 years). Six patients (6/18) were smokers. The main presenting clinical symptoms included cough in 15 cases, expectoration in eight cases (8/18), hemoptysis in five cases (5/18), chest tightness in four cases, wheezing in three cases and chest pain in two cases. The time interval between the initial symptoms and diagnosis was 1.5 to 360.0 months, and the average time interval was 45.2 months. Blood calcium and phosphorus were normal in 18 patients (18/18). Chest X-ray showed no direct evidence of TO. Six patients (6/18) showed irregular changes in the trachea or bronchial wall by chest CT scan. Three patients (3/18) had mild ventilatory obstruction. TO was classified as: 10 cases (10/18) were scattered type, seven cases (7/18) were diffuse type and one case (1/18) was confluent type. Epithelial squamous metaplasia, submucosal cartilage, submucosal ossification and hematopoietic bone marrow within the ossified areas were the characteristic histopathologic findings of TO. Conclusions: TO is a rare benign disorder that shows atypical presentation. CT scan is insensitive, the histopathology shows submucosal cartilage or ossification. TO should be diagnosed by comprehensive consideration of clinical symptoms, imaging and pathology.

[Clinicopathological features and prognostic factors of primary pulmonary adenoid cystic carcinoma: a study of 59 cases]

Objective: To investigate the clinicopathological features and prognostic indicators of primary pulmonary adenoid cystic carcinoma. Methods: Fifty-nine cases of primary pulmonary adenoid cystic carcinoma were collected from August 2011 to December 2017 at the First Affiliated Hospital of Zhengzhou University. All cases were retrospectively studied by hematoxylin-eosin staining and immunohistochemistry. The clinicopathological features were reviewed and patient survival analysis was performed using Kaplan-Meier method and Cox regression model. Status of epidermal growth factor receptor (EGFR), KRAS, BRAF genes was analyzed in 15 of the 59 study cases. Results: Among 59 cases, there were 25 males and 34 females with male to female ratio of 1.0 to 1.4. The patient age ranged from 29 to 81 years with a mean age of 55 years. The tumor max diameters ranged from 1.0 to 9.6 cm with an average diameter of 2.8 cm. Fifteen (25.4%) patients were smokers while 44 patients (74.6%) were non-smokers. Tumors predominantly occurred in the trachea (28/59,47.5%), the left main bronchus (7/59,11.9%) and the right bronchus (5/59,8.5%). Grossly, the tumors were well circumscribed, greyish-white nodules. Microscopically the tumor cells were small and uniform, and arranged in tubular, cribriform, and solid patterns. Immunohistochemistry showed that the tumor cells were positive for CK7, S-100 protein, Sox-10, CD117 and p63. TTF1 was only positive in 2 cases and Ki-67 index ranged from 3% to 40%. Eighteen cases (30.5%) were gradeⅠ, 26 cases (40.1%) grade Ⅱ, and 15 cases (25.4%) grade Ⅲ. Overall, 39 cases (66.1%), 7 cases (11.9%), 10 cases (16.9%), and 3 cases (5.1%) were at stages Ⅰ, Ⅱ, Ⅲ, and Ⅳ, respectively. Twenty-three patients (39.0%) received surgical therapy, 3 patients (5.1%) surgery combined with radiotherapy, 9 patients (15.2%) surgery combined with chemotherapy, and 24 cases (40.7%) chemotherapy only. No mutation of EGFR, KRAS and BRAF was detected in all 15 tested cases. The overall survival rate at the first, third and fifth years was 94.9%, 86.4% and 84.7%, respectively. Prognostic analysis showed that patient's age and tumor size were statistically associated with the survival (P<0.05). Conclusions: Majority of the patients with primary pulmonary adenoid cystic carcinoma are at an early clinical stage with a favorable prognosis. The size of the tumor and the age of the patients are independent prognostic indicators.

[Expression of BRD4 in squamous cell carcinoma and its effects on cell proliferation and invasion ability]

Objective: To investigate the expression of BRD4 in squamous cell carcinoma (SCC) tissues and cells, and the effects of its expression on cell proliferation and invasion ability. Methods: Immunohistochemistry was used to detect BRD4 protein expression in SCC tissues and paired normal esophageal squamous epithelial tissues. The expression of BRD4 protein was detected in different SCC cell lines and normal esophageal squamous epithelial cells by Western blot. BRD4 siRNA and control siRNA were used to transfect SCC Eca109 cells, and experiments were divided into three groups: untreated group, control siRNA group and BRD4 siRNA group. Western blot was employed to investigate the expression of BRD4 protein in the three groups of SCC Eca109 cells. CCK-8 kit was utilized to detect cell proliferation ability, and Transwell chamber was used to examine cell invasion ability. Finally, Western blot was used to detect the expression of MMP2 and MMP9 proteins. Results: The positive rate of BRD4 protein expression in SCC tissues was significantly higher than that of normal squamous epithelial tissues. The expression of BRD4 protein in 4 SCC cell lines was higher than that in normal esophageal cell Het-1A. BRD4 siRNA obviously downregulated the expression of BRD4 protein in Eca109 cells, and its downregulation contributed to the suppression of cell proliferation and invasion ability in Eca109 cells (all P<0.05), coupled with the decreases of MMP2 and MMP9 proteins. Conclusion: BRD4 may be closely associated with the proliferation and invasion of SCC, and it thus may be a potential therapeutic target for SCC.

Molecular architecture of photoreceptor phosphodiesterase elucidated by chemical cross-linking and integrative modeling

Photoreceptor phosphodiesterase (PDE6) is the central effector enzyme in visual excitation pathway in rod and cone photoreceptors. Its tight regulation is essential for the speed, sensitivity, recovery and adaptation of visual detection. Although major steps in the PDE6 activation/deactivation pathway have been identified, mechanistic understanding of PDE6 regulation is limited by the lack of knowledge about the molecular organization of the PDE6 holoenzyme (αβγγ). Here, we characterize the PDE6 holoenzyme by integrative structural determination of the PDE6 catalytic dimer (αβ), based primarily on chemical cross-linking and mass spectrometric analysis. Our models built from high-density cross-linking data elucidate a parallel organization of the two catalytic subunits, with juxtaposed α-helical segments within the tandem regulatory GAF domains to provide multiple sites for dimerization. The two catalytic domains exist in an open configuration when compared to the structure of PDE2 in the apo state. Detailed structural elements for differential binding of the γ-subunit to the GAFa domains of the α- and β-subunits are revealed, providing insight into the regulation of the PDE6 activation/deactivation cycle.

Functional mapping of interacting regions of the photoreceptor phosphodiesterase (PDE6) γ-subunit with PDE6 catalytic dimer, transducin, and regulator of G-protein signaling9-1 (RGS9-1)

The cGMP phosphodiesterase (PDE6) involved in visual transduction in photoreceptor cells contains two inhibitory γ-subunits (Pγ) which bind to the catalytic core (Pαβ) to inhibit catalysis and stimulate cGMP binding to the GAF domains of Pαβ. During visual excitation, interaction of activated transducin with Pγ relieves inhibition. Pγ also participates in a complex with RGS9-1 and other proteins to accelerate the GTPase activity of activated transducin. We studied the structural determinants for these important functions of Pγ. First, we identified two important sites in the middle region of Pγ (amino acids 27-38 and 52-54) that significantly stabilize the overall binding affinity of Pγ with Pαβ. The ability of Pγ to stimulate noncatalytic cGMP binding to the GAF domains of PDE6 has been localized to amino acids 27-30 of Pγ. Transducin activation of PDE6 catalysis critically depends on the presence of Ile54 in the glycine-rich region of Pγ in order to relieve inhibition of catalysis. The central glycine-rich region of Pγ is also required for transducin to increase cGMP exchange at the GAF domains. Finally, Thr-65 and/or Val-66 of Pγ are critical residues for Pγ to stimulate GTPase activity of transducin in a complex with RGS9-1. We propose that the glycine-rich region of Pγ is a primary docking site for PDE6-interacting proteins involved in the activation/inactivation pathways of visual transduction. This functional mapping of Pγ with its binding partners demonstrates the remarkable versatility of this multifunctional protein and its central role in regulating the activation and lifetime of visual transduction.

Preliminary X-ray crystallographic analysis of SMU.2055 protein from the caries pathogen Streptococcus mutans

The SMU.2055 gene from the major caries pathogen Streptococcus mutans is annotated as a putative acetyltransferase with 163 amino-acid residues. In order to identify its function via structural studies, the SMU.2055 gene was cloned into the expression vector pET28a. Native and SeMet-labelled SMU.2055 proteins with a His(6) tag at the N-terminus were expressed at a high level in Escherichia coli strain BL21 (DE3) and purified to homogeneity by Ni(2+)-chelating affinity chromatography. Diffraction-quality crystals of SeMet-labelled SMU.2055 were obtained using the sitting-drop vapour-diffusion method and diffracted to a resolution of 2.5 A on beamline BL17A at the Photon Factory, Tsukuba, Japan. The crystals belong to the orthorhombic space group C222(1), with unit-cell parameters a = 92.0, b = 95.0, c = 192.2 A. The asymmetric unit contained four molecules, with a solvent content of 57.1%.

Cloning and expression analysis of phytoene desaturase and ζ-carotene desaturase genes in Carica papaya

The fruit flesh color of papaya is an important nutritional quality trait and is due to the accumulation of carotenoid. To elucidate the carotenoid biosynthesis pathway in Carica papaya, the phytoene desaturase (PDS) and the ζ-carotene desaturase (ZDS) genes were isolated from papaya (named CpPDS and CpZDS) using the rapid amplification of cDNA ends (RACE) approach, and their expression levels were investigated in red- and yellow-fleshed papaya varieties. CpPDS contains a 1749 bp open reading frame coding for 583 amino acids, while CpZDS contains a 1716 bp open reading frame coding for 572 amino acids. The deduced CpPDS and CpZDS proteins contain a conserved dinucleotide-binding site at the N-terminus and a carotenoid-binding domain at the C-terminus. Papaya genome sequence analysis revealed that CpPDS and CpZDS are single copy; the CpPDS was mapped to papaya chromosome LG6, and the CpZDS was mapped to chromosome LG3. Quantitative PCR showed that both CpPDS and CpZDS were expressed in all tissues examined with the highest expression in maturing fruits, and that the expression of CpPDS and CpZDS were higher in red-fleshed fruits than in yellow-fleshed fruits. These results indicated that the differential accumulation of carotenoids in red- and yellow-fleshed papaya varieties might be partly explained by the transcriptional level of CpPDS and CpZDS.

Protein preparation, crystallization and preliminary X-ray crystallographic analysis of N-acetylglutamate kinase from Streptococcus mutans

The N-acetylglutamate kinase from Streptococcus mutans was expressed in Escherichia coli in soluble form and purified to homogeneity. Crystals suitable for X-ray diffraction were obtained by hanging-drop vapor diffusion method and diffracted to 2.06 A. The crystal belonged to space group P2(1)2(1)2, with unit cell parameters a = 57.19 A, b =94.76 A, c =47.58 A. The gel filtration and initial phasing results showed that the enzyme exists as a monomer, which is different from previously reported N-acetylglutamate kinases.

Protein preparation, crystallization and preliminary X-ray crystallographic analysis of SMU.961 protein from the caries pathogen Streptococcus mutans

The smu.961 gene encodes a putative protein of 183 residues in Streptococcus mutans, a major pathogen in human dental caries. The gene was cloned into expression vector pET28a and expressed in a substantial quantity in Escherichia coli strain BL21 (DE3) with a His tag at its N-terminus. The recombinant protein SMU.961 was purified to homogeneity in a two-step procedure consisting of Ni2+-chelating and size-exclusion chromatography. Crystals suitable for X-ray diffraction were obtained by the hanging-drop vapour-diffusion method and diffracted to 2.9 A resolution at beamline I911-3, MAX-II-lab, Sweden. The crystal belonged to space group C2, with unit-cell parameters a = 98.62, b = 73.73, c = 184.73 A, beta = 98.82 degrees.

[Antigen analysis of Trichomonas vaginalis trophozoite by SDS-PAGE and two-dimensional gel electrophoresis]

OBJECTIVE

To analyze soluble antigens of Trichomonas vaginalis.

METHODS

Soluble antigens of the parasite from a patient suffering from trichomonad vaginitis were analyzed by SDS-PAGE, immunoblotting and two-dimensional gel electrophoresis.

RESULTS

A total of 26 distinct protein bands were demonstrated by using 10% resolution gel. Nine of them were main bands, eight with MWs 15-62 kDa, one with MW 97 kDa. By immunoblotting the specific anti-T. vaginalis antibodies raised in rabbit recognized 24 protein bands with 8 main bands in them. Two-dimensional gel electrophoresis revealed up to 43 individual trichomonad polypeptide spots, among which, 9 were main ones. The pI and MWs of these spots were 3.65-5.84 and 27-->100 kDa respectively.

CONCLUSION

Eight protein bands out of 26 soluble antigen bands of the parasite showed high immunogenicity. There were 9 main polypeptide spots in 43 polypeptide spots of the parasite.

[Effect of anti-mosquito-midgut antibodies on the development of oocysts of Plasmodium yoelii in Anopheles stephensi]

OBJECTIVE

To study the effect of anti-mosquito-midgut antibodies on the development of P. yoelii in A. stephensi.

METHODS

Ookinetes and oocysts in midgut and sporozoites in the salivary glands of mosquitoes were examined respectively at 14 h and 9 d and 12 d after the mosquitoes ingested infected blood containing anti-midgut antibodies by membrane feeders. The effect of anti-midgut antibody level and repeated feedings on the development of the oocysts in the mosquitoes was also observed.

RESULTS

The anti-midgut antibodies reduced evidently not only the infection rates of the oocysts and the number of the sporozoites in salivary gland but also infection degree of ookinetes and the index of oocysts in the mosquitoes compared with control group (P < 0.05). The higher the antibody level, the more the times for mosquitoes digested antibodies, and the fewer the number of oocysts.

CONCLUSION

The anti-mosquito-mindgut antibodies inhibited ookinetes and oocysts of P. yoelii in A. stephensi, with oocysts in particular.

Marrow cytokine transcripts and the secondary hematologic disorders

A comparison was made of the cytokine transcripts in normal, monoclonal, MDS, and AML marrow aspirates. While both normal and monoclonal marrow aspirates contain transcripts for SCF, few MDS or AML marrow aspirates contain these transcripts. Similarly, IL1ra transcripts are found with reduced frequency in MDS and AML marrow aspirates. The fall in SCF transcripts between monoclonal and MDS marrow aspirates parallels the appearance of apoptosis and the reduced in vitro proliferative ability which are characteristics of MDS marrow aspirate cells. The frequent IL1beta production by MDS and AML marrow aspirate cells, with few marrow aspirates producing IL1ra transcripts, suggests that unbalanced IL1beta effects may contribute to the proliferative advantage of MDS and AML cells over their normal counterparts.

The ABL/BCR fusion gene on chromosome 9 in Ph-negative chronic myelogenous leukemia: a case for vigilance in fluorescence in situ hybridization interpretation

We report cytogenetic, fluorescence in situ hybridization (FISH), and molecular analysis in a case of Ph-negative chronic myelogenous leukemia patient with ABL/BCR fusion gene on chromosome 9 and a disparate FISH signal pattern using two commercially available bcr/abl probes (Vysis, Inc. and Oncor, Inc.). Cytogenetic analysis revealed a 46,XX normal female karyotype. FISH studies using Vysis LSI bcr/abl probe in interphase cells demonstrated a BCR/ABL fusion pattern, similar to that of m-BCR/ABL fusion found in acute lymphoblastic leukemia. However, examination of metaphases revealed the ABL/BCR fusion signal on one of the chromosomes 9, an ABL signal on the other chromosome 9, and two BCR signals of different sizes on each of the chromosomes 22. Subsequently, a FISH study with the Oncor major (M)-bcr/abl translocation probe confirmed the ABL/BCR fusion signal on chromosome 9 in addition to an ABL signal and a BCR signal located on chromosomes 9 and 22, respectively. Molecular studies (RT-PCR) revealed a rearrangement of the M-BCR region and expression of a chimeric bcr/abl mRNA of b3a2 configuration. This case suggests that it is imperative to have a full understanding of both the capabilities and the limitations of bcr/abl translocation probes and that FISH interphase signals should be confirmed on metaphase spreads for accurate diagnosis.

Cytokine gene activity in AML cells in vivo in patients

The proliferation of acute myelogenous leukemia cells is dependent upon cytokine stimulation. Additionally, there is a body of literature which reports that leukemia cells produce GMCSF, IL6, and other cytokines. The study reported here, using an rt-multiplex polymerase method, determined the presence or absence of transcripts in freshly obtained AML cells for the following cytokine or cytokine-related genes: IL 1beta, IL1ra, TNF alpha, GMCSF, IL6, flt 3, and hSCF. This demonstrated that leukemia cell populations usually contain transcripts for IL1beta, TNF alpha, flt 3 and flt 3 ligand in vivo and that transcripts for the other cytokines only appear after the leukemia cells are processed in vitro. The presence of TNF alpha transcripts appears to be associated with resistance to remission induction therapy. Furthermore, the transcript profile of the leukemia cells can change during remission induction therapy. The data also demonstrate the assessment of cytokine production by leukemia cells after in vitro manipulation should not be extrapolated to the in vivo situation.

Two in situ labeling techniques reveal different patterns of DNA fragmentation during spontaneous apoptosis in vivo and induced apoptosis in vitro

BACKGROUND

Two new enzymatic reactions were described recently to detect apoptotic cell death in situ viz in situ end labeling (ISEL) and terminal deoxynucleotidyl transferase mediated UTP nick end labeling (TUNEL) of fragmented DNA. A comparative study was conducted to detect in vivo and in vitro apoptotic death using these two techniques. Experimental design; Spontaneous apoptous cell death was detected in plastic embedded tumor biopsies from patients with non-Hodgkin's lymphoma (NHL), head and neck squamous cell carcinomas (HNSCC), and breast cancer using these two in situ methods. Uninvolved normal tissues adjacent to breast tumors and a lymph node metastasis of breast tumor were also studied. Furthermore, apoptotic death induced by different doses of etoposide (VP16) was also studied in HL60 cells by in situ methods and by agarose gel electrophoresis.

RESULTS

Interestingly, whereas NH1 and HNSCC biopsies showed comparable levels of detectability with the two techniques, the breast tissues be it neoplastic, normal or metastatic, revealed apoptosis detectable only by TUNEL and not by ISEL. Similarly in HL60 cells, the percentage of apoptotic cells or apoptotic index (AI) determined by TUNEL was significantly higher than that determined by ISEL. A double labelling of these HL60 cells for ISEL and TUNEL also revealed a higher proportion of cells labeled positively for TUNEL as compared to those labeled for ISEL. Agarose gel electrophoresis revealed characteristic DNA laddering only at 35 microM dose of VP 16. No smearing of DNA was found in any group ruling out the necrotic death. In vivo, in one HNSCC specimen apoptosis and necrosis could be differentiated by the difference in staining intensity. Both methods stained necrotic chromatin fragments very lightly. The DNA fragments generated during apoptosis could be of unique lengths (ie 180-200 bp or multiples) but have differently staggered ends. These fragments may be 3' recessed, 5' recessed or blunt ended. While TUNEL can label all three types, ISEL labels only those with 3' recessed ends.

CONCLUSIONS

Thus our data show that the DNA fragments formed during spontaneous apoptosis in breast tissues and preferentially during VP16 induced apoptosis in HL60 cells are either 5' recessed or blunt ended, being distinctly different from 3' recessed fragments seen in NHL and HNSCC or with a lesser frequency in VP 16 treated HL60 cells. Specific fragmentation patterns could be a result of activation of different endonucleases which as indicated by our data could be tissue specific and may be differentially activated by different chemotherapeutic agents. Therefore, screening for the presence of specific endonucleases in different tissues and for agents specifically activating them would have major clinical implications.

Apoptosis in bone marrow biopsy samples involving stromal and hematopoietic cells in 50 patients with myelodysplastic syndromes

Cell-cycle kinetics were measured in situ after infusions of iododeoxyuridine and/or bormodeoxyuridine in 50 patients with myelodysplastic syndromes (MDS) and the median labeling index in bone marrow (BM) biopsy samples was 28.6%. Unfortunately, 26 of 50 patients showed that > or = 75% of hematopoietic cells of all three lineages were undergoing programmed cell death (PCD) in their biopsy samples as shown by the in situ end labeling (ISEL) technique. Ten patients had 1/3 and eight had 2/3 ISEL+ cells. Stromal cells were frequently ISEL+ and often S-phase cells were also found to be simultaneously ISEL+. Nucleosomal DNA fragments as a ladder in agarose gel were present in BM aspirates of four patients who showed high ISEL and were absent in two who had no ISEL staining in biopsy samples, but only when DNA was extracted after a 4-hour in vitro incubation in complete medium. Therefore, laddering data confirmed the ISEL findings that the majority of hematopoietic cells in MDS are in early stages of PCD. We conclude that extensive intramedullary cell death may explain the paradox of pancytopenia despite hypercellular marrows in MDS patients. Investigating approaches that protect against PCD in some MDS subsets would be of interest.

Recombinant human G-CSF and retinoic acid in synergistically inducing granulocyte differentiation of human promyelocytic leukemic cells

The effects of recombinant human G-CSF (rhG-CSF) and retinoic acid (RA) were studied on the proliferation and differentiation of HL-60 cells and human acute myeloid leukemic cells. Synergistic effect on granulocyte differentiation was observed when HL-60 cells and primary acute promyelocytic leukemic cells were cocultured with RA plus rhG-CSF. rhG-CSF combined with RA increased more significantly the percentage of mature cells than RA alone and greatly increased NBT reduction activity (P < 0.001). These results suggested that proliferated effect of rhG-CSF on leukemic cells may be important for inducing differentiation of myeloid leukemic cells. But this effect might expose the patients to the risk of acute myeloblastic leukemia if G-CSF was used alone. However, RA could not only rule out the latter situation but retain former merit as well. The authors suggest that the combined use of G-CSF with RA is probably a new approach to the treatment of leukemia.

Effects of rGM-CSF on leukemia cell proliferation and on the incorporation of cytosine arabinoside into DNA

In vitro studies of the effects of recombinant granulocyte macrophage-colony stimulating factor (rGM-CSF) on freshly obtained human leukemia cells were conducted to determine if there is a relationship between the effects of this growth factor on the proliferative characteristics of leukemia cells and on their incorporation of cytosine arabinoside (araC) into DNA. While rGM-CSF was found to be able to stimulate both leukemia cell proliferation and araC incorporation, for individual leukemia specimens there was no consistent relationship among these effects. In some specimens proliferation was stimulated without an increase in araC incorporation. The reverse was also observed. These studies demonstrate the difficulty in identifying assays capable of predicting the clinical effects of growth factors on leukemia cells in patients since the effect in vitro vary with the assay.

Second meiotic division of Plasmodium vivax

During the formation of sporozoites, the nuclei formed after mitotic division in sporoblast enter sporozoite buds. The spindle appears in the nucleus of the sporozoite bud, while its nuclear membrane disappears. The spindle is an evidence of the second meiosis of the life cycle of plasmodium.

Studies of the proliferation and differentiation of immature myeloid cells in vitro: 4: Preculture proto-oncogene expression and the behaviour of myeloid leukemia cells in vitro

Studies were conducted to determine the relationship between the pretherapy characteristics of leukemia cells and their behaviour during culture in vitro. Leukemia cells which proliferated well in vitro also proliferated well in vivo. Cells which manifested myeloid or monocytic differentiation in vivo tended to manifest differentiation along these lines in vitro. Cells which manifested high levels of expression of c-fms, c-fes, or triose phosphate isomerase prior to culture were likely to differentiate in vitro, with high levels of c-fes expression being related to myeloid maturation. These observations suggest that differentiation at the molecular level prior to culture is a requisite for leukemia cell differentiation in vitro. The same may be true for differentiation in vivo under the influence of exogenously administered agents such as cytotoxic chemotherapy or recombinant growth factors.

The effects of cytosine arabinoside and GM-CSF in leukemic cells in vitro

An in vitro pilot study was conducted of the possible utility of combining low doses of cytosine arabinoside (araC) and GM-CSF to stimulate leukemic cell differentiation. Cytosine arabinoside induced macrophage differentiation in some cultures but only when the drug produced substantial cytostatic effects. GM-CSF, when present alone, failed to induce leukemic cell differentiation. When GM-CSF and araC were simultaneously present the level of both araC associated cytotoxicity and araC associated differentiation were reduced in 3 studies. In only a single study was there evidence suggesting that GM-CSF increased araC-associated differentiation.

Studies of the proliferation and differentiation of immature myeloid cells in vitro. I. Chronic myelogenous leukemia

Immature cells prepared from chronic myelogenous leukemic patients in the chronic or blastic phase of their disease were placed into suspension culture in vitro and studied over a 2-week period. Regardless of the status of the disease, the immature cells proliferated and maintained good viability. In contrast, evolution of the disease toward blastic crisis was associated with a progressive loss in the ability of the immature cells to differentiate. Cell proliferation and differentiation were independent of added growth factors.

Studies of the proliferation and differentiation of immature myeloid cells in vitro. II. Acute myelogenous leukemia

Immature myeloid cells prepared from patients with AML were placed into suspension culture and studied over a 2-week period. Cell numbers usually fell and viability was not well maintained. Some degree of differentiation was observed in most cultures. Considering these observations, together with those derived from parallel studies of immature CML cells, the data suggest that AML cells are more dependent than CML cells on environmental conditions for the maintenance of cell viability and proliferation. This is especially the case for AML cells obtained at the time of initial diagnosis. On the other hand, AML cells and myeloid blastic crisis CML cells are similar with respect to their apparent greater ability to differentiate in vitro than in vivo. The addition of recombinant hemopoietins to the suspension cultures of AML cells is associated with either increased proliferation or differentiation but not both. The cells of different patients respond differently to the different hemopoietins and the different hemopoietins produce different affects in cultures of cells obtained from the same patient.

Proto-oncogene expression during early myeloid differentiation of normal peripheral blood progenitor cells

Peripheral blood mononuclear cells cultured in liquid medium with fetal calf serum undergo differentiation to myeloblasts (7 days) and then mature granulocytes (14-21 days). This culture system was used to study proto-oncogene expression during pre-myeloblast myeloid differentiation. c-myc mRNA was present in the peripheral blood mononuclear cells placed into culture, fell during the first 2-4 days of culture and then rose between days 2-4 and day 7 of culture, prior to and coincident with the appearance of myeloblasts. Histone H3 mRNA was absent or present at very low levels at initiation of cultures, and then rose throughout the first 7 days of culture. c-fms mRNA was absent at initiation of cultures, and appeared on days 2-5 of culture, prior to the appearance of myeloblasts. c-fos mRNA was not detected during differentiation of peripheral blood mononuclear cells to myeloblasts. Elucidation of patterns of proto-oncogene expression during normal myeloid differentiation is a prerequisite for interpretation of proto-oncogene expression in myeloid leukemia cells.

Enhanced expression of the granulocyte-macrophage colony stimulating factor gene in acute myelocytic leukemia cells following in vitro blast cell enrichment

Expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene in acute myelocytic leukemia (AML) was assayed by Northern blot analysis. GM-CSF messenger RNA (mRNA) was detected in the freshly obtained mononuclear cells of only one of 48 cases of AML, in contrast with recent reports that GM-CSF mRNA might be detected in half of the cases of AML when RNA is prepared from T-cell- and monocyte-depleted leukemic cells. We did find, however, that expression of the GM-CSF gene was detectable in five of ten cases after in vitro T-cell and monocyte depletion steps. Additional studies suggest that expression of GM-CSF in the bone marrow of the one positive case, rather than being autonomous, was under exogenous control, possibly by a paracrine factor secreted by marrow stromal cells. These studies emphasize the potential for altering in vivo patterns of gene expression by in vitro cell manipulation.

Sustained viability of acute myelogenous leukemia cells in liquid suspension culture correlates with occurrence of differentiation

To examine the relationship between viability of acute myelogenous leukemia (AML) blasts in liquid suspension culture and the occurrence of myeloid maturation in culture, total and differential cell counts and viability as determined by trypan blue dye exclusion were followed over 21 days of culture. A significant positive correlation was found between viability of cells on day 21 of culture and percentage of mature cells present. These data suggest that myeloid maturation may be a mechanism by which AML cells maintain viability in an adverse environment.