Application of modern computer technology in classical genetics lab course--Development of a mobile, lightweight and high-precision batch identification system for genetic traits of Drosophila

Drosophila is a crucial biological experimental teaching material extensively utilized in experimental teaching. In this experimental teaching, each student typically needs to manually identify hundreds of fruit flies and record multiple of each fly. This task involves substantial workload, and the classification standards can be inconsistent. To address this issue, we introduce a deep convolutional neural network that classifies the traits of every fruit fly, using a two-stage consisting of an object detector and a trait classifier. We propose a keypoint-assisted classification model with tailored training session for the trait classification task and significantly enhanced the model interpretability. Additionally, we've enhanced the RandAugment method to better fit the features of our task. The model is trained with progressive learning and adaptive regularization under limited computational resources. The final classification model, which utilizes MobileNetV3 as backbone, achieves an accuracy of 97.5%, 97.5% and 98% for the eyes, wings, gender tasks, respectively. After optimization, the model is highly lightweight, classifying 600 fruit fly traits from raw images in 10 seconds and having a size less than 5 MB. It can be easily deployed on any android device. The development of this system is conducive to promoting the experimental teaching, such as verifying genetic laws with Drosophila as the research object. It can also be used for scientific research involving a large number of Drosophila classifications, statistics and analyses.

Integrative genomic and transcriptomic profiling reveals distinct molecular subsets in adult mixed phenotype acute leukemia

Mixed phenotype acute leukemia (MPAL) is a subtype of leukemia in which lymphoid and myeloid markers are co-expressed. Knowledge regarding the genetic features of MPAL is lacking due to its rarity and heterogeneity. Here, we applied an integrated genomic and transcriptomic approach to explore the molecular characteristics of 176 adult patients with MPAL, including 86 patients with T-lymphoid/myeloid MPAL (T/My MPAL-NOS), 42 with Ph+ MPAL, 36 with B-lymphoid/myeloid MPAL (B/My MPAL-NOS), 4 with t(v;11q23), and 8 with MPAL, NOS, rare types. Genetically, T/My MPAL-NOS was similar to B/T MPAL-NOS but differed from Ph+ MPAL and B/My MPAL-NOS. T/My MPAL-NOS exhibited higher CEBPA, DNMT3A, and NOTCH1 mutations. Ph+ MPAL demonstrated higher RUNX1 mutations. B/T MPAL-NOS showed higher NOTCH1 mutations. By integrating next-generation sequencing and RNA sequencing data of 89 MPAL patients, we defined eight molecular subgroups (G1-G8) with distinct mutational and gene expression characteristics. G1 was associated with CEBPA mutations, G2 and G3 with NOTCH1 mutations, G4 with BCL11B rearrangement and FLT3 mutations, G5 and G8 with BCR::ABL1 fusion, G6 with KMT2A rearrangement/KMT2A rearrangement-like features, and G7 with ZNF384 rearrangement/ZNF384 rearrangement-like characteristics. Subsequently, we analyzed single-cell RNA sequencing data from five patients. Groups G1, G2, G3, and G4 exhibited overexpression of hematopoietic stem cell disease-like and common myeloid progenitor disease-like signatures, G5 and G6 had high expression of granulocyte-monocyte progenitor disease-like and monocyte disease-like signatures, and G7 and G8 had common lymphoid progenitor disease-like signatures. Collectively, our findings indicate that integrative genomic and transcriptomic profiling may facilitate more precise diagnosis and develop better treatment options for MPAL.

Reactivation of γ-globin expression using a minicircle DNA system to treat β-thalassemia

Reactivation of fetal hemoglobin by editing the B-cell lymphoma/leukemia 11A (BCL11A) erythroid enhancer is an effective gene therapy for β-thalassemia. Using the CRISPR/Cas9 system, fetal γ-globin expression can be robustly reactivated to mitigate the clinical course of β-thalassemia. In our study, we found that the transfection efficiencies of CD34+ hematopoietic stem/progenitor cells (HSPCs) were significantly and negatively correlated with the length of plasmids and greatly affected by the linearization of plasmids. Furthermore, the transgene expression of minicircles (MC) without plasmid backbone sequences was better both in vitro and in vivo compared with conventional plasmids. Thus, MC DNA was used to deliver the cassette of Staphylococcus aureus Cas9 (SaCas9) into HSPCs, and a single-guide RNA targeting the erythroid enhancer region of BCL11A was selected. After electroporation with MC DNA, an evident efficiency of gene editing and reactivation of γ-globin expression in erythroblasts derived from unsorted HSPCs was acquired. No significant off-target effects were found by deep sequencing. Furthermore, fragments derived from lentiviral vectors, but not MC DNA, were highly enriched in promoter, exon, intron, distal-intergenic, and cancer-associated genes, indicating that MC DNA provided a relatively safe and efficient vector for delivering transgenes. The developed MC DNA vector provided a potential approach for the delivery of SaCas9 cassette and the reactivation of γ-globin expression for ameliorating syndromes of β-thalassemia.

Long noncoding RNA HBBP1 enhances γ-globin expression through the ETS transcription factor ELK1

β-Thalassemia is an autosomal recessive genetic disease caused by defects in the production of adult hemoglobin (HbA, α₂β₂), which leads to an imbalance between α- and non-α-globin chains. Reactivation of γ-globin expression is an effective strategy to treat β-thalassemia patients. Previously, it was demonstrated that hemoglobin subunit beta pseudogene 1 (HBBP1) is associated with elevated fetal hemoglobin (HbF, α₂γ₂) in β-thalassemia patients. However, the mechanism underlying HBBP1-mediated HbF production is unknown. In this study, using bioinformatics analysis, we found that HBBP1 is involved in γ-globin production, and then preliminarily confirmed this finding in K562 cells. When HBBP1 was overexpressed, γ-globin expression was increased at the transcript and protein levels in HUDEP-2 cells. Next, we found that ETS transcription factor ELK1 (ELK1) binds to the HBBP1 proximal promoter and significantly promotes its activity. Moreover, the synthesis of γ-globin was enhanced when ELK1 was overexpressed in HUDEP-2 cells. Surprisingly, ELK1 also directly bound to and activated the γ-globin proximal promoter. Furthermore, we found that HBBP1 and ELK1 can interact with each other in HUDEP-2 cells. Collectively, these findings suggest that HBBP1 can induce γ-globin by enhancing ELK1 expression, providing some clues for γ-globin reactivation in β-thalassemia.

Phylogenetic analysis of the Y-chromosome haplogroup C2b-F1067, a dominant paternal lineage in Eastern Eurasia

Human Y-chromosome haplogroup C2b-F1067 is one of the dominant paternal lineages of populations in Eastern Eurasia. In order to explore the origin, diversification, and expansion of this haplogroup, we generated 206 new Y-chromosome sequences from C2b-F1067 males and coanalyzed 220 Y-chromosome sequences of this haplogroup. BEAST software was used to reconstruct a revised phylogenetic tree of haplogroup C2b-F1067 with age estimates. The revised phylogeny of C2b-F1067 included 155 sublineages, 1986 non-private variants, and >6000 private variants. The age estimation suggested that the initial splitting of C2b-F1067 happened at about 32.8 thousand years ago (kya) and the major sublineages of this haplgroup experienced continuous expansion in the most recent 10,000 years. We identified numerous sublineages that were nearly specific for Korean, Mongolian, Chinese, and other ethnic minorities in China. In particular, we evaluated the candidate-specific lineage for the Dayan Khan family and the Confucius family, the descendants of the ruling family of the Chinese Shang dynasty. These findings suggest that ancient populations with varied C2b-F1067 sublineages played an important role during the formation of most modern populations in Eastern Eurasia, and thus eventually became the founding paternal lineages of these populations.

Impact of palbociclib plus letrozole on patient-reported health-related quality of life: results from the PALOMA-2 trial

Background

Patient-reported outcomes are integral in benefit-risk assessments of new treatment regimens. The PALOMA-2 study provides the largest body of evidence for patient-reported health-related quality of life (QOL) for patients with metastatic breast cancer (MBC) receiving first-line endocrine-based therapy (palbociclib plus letrozole and letrozole alone).

Patients and methods

Treatment-naïve postmenopausal women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) MBC were randomized 2 : 1 to palbociclib plus letrozole (n = 444) or placebo plus letrozole (n = 222). Patient-reported outcomes were assessed at baseline, day 1 of cycles 2 and 3, and day 1 of every other cycle from cycle 5 using the Functional Assessment of Cancer Therapy (FACT)-Breast and EuroQOL 5 dimensions (EQ-5D) questionnaires.

Results

As of 26 February 2016, the median duration of follow-up was 23 months. Baseline scores were comparable between the two treatment arms. No significant between-arm differences were observed in change from baseline in FACT-Breast Total, FACT-General Total, or EQ-5D scores. Significantly greater improvement in pain scores was observed in the palbociclib plus letrozole arm (-0.256 versus -0.098; P = 0.0183). In both arms, deterioration of FACT-Breast Total score was significantly delayed in patients without progression versus those with progression and patients with partial or complete response versus those without. No significant difference was observed in FACT-Breast and EQ-5D index scores in patients with and without neutropenia.

Conclusions

Overall, women with MBC receiving first-line endocrine therapy have a good QOL. The addition of palbociclib to letrozole maintains health-related QOL and improves pain scores in treatment-naïve postmenopausal patients with ER+/HER2- MBC compared with letrozole alone. Significantly greater delay in deterioration of health-related QOL was observed in patients without progression versus those who progressed and in patients with an objective response versus non-responders. ClinicalTrials.gov: NCT01740427 (https://clinicaltrials.gov/ct2/show/NCT01740427).

Clinical considerations of the role of palbociclib in the management of advanced breast cancer patients with and without visceral metastases

Background

This report assesses the efficacy and safety of palbociclib plus endocrine therapy (ET) in women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (ABC) with or without visceral metastases.

Patients and methods

Pre- and postmenopausal women with disease progression following prior ET (PALOMA-3; N = 521) and postmenopausal women untreated for ABC (PALOMA-2; N = 666) were randomized 2 : 1 to ET (fulvestrant or letrozole, respectively) plus palbociclib or placebo. Progression-free survival (PFS), safety, and patient-reported quality of life (QoL) were evaluated by prior treatment and visceral involvement.

Results

Visceral metastases incidence was higher in patients with prior resistance to ET (58.3%, PALOMA-3) than in patients naive to ET in the ABC setting (48.6%, PALOMA-2). In patients with prior resistance to ET and visceral metastases, median PFS (mPFS) was 9.2 months with palbociclib plus fulvestrant versus 3.4 months with placebo plus fulvestrant [hazard ratio (HR), 0.47; 95% confidence interval (CI), 0.35–0.61], and objective response rate (ORR) was 28.0% versus 6.7%, respectively. In patients with nonvisceral metastases, mPFS was 16.6 versus 7.3 months, HR 0.53; 95% CI 0.36–0.77. In patients with visceral disease and naive to ET in the advanced disease setting, mPFS was 19.3 months with palbociclib plus letrozole versus 12.9 months with placebo plus letrozole (HR 0.63; 95% CI 0.47–0.85); ORR was 55.1% versus 40.0%; in patients with nonvisceral disease, mPFS was not reached with palbociclib plus letrozole versus 16.8 months with placebo plus letrozole (HR 0.50; 95% CI 0.36–0.70). In patients with prior resistance to ET with visceral metastases, palbociclib plus fulvestrant significantly delayed deterioration of QoL versus placebo plus fulvestrant, whereas patient-reported QoL was maintained with palbociclib plus letrozole in patients naive to endocrine-based therapy for ABC.

Conclusions

Palbociclib plus ET prolonged mPFS in patients with visceral metastases, increased ORRs, and in patients previously treated for ABC, delayed QoL deterioration, presenting a standard treatment option among patients with visceral metastases amenable to endocrine-based therapy.

Clinical trial registration

NCT01942135, NCT01740427

Palbociclib plus letrozole as first-line therapy in estrogen receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer with extended follow-up

PURPOSE

In the initial PALOMA-2 (NCT01740427) analysis with median follow-up of 23 months, palbociclib plus letrozole significantly prolonged progression-free survival (PFS) in women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) [hazard ratio (HR) 0.58; P < 0.001]. Herein, we report results overall and by subgroups with extended follow-up.

METHODS

In this double-blind, phase 3 study, post-menopausal women with ER+/HER2- ABC who had not received prior systemic therapy for their advanced disease were randomized 2:1 to palbociclib-letrozole or placebo-letrozole. Endpoints include investigator-assessed PFS (primary), safety, and patient-reported outcomes (PROs).

RESULTS

After a median follow-up of approximately 38 months, median PFS was 27.6 months for palbociclib-letrozole (n = 444) and 14.5 months for placebo-letrozole (n = 222) (HR 0.563; 1-sided P < 0.0001). All subgroups benefited from palbociclib treatment. The improvement of PFS with palbociclib-letrozole was maintained in the next 2 subsequent lines of therapy and delayed the use of chemotherapy (40.4 vs. 29.9 months for palbociclib-letrozole vs. placebo-letrozole). Safety data were consistent with the known profile. Patients' quality of life was maintained.

CONCLUSIONS

With approximately 15 months of additional follow-up, palbociclib plus letrozole continued to demonstrate improved PFS compared with placebo plus letrozole in the overall population and across all patient subgroups, while the safety profile remained favorable and quality of life was maintained. These data confirm that palbociclib-letrozole should be considered the standard of care for first-line therapy in patients with ER+/HER2- ABC, including those with low disease burden or long disease-free interval. Sponsored by Pfizer; ClinicalTrials.gov: NCT01740427.

Detection of the clarithromycin resistance of Helicobacter pylori in gastric mucosa by the amplification refractory mutation system combined with quantitative real-time PCR

The goal of this study was to evaluate the feasibility of detecting Helicobacter pylori clarithromycin resistance in gastric mucosa using the amplification refractory mutation system combined with quantitative real-time PCR (ARMS-PCR). Gastric mucosal specimens (150) were collected from patients who were unsuccessfully treated for H. pylori eradication. Each specimen was divided into 2 samples. One sample was used to extract genomic DNA and detect any gene mutations of H. pylori produced by ARMS- PCR. Sequencing was used to assess the accuracy of this method. The other sample was used to culture H. pylori. The E-test minimum inhibitory concentration (MIC) was used to assess clarithromycin resistance. The results were compared with a paired chi-square test to validate the coincidence rate among the 3 methods. The coincidence rate between the sequencing and ARMS-PCR results was 98.7%, thus verifying the accuracy of ARMS-PCR. E-tests detected 144 clarithromycin resistance cases, including 45 sensitivity cases; the resistance rate was 70%. The coincidence rate between the results of the E-test and ARMS-PCR was 97.1%, and no significant difference between the 2 methods was observed. ARMS-PCR is a simple and fast method that has high sensitivity and specificity and can be used to detect the clarithromycin resistance of H. pylori in gastric mucosa. ARMS-PCR is expected to be used to study drug resistance mechanisms and use in assays of individual therapies for H. pylori eradication.

Abstract P5-21-03: Palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Efficacy and safety updates with longer follow-up across patient subgroups

BACKGROUND: Endocrine therapy (ET) has been the primary first-line (1L) therapy for ER+ ABC. In the PALOMA-2 study (NCT01740427), PAL (P)+LET (L) significantly prolonged progression-free survival (PFS; HR=0.58, P&lt;.001) after a median 23 mo follow-up (FU) (Finn et al. NEJM 2016). Here we report more mature PFS overall and in subgroups, with (w/) longer FU. The study is ongoing for overall survival FU.

METHODS: Postmenopausal pts w/ ER+/HER2- ABC and no prior systemic therapy in the ABC setting were randomized 2:1 to P (125 mg/d) + L (2.5 mg QD) or placebo (PBO) + L. Key endpoints: investigator-assessed PFS and safety. Median PFS (mPFS) was estimated (intent-to-treat population).

RESULTS: 666 pts (444, P+L; 222, PBO+L) were enrolled. Arms were well balanced: visceral (48%)/nonvisceral (52%) disease and prior ET (56%)/no prior ET (44%). After a median FU of 38 mo w/ P+L and 37 mo w/ PBO+L, mPFS was 27.6 and 14.5 mo, respectively, in the overall population (HR=0.56, P&lt;.0001; Table).

TABLE. mPFS overall and by relevant subgroupsP+LPBO+LP+L vs PBO+LmPFS, mo (95% CI)mPFS, mo (95% CI)HR (95% CI)P* Overall27.6 (22.4–30.3)14.5 (12.3–17.1)0.56 (0.46–0.69)&lt;.0001 Measurable disease23.7 (19.3–27.6)14.5 (12.3–18.5)0.63 (0.50–0.79)&lt;.0001 Nonmeasurable disease36.2 (27.6?NE)16.5 (8.3–19.6)0.39 (0.25–0.60)&lt;.0001 Visceral19.3 (16.4–24.2)12.3 (8.4–16.4)0.62 (0.47–0.81)&lt;.0005 Nonvisceral35.9 (27.7–NE)17.0 (13.8–24.8)0.50 (0.37–0.67)&lt;.0001 Bone only†36.2 (27.6–NE)11.2 (8.2–22.0)0.41 (0.26–0.63)&lt;.0001 Not bone only24.2 (19.4–27.7)14.5 (12.9–18.5)0.62 (0.50–0.78)&lt;.0001 De novo metastatic27.9 (22.1–33.4)22.0 (13.9–27.4)0.61 (0.44–0.85)&lt;.005 Prior ET24.2 (18.8–27.6)11.2 (8.4–14.5)0.54 (0.42–0.71)&lt;.0001 No prior ET30.3 (24.5–35.7)21.9 (15.9–27.4)0.59 (0.43–0.80)&lt;.0005 Nonvisceral36.2 (27.9–NE)27.6 (19.1–35.6)0.59 (0.38–0.92)&lt;.01 Visceral23.7 (16.8–30.3)13.9 (10.2–22.2)0.55 (0.36–0.85)&lt;.005 Disease sites130.4 (24.8–NE)16.5 (11.0–22.1)0.52 (0.36–0.75)&lt;.0005228.1 (19.4–NE)16.3 (11.0–27.4)0.57 (0.37–0.89)&lt;.01323.7 (19.2–27.6)13.8 (8.8–17.0)0.61 (0.46–0.82)&lt;.0005NE=not estimable. *Not adjusted for multiple analyses; 1-sided P values. †Per tumor site.

All subgroups benefited from addition of P to L. Notably, pts w/ low disease burden (bone only, nonvisceral disease, few disease sites) derived significant PFS benefit, including those w/ both nonvisceral disease and no prior ET (mPFS, 36.2 vs 27.6 mo; HR=0.59, P&lt;.01). Importantly, median time from randomization to start of 2nd subsequent systemic anticancer therapy was 39 vs 29 mo for P+L vs PBO+L (HR=0.72, P&lt;.005). There were no new safety signals w/ longer FU.

CONCLUSIONS: This is the longest FU of a phase 3 study of a cyclin-dependent kinase 4/6 inhibitor for ABC. P+L continues to consistently improve PFS vs PBO+L across all subgroups while toxicity remains manageable; notably P+L delays time to starting 2nd subsequent anticancer therapies by 10 mo. Pts w/ low disease burden or sensitivity to ET alone had PFS &gt;3 y (significant vs PBO+L), demonstrating the clinical benefit of P+ET. These data confirm P+L should be a 1L therapy option for pts w/ HR+/HER2- ABC.

Funding: Pfizer

Citation Format: Rugo HS, Finn RS, Dieras V, Ettl J, Lipatov O, Joy A, Harbeck N, Castrellon A, Lu DR, Mori A, Gauthier ER, Huang C, Gelmon KA, Slamon DJ. Palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Efficacy and safety updates with longer follow-up across patient subgroups [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-03.

Abstract P5-21-25: Efficacy and safety of palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Findings by geographic region from PALOMA-2

BACKGROUND: Previous findings from the PALOMA-2 study (N=666) demonstrated the efficacy and safety of PAL+LET as first-line ABC therapy versus placebo (PBO)+LET (Finn et al, NEJM. 2016). This analysis evaluated the efficacy and safety of PAL+LET by geographic region (North America [NA], Europe [EU], and Asia Pacific [AP]; data cutoff: Feb 26, 2016).

METHODS: Women with ER+/HER2– ABC who had not received prior systemic treatment in the advanced setting were randomized 2:1 to PAL (125 mg/d oral [3 wks on, 1 wk off])+LET (2.5 mg once daily) or PBO+LET.

RESULTS: This analysis included 267 patients from NA, 307 from EU, and 92 from AP. At baseline, demographics and disease characteristics generally were similar between regions. In the overall population (Table 1), PAL+LET demonstrated improvements versus PBO+LET in progression-free survival (PFS), objective response rate (ORR), and clinical benefit response rate (CBR). Similarly, PFS was longer and ORR and CBR were higher with PAL+LET versus PBO+LET in NA, EU, and AP subgroups (Table 1). All-grade treatment-emergent adverse events (AEs) (PAL+LET/PBO+LET) occurred in 99%/99% of patients in NA, 98%/92% in EU, and 100%/96% in AP. In the PAL+LET arm, neutropenia (all-grade/grade ≥3) was the most common AE in all regions. The incidence of neutropenia was numerically higher in AP (91%/84%) compared with NA (73%/65%) and EU (81%/62%). Grade 3 or 4 febrile neutropenia occurred in 4 (2%) NA patients, 4 (2%) EU patients, and no AP patients in the PAL+LET arm and in no patients in any of the regions in the PBO+LET arm.

CONCLUSIONS: PAL+LET showed improvement versus PBO+LET in PFS, ORR, and CBR in patients with ER+/HER2- ABC in NA, EU, and AP, with comparable magnitude of benefit between regions. With PAL+LET, neutropenia was the most commonly reported AE in all regions, with a numerically higher incidence reported in AP versus NA or EU; the safety profile was similar to previously reported results in the overall population.

Funding: Pfizer (NCT01740427)

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Table 1. PFS, ORR, and CBR Median PFSPFS HRORR,* %CBR,* % (95% CI), mo(95% CI)(95% CI)(95% CI)Overall Population    PAL+LET24.8 (22.1-NE)0.58 (0.46-0.72); P&lt;0.00155.3 (49.9-60.7)84.3 (80.0-88.0)PBO+LET14.5 (12.9-17.1) 44.4 (36.9-52.2)70.8 (63.3-77.5)NA    PAL+LET24.2 (17.5-NE)0.61 (0.43-0.85)54.3 (45.3-63.2)80.3 (72.3-86.8)PBO+LET13.8 (10.3-22.1) 50.6 (39.1-62.1)67.1 (55.6-77.3)EU    PAL+LET24.8 (22.1-NE)0.57 (0.41-0.80)55.6 (47.6-63.5)87.5 (81.4-92.2)PBO+LET16.5 (11.3-19.6) 38.2 (26.7-50.8)73.5 (61.4-83.5)AP    PAL+LET22.2 (19.4-25.7)0.49 (0.27-0.87)56.9 (42.2-70.7)84.3 (71.4-93.0)PBO+LET13.9 (7.4-22.0) 41.7 (22.1-63.4)75.0 (53.3-90.2)HR=hazard ratio; NE=not estimable; OR=objective response.*Confirmed OR in patients with measurable disease.

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Citation Format: Gelmon KA, Castrellon A, Joy AA, Walshe JM, Ettl J, Mukai H, Park IH, Lu DR, Mori A, Bananis E, Diéras V, Finn RS. Efficacy and safety of palbociclib (PAL) + letrozole (LET) as first-line therapy in estrogen receptor–positive (ER+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC): Findings by geographic region from PALOMA-2 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-25.

Actin-capping protein CapG is associated with prognosis, proliferation and metastasis in human glioma

Glioma is the most aggressive and malignant primary brain tumor in adults. In the present study, we identified a vital oncoprotein, capping actin protein, gelsolin-like (CapG), and investigated its roles in the prognosis, proliferation and metastasis in glioma. The mRNA and protein levels of CapG were significantly increased in human glioma, and higher CapG expression was an independent prognostic factor for predicting unfavorable prognosis. The expression level of CapG was found to be associated with several common molecular features of glioblastoma (GBM; WHO grade IV glioma) in The Cancer Genome Atlas (TCGA) cohort. When analyzing the prognosis of GBM patients according to these molecular features, we observed that the prognostic value of CapG was affected by amplification of CDK6 or EGFR. However, overexpression of CapG markedly promoted cell growth in vitro, while depletion of CapG significantly inhibited cell proliferation by blocking the cell cycle in G1/S transition. Moreover, CapG manipulation in glioma cell lines U87 and U251 showed CapG-dependent cellular migration and invasiveness. These data suggest that CapG may serve as a prognostic biomarker with potentially important therapeutic implications for glioma.

Application of AFP whole blood one-step rapid detection kit in screening for HCC in Qidong

Hepatocellular carcinoma (HCC) is a big problem in China where the Hepatitis B (HBV) infection patients are near to 120 million. Early screening and diagnosis is the key to reduce the incidence and mortality of HCC. Serum AFP detection is the main methods for diagnosis, recurrent monitoring and therapeutic evaluation of primary HCC. Hepatitis patients should detect the AFP at least once every six months to help early diagnosis of HCC. Unfortunately, most hepatitis and other liver disease patients do not test their AFP regularly. Therefore, a rapid, convenient detect kit for AFP is necessary for the hepatitis patients to test AFP at home by themselves. It will be very helpful to the HCC early screening and early diagnosis. We screened 859 individuals who were HBsAg positive and had high risk of HCC in Qidong by using two different kits, AFP one-step rapid detection kit (Shanghai Outdo Biotech) and AFP Diagnostics ELISA kit (Zhengzhou Autobio Diagnostics), and compared the results. As a result, the positive accordance rate and the negative accordance rate of AFP one-step rapid detection kit and the Autobio ELISA kit were 95.65% (22/23) and 99.40% (831/836), respectively. The total diagnose accordance rate reached up to 99.30% (853/859). The screening results showed a high accordance rate of two methods. It is so meaningful to achieve home-test and improve HCC early screening and diagnosis by using AFP one-step rapid detection kit.

Sunitinib in pancreatic neuroendocrine tumors: updated progression-free survival and final overall survival from a phase III randomized study

BACKGROUND

In a phase III trial in patients with advanced, well-differentiated, progressive pancreatic neuroendocrine tumors, sunitinib 37.5 mg/day improved investigator-assessed progression-free survival (PFS) versus placebo (11.4 versus 5.5 months; HR, 0.42; P < 0.001). Here, we present PFS using retrospective blinded independent central review (BICR) and final median overall survival (OS), including an assessment highlighting the impact of patient crossover from placebo to sunitinib.

PATIENTS AND METHODS

In this randomized, double-blind, placebo-controlled study, cross-sectional imaging from patients was evaluated retrospectively by blinded third-party radiologists using a two-reader, two-time-point lock, followed by a sequential locked-read, batch-mode paradigm. OS was summarized using the Kaplan-Meier method and Cox proportional hazards model. Crossover-adjusted OS effect was derived using rank-preserving structural failure time (RPSFT) analyses.

RESULTS

Of 171 randomized patients (sunitinib, n = 86; placebo, n = 85), 160 (94%) had complete scan sets/time points. By BICR, median (95% confidence interval [CI]) PFS was 12.6 (11.1-20.6) months for sunitinib and 5.8 (3.8-7.2) months for placebo (HR, 0.32; 95% CI 0.18-0.55; P = 0.000015). Five years after study closure, median (95% CI) OS was 38.6 (25.6-56.4) months for sunitinib and 29.1 (16.4-36.8) months for placebo (HR, 0.73; 95% CI 0.50-1.06; P = 0.094), with 69% of placebo patients having crossed over to sunitinib. RPSFT analysis confirmed an OS benefit for sunitinib.

CONCLUSIONS

BICR confirmed the doubling of PFS with sunitinib compared with placebo. Although the observed median OS improved by nearly 10 months, the effect estimate did not reach statistical significance, potentially due to crossover from placebo to sunitinib.

TRIAL REGISTRATION NUMBER

NCT00428597.

IFIT1 polymorphisms predict interferon-α treatment efficiency for hepatitis B virus infection

AIM

To investigate the association between interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) polymorphisms and interferon-α (IFNα) treatment efficiency among Chinese hepatitis B virus (HBV) infection patients.

METHODS

Two hundred and twenty five newly diagnosed chronic hepatitis B (CHB) patients were enrolled in the study. All of these patients received IFNα treatment for a course of 48 wk, and were followed up for 24 wk after the treatment was end. Clinical information about virological response, hepatitis B e antigen (HBeAg) seroconversion rate and combined response at the end of the treatment, as well as the sustained response by the time of following up 24 wk after the treatment, was collected. Four tag-single nucleotide polymorphisms (SNPs) of IFIT1 were selected and assessed for their association with these clinical outcomes.

RESULTS

At the end of the treatment, HBeAg seroconversion was observed in 27.1% patients. Thirty-six point nine percent patients achieved virological response, and 15.6% patients exhibited combined response. Sustained response was obtained in 26.2% patients. The main HBV genotype of the study was genotype B. Patients who infected with HBV genotype B or C showed better treatment efficiency, no matter which clinical outcome was considered. Among the four SNPs assessed, rs303218 (A > G) was found to be significantly associated with the end point virological response when assuming additive model [OR = 0.64 (95%CI: 0.42-0.96), P = 0.032]. Patients who carried rs303218 GG genotype had a rather higher rate of achieving virological response (response rate: 52%, OR = 0.40, 95%CI: 0.18-0.91; P = 0.028) when compared to those had AA genotype (response rate: 27%). The most significant interaction was observed in patients who had relative lower baseline aspartate transaminase. No association between SNPs and HBeAg seroconversion, combined response or sustained response was observed.

CONCLUSION

IFIT1 involves in the regulation of IFNα treatment for CHB and its polymorphism rs303218 can predict the end point virological response. The finding requires further validation.

[Extraction of sperm DNA from mixed stain by the modified differential lysis method combined with silicon bead method]

OBJECTIVE

To extract sperm DNA from mixed stain by the modified differential lysis method combined with silicon bead method and to evaluate its application value.

METHODS

Fifty-two mixed stains containing female STR genotypes detected by differential lysis method were collected. The sperm DNA was extracted by the modified method combined with silicon bead method, then genotyped with the Identifiler Kit, and compared with the results of genotyping by the conventional differential lysis method as control.

RESULTS

Of the 52 samples, 38 samples with sole male STR genotypes in all loci were detected. The detection rate of male STR genotypes was 98.08% through the modified method combined with silicon bead method.

CONCLUSION

The modified differential lysis method combined with silicon bead method can be used in extraction of sperm DNA from mixed stain.

[Exploration on human blood type case in teaching practice of genetics]

Blood type, which harbors abundant genetics meaning, is one of the most common phenotypes in human life. With the development of science and technology, its significance is unceasingly updated and new finding is increasingly emerging, which constantly attracts people to decipher the heredity mechanism of blood type. In addition to four main associated contents, i.e., Mendelian inheritance, genetic linkage, gene mutations, and chromosome abnormalities, the blood type case also covers many other aspects of the genetics knowledge. Based on the genetic knowledge context, we can interest the students and improve the teaching output in genetic teaching practice by combining with explaining ABO blood type case and heredity mechanism, expanding leucocyte groups, and introducing infrequent blood type such as Bombay blood, Rh and MN. By carrying out the related experimental teaching, we could drive the student to integrate theory with practice. In genetic experimental teaching, 80% of the students chose this optional experiment, molecular identification of ABO blood type, and it greatly interested them. Using appropriate blood type case in teaching related knowledge, organizing PPT exhi-bition and the debating discussion activities, it could provide opportunities for student to propose their own opinions, guide the student to thinking deeply, and develop their abilities to analyze and solve problem. Afterwards, students will gain in-depth comprehension about the fundamental knowledge of genetics.

XBP1 promoter polymorphism modulates platinum-based chemotherapy gastrointestinal toxicity for advanced non-small cell lung cancer patients

BACKGROUND

The X-box binding protein 1 (XBP1) is a critical transcription factor in the endoplasmic reticulum stress response, which is essential for the maintenance of cellular homeostasis. Here, we investigated whether the regulatory variant rs2269577 of the XBP1 gene influences clinical outcome in advanced non-small cell lung cancer (NSCLC) patients undergoing platinum-based chemotherapy.

PATIENTS AND METHODS

We recruited 663 Chinese patients with advanced NSCLC treated with platinum-based regimens and assessed the association between rs2269577 and clinical outcome. Subsequent functional analyses, including real-time quantitative PCR and dual-luciferase assays, were performed to explore possible molecular mechanisms.

RESULTS

The G/G genotype of rs2269577 was significantly associated with severe gastrointestinal toxicity compared with the homozygous C/C genotype (P=0.012, odds ratio=2.755), particularly in the female, performance status 0-1, and adenocarcinoma subgroups. No significant relevance was found between rs2269577 and treatment efficacy. In gastric epithelial cells, in vitro molecular analyses demonstrated that XBP1 mRNA expression levels decreased after treatment with cisplatin and the G allele of rs2269577 weakened the transcriptional activity of the XBP1 promoter.

CONCLUSION

This is the first study to evaluate the effect of XBP1 polymorphism on severe chemotherapy-related adverse outcomes in platinum-treated advanced NSCLC patients using both pharmacogenomics and functional molecular analyses.

Association of the adiponectin gene rs1501299 G>T variant, serum adiponectin levels, and the risk of coronary artery disease in a Chinese population

BACKGROUND

The present study aimed to investigate whether the single nucleotide polymorphism (SNP) 276G>T (rs1501299) of the adiponectin (ADIPOQ) gene was associated with the risk of coronary artery disease (CAD) and serum adiponectin levels in a Chinese population.

METHODS

The rs1501299 polymorphism of the ADIPOQ gene was genotyped in 438 subjects with angiographically diagnosed CAD and 443 controls. Levels of serum adiponectin were determined in 152 CAD subjects and 155 controls.

RESULTS

The CAD subjects had GT and TT genotypes more frequently, and had GG genotype less frequently than the controls. The OR increased and was significant after adjustment for known CAD risk factors. Significant difference was also observed with T allele being more frequent among the CAD subjects. The T allele at the rs1501299 polymorphism was associated with a higher risk of CAD. The mean adiponectin levels of CAD patients were lower than control subjects. No significant correlation was seen of different genotypes with serum adiponectin levels.

CONCLUSIONS

The adiponectin rs1501299 G>T variant was positively related with an increased risk of CAD, and the CAD patients had lower adiponectin levels which were not affected by the different genotypes of rs1501299 in the present study.

The obesity-related polymorphism PCSK1 rs6235 is associated with essential hypertension in the Han Chinese population

Proprotein convertase subtilisin/kexin-type 1 (PCSK1) is a prohormone convertase that has an important role in prohormone maturation including the process of prorenin to renin. We studied the association of the PCSK1 single-nucleotide polymorphism (SNP) rs6235 (encoding an S690T substitution) with essential hypertension (EH), obesity and related traits in the Han Chinese population. The rs6235 SNP in the PCSK1 gene was investigated using a case-control study design, with 1034 hypertension cases and 1112 normotensive controls. In this study, the rs6235 SNP was significantly associated with hypertension (OR=1.26, 95% CI (1.10-1.46), P=0.001); the odds ratios of GC vs GG and CC vs GG were 1.30 (95% CI (1.06-1.58), P=0.010) and 1.55 (95% CI (1.12-2.13), P=0.007), respectively. In the controls, the C-allele was associated with increased systolic (P=0.010) and diastolic (P=0.010) blood pressure levels. In all of the EH patients and EH patients without a history of renin-angiotensin-aldosterone (RAA) system-related antagonists, the C-allele was associated with increased plasma renin activity (P=0.00004 and 0.002, respectively) and aldosterone levels (P=0.018 and 0.005, respectively). The C-allele was also associated with increased body mass index (BMI) (P=0.010) in the normotensive controls. In conclusion, the PCSK1 SNP rs6235 was associated with EH and blood pressure in the Han Chinese population, and this association may be mediated by the SNP's effect on RAA levels. rs6235 was also associated with BMI in this population.

Association between fibroblast growth factor receptor 4 polymorphisms and risk of hepatocellular carcinoma

Human fibroblast growth factor receptor 4 (FGFR4) polymorphisms have recently been shown to be associated with tumor progression of various types of cancer, including cancer of the breast, colon, and prostate and sarcoma. However, their association with hepatocellular carcinoma (HCC) is unknown. We evaluated the association of FGFR4 polymorphisms with risk of HCC in a study population with HCC and with/without hepatitis B virus (HBV) infection in East China. We genotyped four FGFR4 SNPs (rs351855, rs641101, rs376618, and rs31777) in 1,451 Chinese subjects, including 711 patients with HCC, 368 controls with HBV infection and 372 controls without HBV infection, using the TaqMan genotyping assay. Unconditional logistic regression analysis was performed to evaluate associations of genotypes of each SNP with HCC risk. For the rs351855 (Arg388) locus, we observed a reduced HCC risk associated with the T variant genotypes, particularly for those whose tumors with gross portal vein tumor thrombosis (gross PVTT) (OR = 0.66; 95% confidence interval, 95% CI = 0.46-0.95 for CT + TT). Such a protective effect was also observed for those with liver cirrhosis (OR = 0.42; 95% CI = 0.20-0.88 for CT + TT). Clearly the T allele was associated with these conditions. Our findings suggest that genetic polymorphism in FGFR4 may be a marker for risk of HCC with liver cirrhosis and gross PVTT in Chinese populations.

Berberine reduces methylation of the MTTP promoter and alleviates fatty liver induced by a high-fat diet in rats

High-calorie food leads to nonalcoholic fatty liver disease (NAFLD) through dysregulation of genes involved in lipid metabolism, but the precise mechanism remains unclear. DNA methylation represents one of the mechanisms that contributes to dysregulation of gene expression via interaction with environmental factors. Berberine can alleviate fatty liver in db/db and ob/ob mice. Here, we investigated whether DNA methylation is involved in the pathogenesis of NAFLD induced by a high-fat diet (HFD) and whether berberine improves NAFLD through influencing the methylation status of promoters of key genes. HFD markedly decreased the mRNA levels encoding CPT-1alpha, MTTP, and LDLR in the liver. In parallel, DNA methylation levels in the MTTP promoter of rats with NAFLD were elevated in the liver. Interestingly, berberine reversed the downregulated expression of these genes and selectively inhibited HFD-induced increase in the methylation of MTTP. Consistently, berberine increased hepatic triglyceride (TG) export and ameliorated HFD-induced fatty liver. Furthermore, a close negative correlation was observed between the MTTP expression and its DNA methylation (at sites -113 and -20). These data indicate that DNA methylation of the MTTP promoter likely contributes to its downregulation during HFD-induced NAFLD and, further, that berberine can partially counteract the HFD-elicited dysregulation of MTTP by reversing the methylation state of its promoter, leading to reduced hepatic fat content.

Polymorphisms in phase I and phase II metabolism genes and risk of chronic benzene poisoning in a Chinese occupational population

It is widely accepted that the cytotoxicity and genotoxicity of benzene results from the action of reactive metabolites. Therefore, genetic variation in metabolic enzyme genes may contribute to susceptibility to chronic benzene poisoning (CBP) in the exposed population. Using a case-control study that included 268 benzene-poisoned patients and 268 workers occupationally exposed to benzene in South China, we aimed to investigate the association between single-nucleotide polymorphisms in genes with phase I and II of metabolism and risk of CBP. The TaqMan technique was used to detect polymorphisms of CYP1A1, CYP1A2, CYP1B1, ADH1B, EPHX1, EPHX2, NQO1, MPO, GSTP1 and UGT1A6 genes. We also explored potential interactions of these polymorphisms with lifestyle factors such as cigarette smoking and alcohol consumption. A weak positive association was found between glutathione S-transferase pi-1 (GSTP1) rs1695 polymorphism and the risk of CBP (P = 0.046), but this association was not statistically significant (P = 0.117) after adjustment for potential confounders. Further analysis showed that the risk of CBP increased in the subjects with EPHX1 GGAC/GAGT diplotype (P = 0.00057) or AGAC/GAGT diplotype (P = 0.00086). In addition, we found that alcohol drinkers with the EPHX1 rs3738047 GA + AA genotypes and non-alcohol drinkers with the GSTP1 rs1695 AA genotype tended to be more susceptible to benzene toxicity. Our results suggest that genetic polymorphisms in EPHX1 may contribute to risk of CBP in a Chinese occupational population.

Hypermethylation of hepatic Gck promoter in ageing rats contributes to diabetogenic potential

AIMS/HYPOTHESIS

Hepatic glucokinase (GCK) is a key enzyme in glucose utilisation. Downregulation of its activity is associated with insulin resistance and type 2 diabetes mellitus. However, it is unknown whether hepatic Gck expression is influenced by age and is involved in ageing-mediated diabetes, and whether the degree of methylation of the hepatic Gck promoter is correlated with the transcription of Gck. To address the question, we evaluated hepatic Gck transcription and promoter methylation in young (14 weeks), adult (40 weeks) and aged (80 weeks) rats.

METHODS

Hepatic glycogen, Gck expression and the kinase activity of GCK were measured in three age groups. The CpG methylation status was determined by both bisulphite direct sequencing and clone sequencing of the PCR amplificates of Gck promoter. The causal relationship between Gck methylation and mRNA expression was confirmed by treating rat primary hepatocytes with 5-aza-2'-deoxycytidine (5-Aza-CdR).

RESULTS

We have shown an age-associated decline in hepatic glycogen, Gck expression levels and the kinase activity of hepatic GCK. The eleven CpG sites studied displayed age-related progressive methylation changes in hepatic Gck promoter, which were confirmed by two methods: direct and clone sequencing. After 5-Aza-CdR treatment of rat primary hepatocytes, there was a fourfold increase in Gck expression.

CONCLUSIONS/INTERPRETATION

Our results demonstrate that an age-related increase in methylation is negatively associated with hepatic Gck expression, suggesting that DNA methylation could be involved in increasing age-dependent susceptibility to hepatic insulin resistance and diabetes. Thus, the epigenetic modification of the hepatic Gck promoter may represent an important marker for diabetogenic potential during the ageing process.

Fast differential interference contrast imaging combined with autocorrelation treatments to measure the heart rate of embryonic fish

To develop an accurate and convenient method for measuring the heart rate of zebra fish in vivo, a system combining fast differential interference contrast (DIC) imaging with an autocorrelation technique is established. The imaging correlation coefficient corr(i,j) between frame i, selected from the obtained time-lapse imaging series as the reference image, and any other frame j, is calculated as the time-dependent cycle course. Heat rate is determined by the cycle period of the corr with a high temporal resolution of 4 ms, achieved by fast charge-coupled device (CCD) imaging of 250 frames per second. With this high-resolution system, we find that 1-mgL cadmium not only induces the slowing of the heart rate, but also caused signs of arrhythmia in treated fish.

Glutathione S-transferases M1 and T1 polymorphisms and arsenic content in hair and urine in two ethnic clans exposed to indoor combustion of high arsenic coal in Southwest Guizhou, China

A total of 2,402 cases of arsenic-related skin lesions (as of 2002) in a few villages of China's Southwest Guizhou Autonomous Prefecture represent a unique case of endemic arseniasis related with indoor combustion of high arsenic coal. A significant difference of skin lesion prevalence was observed between two clans of different ethnicities (Hmong and Han) in one of the hyperendemic villages in this prefecture. This study was focused on a possible involvement of GST T1 and M1 polymorphisms in risk modulation of skin lesions and in the body burden of As in this unique case of As exposure. GST T1 and M1 polymorphisms were genotyped by an allele-specific PCR-based procedure. Total As contents in hair and urine samples as well as environmental samples of the homes of the two ethnic clans were analyzed. No significant deviations in the population frequencies of GST T1 and M1 0/0 genotypes or their combination were recorded between diagnosed skin lesion patients and asymptomatic individuals in both clans. Significantly higher As contents in hair and urine were observed in GSTM1 0/0 carriers, not in GSTT1 0/0 carriers. After stratified by ethnicity and gender, a statistically significant association of the GSTM1 0/0 genotype and higher As content in hair was only confirmed in the subgroups of ethnic Han clan members and all male villagers, not in ethnic Hmong clan members or in females. GST T1 and M1 homozygous deletions were not associated with an increased susceptibility to skin lesions in long-term exposure to indoor combustion of high As coal. The polymorphic status at the locus of GSTM1 might modulate individual's body burden of total As in some Chinese ethnic groups.

Arsenic-related skin lesions and glutathione S-transferase P1 A1578G (Ile105Val) polymorphism in two ethnic clans exposed to indoor combustion of high arsenic coal in one village

OBJECTIVES

A total of 2402 patients with arsenic-related skin lesions, such as hyperkeratosis, hyperpigmentation or hypopigmentation, or even skin cancer in a few villages in Southwest Guizhou Autonomous Prefecture, China represent a unique case of endemic arsenism related with indoor combustion of high arsenic coal. This study aimed to investigate the cluster of arsenism cases and the possible relevant factors including GSTP1 polymorphism in two clans of different ethnic origin living in one village for generations.

METHODS

A questionnaire-based study was performed in 170 Miao clan P members, 10 of whom had arsenic-related skin diseases, and 153 Han clan G1 members, 50 of whom had arsenic-related skin diseases. The data were checked against the registration archives since the 1980s. At the same time, arsenic concentrations in samples of coal, indoor air, drinking water, corn and chilli pepper that were once baked over the stoves for desiccation, as well as in samples of urine and hair of clan members were determined. Glutathione S-transferase P1 (GSTP1) A1578G polymorphism was genotyped by a restriction fragment length polymorphism-based procedure.

RESULTS

Arsenism morbidity in Miao clan P was significantly lower than in the neighbouring Han clan G1 [5.9 vs. 32.7%, odds ratio (OR)=0.13, 95% confidence interval (CI): 0.06-0.27, P<0.0001]. No sex differences were confirmed inside both clans. Analyses of the environmental samples indicated that Miao clan P members were exposed to higher amounts of arsenic via inhalation and food ingestion. Hair and urine samples also proved a higher arsenic body burden in ethnic Miao individuals. No corresponding differences by sex were found. Higher frequencies of combined mutant genotype G/G1578 and A/G1578 (OR=4.72, 95% CI: 2.34-9.54, P<0.0001) and of mutant allele G1578 (OR=3.22, 95% CI: 2.00-5.18, P<0.0001) were detected in diagnosed arsenism patients than in non-diseased individuals. The Miao individuals showed a lower percentage of combined mutant genotypes (30.6 vs. 52.7%, OR=0.40, 95% CI: 0.19-0.84, P=0.015) as well as of mutant allele G1578 (OR=0.46, 95% CI: 0.24-0.88, P=0.017) than their Han neighbours.

CONCLUSIONS

Genetic predisposition influences dermal arsenism toxicity. The GSTP1 A1578G (Ile105Val) status might be a susceptibility factor for arsenic-related skin lesions.

Enhancement of Intracellular Delivery of CdTe Quantum Dots (QDs) to Living Cells by Tat Conjugation

Quantum dots (QDs), as novel fluorescence probes, have shown a great potential for bio-molecular labeling and cellular imaging. To stain cellular targets, the sufficient intracellular delivery of QDs is required. In this work the tat, a typical membrane-permeable carrier peptide, was conjugated with thiol-capped CdTe QDs to form CdTe Tat-QDs, and the intracellular deliveries of CdTe QDs or CdTe Tat-QDs were compared in human hepatocellular carcinoma (QGY) cells and human breast cancer (MCF7) cells in vitro by means of confocal laser scanning microscopy. Added into the cell dishes, both QDs and Tat-QDs adhered to the outer leaflet of the plasma membrane of cells within a few minutes, but the binding amount of Tat-QDs was obviously higher than that of QDs. Then both QDs and Tat-QDs can penetrate into cells, and their cellular contents increased with incubation time but both saturated after 3 hours incubation. However the cellular levels of Tat-QDs were higher than those of QDs, with the ratio of 2.1 (+/-0.3) times in QGY cells and 1.5 (+/-0.2) times in MCF7 cells, demonstrating the enhancing effect of Tat conjugation on the intracellular delivery of QDs.

Time-Dependent Photoluminescence Blue Shift of the Quantum Dots in Living Cells: Effect of Oxidation by Singlet Oxygen

Time-dependent photoluminescence (PL) enhancement, blue shift, and photobleach were observed from the thiol-capped CdTe quantum dots (QDs) ingested in mouse myoblast cells and human primary liver cancer cells. It was revealed that the PL blue shift resulted from the photooxidation of the QD core by singlet oxygen molecules formed on the QD core surface.

An Association of UDP-Glucuronosyltransferase 2B7 C802T (His268Tyr) Polymorphism with Bladder Cancer in Benzidine-Exposed Workers in China

UDP-Glucuronyltransferase 2B7 (UGT2B7) is involved in benzidine metabolism, as demonstrated by in vitro experiments with liver slices. To evaluate the possible association of UGT2B7 gene polymorphism with bladder cancer risk for benzidine-exposed subjects, diagnosed bladder cancer cases (n = 36) who were members of a cohort of benzidine-exposed workers in the Chinese dyestuff industry were investigated. UGT2B7 polymorphism at locus C802T (His268Tyr) was detected using a PCR-RFLP based procedure. Nondiseased cohort members (156 men, 95 women) were taken as work-related control, and unexposed healthy individuals (113 men, 105 women) were taken as community control. The data showed that the polymorphism at locus UGT2B7 C802T in a general Chinese population significantly differs from that in a Caucasian population (p = 0.00018), displaying a distinctly lower frequency of T/T genotypes (9.2 vs. 25.3%), while no significant difference to a Japanese population could be detected (p = 0.17). A higher prevalence of T/T genotype carriers was found in the cancer cases, compared with unexposed healthy controls (25 vs. 9%, odds ratio [OR] 3.30, 95% confidence interval [95% CI] 1.37-7.98, p = 0.006). A higher presentation of T allele carriers in the patients group was also confirmed (46 vs. 33%, OR 1.73, 95% CI 1.05-2.87, p = 0.03). A higher portion of the T/T genotype was also observed in bladder cancer patients compared with nondiseased members of the same benzidine-exposed cohort, although some of them displayed different degrees of cellular alterations in their exfoliated urothelial cells. This study points for the first time to an association between a homozygous mutant genotype of human UDP-glucuronosyltransferase 2B7 catalyzing the biotransformation of benzidine and an elevated bladder cancer risk for formerly benzidine-exposed workers of the dyestuff industry.

[Genetic structure of Tujia as revealed by Y chromosomes]

Tujia people call themselves "Bizika", which means aboriginal. Genetic study of Tujia is virtually absent. To characterize the genetic structure of Tujia,the distribution of 14 Y haplogroups was studied in Tujia populations sampled from Enshi, Hubei (31 males) and Jishou, Hunan (68 males). A total of eight haplogroups were observed in the Enshi and Jishou populations. The haplogroup frequencies of Tujia were compared with the frequencies of other related ethnic groups, including Northern Han, Southern Han, Tibetan-Burman speaking populations,Daic and Hmong-Mien. The principal component (PC) analysis was conducted and the PCs were plotted to explore the historical migrations. In addition, partial correlation analysis was performed to study the relationship between the first three PCs and the haplogroups. The PC2 revealed a cluster of Tujia groups including Longshan,Yongshun, and Enshi with Lahu, suggesting possible interaction between Tujia and the Di-Qiang groups. However,a similarity between Han and Tujia populations, though differentiated, were also observed. We postulated, by incorporating the results of archaeological and historical evidences, that the Ba people, the ancestors of the Tujia,might be related with Di-Qiang groups and inhabited the Tujia area initially before a substantial interaction with Han and other ethnic groups.

Insulin expression in livers of diabetic mice mediated by hydrodynamics-based administration

AIM: Transfer and expression of insulin gene in vivo are an alternative strategy to improve glycemic control in type 1 diabetes. Hydrodynamics-based procedure has been proved to be very efficient to transfer naked DNA to mouse livers. The basal hepatic insulin production mediated by this rapid tail vein injection was studied to determine its effect on the resumption of glycemic control in type 1 diabetic mice.

METHODS: Engineered insulin cDNA was inserted into plasmid vectors under a CMV promoter, and transferred into STZ induced diabetic mice by hydrodynamic procedure. Glucose levels, body weight of treated mice, insulin levels, immunohistology of the liver, and quantity of insulin mRNA in the liver were assayed to identify the improvement of hyperglycemic complication after plasmid administration. Sleeping Beauty, a transposon system, was also used to prolong the insulin expression in the liver.

RESULTS: After plasmid administration, Plasma insulin was significantly increased in the diabetic mice and the livers were insulin-positive by immunostaining. At the same time the hyperglycemic complication was improved. The blood glucose levels of mice were reduced to normal. Glucose tolerance of the treated diabetic mice was improved. Body weight loss was also ameliorated. The rapid tail vein injection did not cause any fatal result.

CONCLUSION: Our results suggested that insulin gene could be efficiently transferred into the livers of diabetic mice via rapid tail vein injection and it resulted in high level of insulin expression. The basal hepatic insulin production mediated by hydrodynamics-based administration improved the glycemic control in type 1 diabetes dramatically and ameliorated diabetic syndromes. Hydrodynamics-based administration offers a simple and efficient way in the study of gene therapy for type 1 diabetes.

Transfection of mEpo gene to intestinal epithelium in vivo mediated by oral delivery of chitosan-DNA nanoparticles

AIM: To prepare the chitosan-pmEpo nanoparticles and to study their ability for transcellular and paracellular transport across intestinal epithelia by oral administration.

METHODS: ICR mice were fed with recombinant plasmid AAV-tetO-CMV-mEpo (containing mEpo gene) or pCMVβ (containing LacZ gene), whether it was wrapped by chitosan or no. Its size and shape were observed by transmission electron microscopy. Agarose gel electrophoresis was used to assess the efficiency of encapsulation and stability against nuclease digestion. Before and after oral treatmant, blood samples were collected by retro-orbital puncture, and hematocrits were used to show the physiological effect of mEpo.

RESULTS: Chitosan was able to successfully wrap the plasmid and to protect it from DNase degradation. Transmission electron microscopy showed that freshly prepared particles were approximately 70-150 nm in size and fairly spherical. Three days after fed the chitosan-pCMVβ complex was fed, the mice were killed and most of the stomach and 30% of the small intestine were stained. Hematocrit was not modified in naive and ‘naked’ mEpo-fed mice, a rapid increase of hematocrit was observed during the first 4 days of treatment in chitosan-mEpo-fed animals, reaching 60.9 ± 1.2% (P < 0.01), and sustained for a week. The second feed (6 days after the first feed) was still able to promote a second hematocrit increase in chitosan-mEpo-fed animals, reaching 65.9 ± 1.4% (P < 0.01), while the second hematocrit increase did not appear in the ‘naked’ mEpo-second-fed mice.

CONCLUSION: Oral chitosan-DNA nanoparticles can efficiently deliver genes to enterocytes, and may be used as a useful tool for gene transfer.

[Origin of Hakka and Hakkanese: a genetics analysis]

Hakka is a distinctive Han Chinese population in Southern China speaking Hakkanese. The origin of Hakka has been controversial. In this report, we analyzed Y chromosomal markers in 148 Hakka males. Principle component analysis of Y-SNP haplotype distribution shows Hakka is clusteed strongly with the Han in Northern China, and is also close to She, a Hmong-Mien-speaking population, while the general Southern Han is fairly close to Daic populations. Admixture analysis revealed that the relative genetic contribution 80.2% (Han), 13% (She) and 6.8% (Kam) in Hakka. The network of Y-STR haplotype of M7 individuals in all concerned populations suggested two possible origins of Hmong-Mien contribution in Hakka: One is from Hubei and the other is from Canton. The Kam contribution in Hakka is likely from Kan-Yue, the ancient aborigine of Kiangsi (Jiangxi). The frequency of 9bp-deletion in Region V of mitochondrial DNA of Hakka is 19.7%, which is quite close to She but far from Han. We therefore concluded that genetically the majority of Hakka gene pool shall come from North Han with She contributing the most among all non-Han groups. Regarding the Hmong-Mien character of Hakkanese, the genetic structure of Hakka shows their core may be Kim-man, the ancient Hmong-Mien. We hypothesized that a great number of Han people from North China join this population in succession. Southern Chinese dialects, such as Hakkanese may also be those languages of Southern aborigines at first, and turn to extant appearance under the continuance effect of Northern Chinese.

Construction of a recombinant vector based on AAV carrying human endothelial nitric-oxide synthase gene

AIM

To construct an AAV based vector carrying human endothelial nitric-oxide synthase (eNOS) cDNA and study its expression in vitro for future gene therapy.

METHODS

eNOS cDNA was inserted into the EcoR I site of pSNAV-1 containing the cytomegalovirus (CMV) promoter and inverted terminal repeat sequences of adeno-associated virus. The constructed vector was transfected into BHK and C2C12 cells. eNOS cDNA and mRNA were detected by polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR), respectively.

RESULTS

By restriction enzyme digestion analysis, it was proved that eNOS cDNA was inserted into pSNAV-1 in a proper direction. PCR detection demonstrated that pSNAV-eNOS was transferred into both BHK and C2C12 cells. RT-PCR analysis showed that these pSNAV-eNOS transfected cells could express eNOS mRNA.

CONCLUSION

pSNAV-eNOS was successfully constructed with the ability to express human eNOS mRNA in cultured mammalian cells.

Cell culture studies of a carborane cholesteryl ester with conventional and PEG liposomes

A new cholesterol-carborane conjugate (BCH) has been synthesized as a potential targeting agent for boron neutron capture therapy (BNCT) of cancers. The compound is extremely water insoluble and was formulated in two liposomal formulations to determine if the compound could be adequately taken up by 9L rat glioma cells in cell culture. Several factors potentially affecting the cellular uptake were evaluated, such as concentration of BCH in the incubation medium, incubation time, cell confluence, and the addition of polyethylene glycol (PEG) phospholipids to the liposomal formulation. The studies indicated that the cellular uptakes of BCH in the conventional and PEG liposomal formulations were 49.1 and 45.9 microg boron/g cells, respectively. Therefore, this compound, formulated in both liposomal formulations, delivered sufficient levels of boron to cancer cells in vitro, indicating that BCH is a promising approach for use in BNCT. The uptake appeared to depend upon BCH concentration in the media as well as the confluence of the cells. The greater boron uptake by nonconfluent cells indicated that active growth of cells was a factor in the uptake of this compound.

[Specific antibodies against recombinant MSP1 of Plasmodium falciparum strongly inhibit the parasite growth in vitro]

In order to produce large amounts of protein for vaccine trials, a synthetic msp1-42 gene was inserted into Pichia pastoris expression vector and the plasmid was introduced into Pichia pastoris SMD1168 by electroporation. The expressed MSP1-42 was secreted into the protein-free medium. To measure the conformational properties of MSP1-42,16 monoclonal antibodies (11 recognizing conformational epitopes) were allowed to interact with the Pichia-derived MSP1-42, and all antibodies specific for conserved and K1 protype interacted with the protein. Interestingly, three monoclonal antibodies (e.g. 9.8, 13.1 and 7.3), that were shown not to interact with CHO-derived MSP1, could interact with the Pichia-derived MSP1-42. Rabbits were immunized with recombinant MSP1-42 formulated with CFA adjuvant four times. The rabbits were bled on the day 3 after last immunization, and total IgG isolated by protein A column from the immunized rabbits was shown to strongly inhibit the parasite growth in vitro dose-dependently, whereas IgG from rabbit with adjuvant had no inhibition.

Cell culture and animal studies for intracerebral delivery of borocaptate in liposomal formulation

The efficacy of a liposomal formulation for intracerebral delivery of borocaptate (BSH) to brain tumor cells has been investigated using cell culture to study BSH uptake and persistence and using tumor-bearing rats to determine BSH distribution in the brain. During a 16-hr incubation, cellular uptake of BSH solution or BSH liposomal formulation was similar. However, the cellular persistence of BSH greatly increased when BSH was present in liposome. The differences in cellular persistence for BSH solution and BSH-loaded liposomes were significant both in 12-hr and 24-hr incubation experiments (p < 0.05 and p < 0.01, respectively). For the studies involving tumor-bearing rats, BSH level in tumor tissue was significantly higher than that in normal brain tissue at 2 hr and 6 hr after intracerebral injection of BSH-loaded liposomes (p < 0.01). Our study indicated that the liposomal formulation enhanced cellular persistence of BSH in tumor cells and therefore favored the boron accumulation in the cells. With the prolonged physical retention of liposomes at the local injection site and the cellular retention of BSH enhanced by the liposomes, the intracerebral delivery of BSH using liposomal formulation may provide an effective boron delivery approach for boron neutron capture therapy of brain tumors.

Adenovirus 5 E1a-mediated gene therapy for human ovarian cancer cells in vitro and in vivo

The aim of this study was to investigate therapeutic efficacy of adenovirus-mediated E1a gene therapy for ovarian cancer in vitro and in vivo. Recombinant replication-deficient adenoviral vectors were prepared by superinfection of 293 cells, and then purified. The efficacy of the adenovirus vector system to infect ovarian cells was tested using different multiplicity of infection (MOI) and different times (1-4) of Ad.RSVlacZ. SKOV-3 cells (10(3) per well) were infected once with 2 x 10(4) adenovirus. The cells were harvested and counted on different days for 7 days to generate the in vitro growth curve. Tumor-bearing mice were injected intraperitoneally with ovarian cancer cells and treated by intraperitoneal injection of 100 microl (2.5 x 10(8) PFU) viral solution containing either replication-deficient Ad.E1a(+); control virus Ad.E1a(-) which is the same adenovirus as Ad.E1a(+) except for E1a deletion, or just phosphate buffered solution. The transduction efficacy increased with higher MOI and reached a plateau at the 20:1 ratio. When Ad.E1a(+) was used to transduce the HER-2/neu overexpressing human ovarian cancer cell line SKOV-3, tumor cell growth in vitro was greatly inhibited by E1a transduction. Also, Ad.E1a+ greatly inhibited tumor growth of SKOV-3-bearing mice. Immunohistochemistry analysis indicated that Ad.E1a protein was expressed in tumor tissue and expression of HER-2/neu p185 protein was suppressed. Very strong beta-gal staining was detected in tumors, and beta-gal activity in small intestine, lung, heart, stomach, liver, and kidney was detected. No beta-gal activity was detected in the tumor and other organs in control mice injected with Ad.E1a(-) or PBS. Adenovirus-type 5 E1a gene can efficaciously inhibit HER-2/neu-overexpressing ovarian cancer, and this promising procedure could greatly benefit ovarian cancer patients with high expression of HER-2/neu.

[Study on expression and resistance of the double drug resistance genes transduced into human umbilical cord blood CD34+ cells mediated by bicistronic retroviral vector]

To explore whether human umbilical cord blood CD34+ cells transduced with human aldehyde dehydrogenase class-1 (ALDH1) and multidrug resistance gene (MDR1) increase resistance to 4-Hyaroxycyclophosphophamide (4-HC) and P-Glycoprotein Effluxed Drugs, a bicistronic Retroviral vector G1Na-ALDH1-IRES-MDR1 was constructed. The vector was transduced into the packaging cell lines GP + E86 and PA317 by LipofectAMINE. Using the medium containing VCR and 4-HC for cloning selection and pingponging supernatant infection between ecotropic producer clone and amphotropic producer clone, we obtained high titer amphotropic PA317 producer clone with the highest titer up to 5.6 x 10(5) CFU/ml. Cord blood CD34+ cells were transfectced repeatedly with supernatant of retrovirus containing human ALDH1 and MDR1cDNA under stimulation of hemopoietie growth factors. PCR, RT-PCR, Southern blot, Northern blot, FACS and MTT method analyses show that dual drug resistance genes have been integrated into the genomic DNA of cord blood CD34+ cells and expressed efficiently. The transgenes recipient cells confered 4- to 7.2-folds stronger resistance to cyclophospsphamede and P-Glycoprotein Effluxes drug in comparison with the nontransduced cells. This study provided a foundation for the application of combination chemotherapy in tumor clinical trial.

Targeted drug delivery for brain cancer treatment

The blood brain barrier (BBB) and the systemic toxicity of conventional chemotherapy present obstacles to the success of future blood-borne drug therapies of brain tumors. The work with polymer-encapsulated cancer drugs suggests an alternative and more focused treatment approach. Our experimental strategy integrates direct intracerebral drug delivery, sustained drug release from liposomes or polymer implants, and increased targeting of the drug either by chemically modifying the drug or by using tumor-specific carriers. This review will present some of the recent work on targeted drug delivery for brain cancer treatment.

[Immunization of mice with plasmid DNA against malaria and regulation of antigen expression by tetracycline-controlled promoter]

Sequence of MSP1-31 of Plasmodium falciparum was constructed into eukaryotic expression vector pTRE, which could be repressed by tetracycline (Tc) and resulted in recombinant plasmid pTRE-31. The plasmid was injected into the quadriceps muscle of BALB/c mice with Tc responsive plasmid pTet-off to measure specific antibodies. The MSP1-31 prokaryotic expressed protein was used as antigen in ELISA. Results showed that mice orally administered by Tc had a seroconversion rate of 7.1% (1/14) 4 weeks after injection, whereas the control mice had a seroconversion rate of 100% and the titers of antibody were raised continusly within 12 weeks. The study suggested that the recombinant plasmids pTRE-31/pTet-off could efficiently induce humoral response against MSP1-31 of malaria. Moreover this immune response was controlled by Tc and was reversible after withdrawal of Tc dilivery. The induction of antibody by removing Tc at the fourth week after injection indicated that DNA vaccine could remain in mice and capable of expressing antigen for at least 4 weeks.

Carboplatin-loaded PLGA microspheres for intracerebral injection: formulation and characterization

The purpose of this study is to prepare and characterize injectable carboplatin-loaded poly(D,L,-lactic-co-glycolic) acid copolymer (PLGA) microspheres for the intracerebral treatment of malignant glioma. The microspheres were prepared by an acetone/mineral oil emulsion and solvent evaporation method. Preparation variables were optimized and the following processing conditions resulted in the highest drug loading and best yields of the microspheres compared with those prepared with the other variables: the PLGA concentration was 8% (w/w) in the internal phase; the emulsifier (Span 80) concentration was 8% (w/w) in the external phase; the ratio of the internal phase: the external phase was 1:8; the stirring speed was 1500 rpm; the emulsion time was 15 min; the solvent evaporation time was 3.75 hr. Microspheres so prepared were analysed for size distribution, drug loading, in vitro release and morphological characteristics. The drug release in phosphate buffer solution started with a 10-day slow release period, followed by a fast near zero order release period from 12 to 22 days. The carboplatin release in brain homogenate was slower than in phosphate buffer solution. The morphological changes of the microspheres during the in vitro degradation correlated with the drug relase profile. In conclusion, the carboplatin-loaded PLGA microspheres were specifically prepared to meet the specification as an injectable and biodegradable brain implant.

[Splicing and stability of intron in the expression retroviral vector with human clotting factor IX]

To study the role of intron in the expression of hFIX, retroviral vectors with intron containing hFIX were constructed. It is fundamental for the intron study whether the intron constructed in retroviral vector can be steadily transferred into target cell. First, we constructed two forward-orientation retroviral vectors: G1NaC-i-IX contains the exogenous intron from IL-2, and G1NaC-i'-IX contains the truncated intron I from hFIX gene, covering the splicing donor and acceptor sequences. RT-PCR result indicated that intron in the forward-orientation retroviral vector was spliced after packaging in PA317. Then, reverse-orientation retroviral vectors G1NaC-i'-IXR and G1NaPAIXi' BAM were constructed, in which the reverse and complimentary sequences of hFIX gene with intron appeared in retroviral RNA. RT-PCR assay combined with ELISA test indicated that intron was retained after packaging and hFIX gene with intron constructed in the reverse-orientation retroviral vector can be transduced intact and expressed hFIX at a high level in vitro.

Effect of gastrointestinal protein adsorption on the in vitro release of AZT from ethylcellulose microspheres

The purpose of this study was to assess the effect of gastrointestinal proteins on the in vitro release of zidovudine (AZT) from ethylcellulose microspheres, and to investigate protein adsorption as a possible mechanism that mediates this effect. AZT release from ethylcellulose microspheres was tested in the presence of different gastrointestinal proteins, both dietary (casein and albumin) and endogenous (pepsin, pancreatin, and mucin) in simulated gastric fluid and/or simulated intestinal fluid. The resulting release profiles were compared with those produced in the corresponding release media without the presence of proteins. Protein adsorption on AZT-loaded ethylcellulose microspheres was studied for the five proteins under investigation. The amounts of adsorbed proteins were determined by fluorescent spectrometry after the protein solution was reacted with fluoraldehyde reagent. All of the investigated proteins were found to slow the release of AZT from ethylcellulose microspheres. At gastric pH, ovalbumin and casein had the maximum effect on AZT release. Mucin exerted a more pronounced effect at gastric pH compared with that at intestinal pH. The negative effect of pancreatin on AZT release increased when its concentration was increased. The five proteins were found to adsorb on AZT-loaded ethylcellulose microspheres with varying quantities. The observed protein adsorption is believed to cause blockage of the small pores and channels in the microsphere structure, and consequently slow the release of AZT.