Navigating PRKCSH's impact on cancer: from N-linked glycosylation to death pathway and anti-tumor immunity

PRKCSH, also known as Glucosidase II beta subunit (GluIIβ), is a crucial component of the endoplasmic reticulum (ER) quality control system for N-linked glycosylation, essential for identifying and eliminating misfolded proteins. Glucosidase II consists of the catalytic alpha subunit (GluIIα) and the regulatory beta subunit (GluIIβ), ensuring proper protein folding and release from the ER. The induction of PRKCSH in cancer and its interaction with various cellular components suggest broader roles beyond its previously known functions. Mutations in the PRKCSH gene are linked to autosomal dominant polycystic liver disease (ADPLD). Alternative splicing generates distinct PRKCSH isoforms, which can influence processes like epithelial-mesenchymal transition (EMT) and the proliferation of lung cancer cells. PRKCSH's involvement in cancer is multifaceted, impacting cell growth, metastasis, and response to growth factors. Additionally, PRKCSH orchestrates cell death programs, affecting both autophagy and apoptosis. Its role in facilitating N-linked glycoprotein release from the ER is hypothesized to assist cancer cells in managing increased demand and ER stress. Moreover, PRKCSH modulates anti-tumor immunity, with its suppression augmenting NK cell and T cell activity, promising enhanced cancer therapy. PRKCSH's diverse functions, including regulation of IGF1R and IRE1α, implicate it as a therapeutic target and biomarker in cancer immunotherapy. However, targeting its glucosidase II activity alone may not fully counteract its effects, suggesting broader mechanisms in cancer development. Further investigations are needed to elucidate PRKCSH's precise role and validate its therapeutic potential in cancer treatment.

Paediatric abacavir-lamivudine fixed-dose dispersible tablets and ritonavir-boosted lopinavir granules in neonates exposed to HIV (PETITE study): an open-label, two-stage, single-arm, phase 1/2, pharmacokinetic and safety trial

BACKGROUND

Existing solid antiretroviral fixed-dose combination formulations are preferred over liquid formulations in children, but their suitability for neonates is unknown. We evaluated the pharmacokinetics and safety of paediatric abacavir-lamivudine fixed-dose dispersible tablets and ritonavir-boosted lopinavir granules in neonates.

METHODS

In this open-label, two-stage, single-arm, phase 1/2, pharmacokinetic and safety trial, generic abacavir- lamivudine (120:60 mg) double-scored dispersible tablets and lopinavir boosted with ritonavir (40:10 mg) granules were studied. Neonates exposed to HIV (≥37 weeks gestational age) of no more than 3 days of age with birthweights of 2000-4000 g were identified through routine care in a tertiary hospital in Cape Town, South Africa. In stage 1, the pharmacokinetics and safety of two single doses were assessed to select the multidose strategy for stage 2. Neonates received a single dose of abacavir-lamivudine (30:15 mg, a quarter of a tablet) and lopinavir boosted with ritonavir (40:10 mg - one sachet) orally between 3 days and 14 days of age, and a second dose of a quarter tablet of abacavir-lamivudine and lopinavir boosted with ritonavir (80:20 mg, two sachets) 10-14 days later in stage 1. The multidose strategy selected in stage 2 was a quarter of the abacavir-lamivudine (30:15 mg) fixed-dose dispersible tablet once per day and two sachets of the lopinavir boosted with ritonavir (80:20 mg) granules twice per day from birth to age 28 days. In both stages two intensive pharmacokinetic visits were done, one at less than 14 days of life (pharmacokinetics 1) and another 10-14 days later (pharmacokinetics 2). Safety visits were done 1-2 weeks after each pharmacokinetic visit. Primary objectives were to assess pharmacokinetics and safety of abacavir, lamivudine, and lopinavir. Pharmacokinetic endpoints were area under the concentration time curve (AUC), maximum concentration, and concentration at end of dosing interval in all participants with at least one evaluable pharmacokinetic visit. Safety endpoints included grade 3 or worse adverse events, and grade 3 or worse treatment-related adverse events, occurring between study drug initiation and end of study. This completed trial is registered with the Pan African Clinical Trials Registry (PACTR202007806554538).

FINDINGS

Between Aug 18, 2021, and Aug 18, 2022, 24 neonates were enrolled into the trial and received study drugs. Eight neonates completed stage 1, meeting interim pharmacokinetic and safety criteria. In stage 2, 16 neonates received study drugs. Geometric mean abacavir and lamivudine exposures (AUC0-24) were higher at 6-14 days (51·7 mg × h/L for abacavir and 17·2 mg × h/L for lamivudine) than at 19-24 days of age (25·0 mg × h/L and 11·3 mg × h/L), whereas they were similar for lopinavir over this period (AUC 0-12 58·5 mg × h/L vs 46·4 mg × h/L). Abacavir geometric mean AUC0-24 crossed the upper reference range at pharmacokinetics 1, but rapidly decreased. Lamivudine and lopinavir AUC0-tau were within range. No grade 2 or worse adverse events were related to study drugs. One neonate had a grade 1 prolonged corrected QT interval using the Fridericia method that spontaneously resolved.

INTERPRETATION

Abacavir-lamivudine dispersible tablets and ritonavir-boosted lopinavir granules in neonates were safe and provided drug exposures similar to those in young infants. Although further safety data are needed, this regimen presents a new option for HIV prevention and treatment from birth. Accelerating neonatal pharmacokinetic studies of novel antiretroviral therapies is essential for neonates to also benefit from state-of-the-art treatments.

FUNDING

Unitaid.

Transcriptomic analysis of glucosidase II beta subunit (GluIIß) knockout A549 cells reveals its roles in regulation of cell adhesion molecules (CAMs) and anti-tumor immunity

Glucosidase II beta subunit (GluIIß), encoded from PRKCSH, is a subunit of the glucosidase II enzyme responsible for quality control of N-linked glycoprotein folding and suppression of GluIIß led to inhibitory effect of the receptor tyrosine kinase (RTKs) activities known to be critical for survival and development of cancer. In this study, we investigated the effect of GluIIß knockout on the global gene expression of cancer cells and its impact on functions of immune cells. GluIIß knockout lung adenocarcinoma A549 cell line was generated using CRISPR/Cas9-based genome editing system and subjected to transcriptomic analysis. Among 23,502 expressed transcripts, 1068 genes were significantly up-regulated and 807 genes greatly down-regulated. The KEGG enrichment analysis showed significant down-regulation of genes related extracellular matrix (ECM), ECM-receptor interaction, cytokine-cytokine receptor interaction and cell adhesion molecules (CAMs) in GluIIß knockout cells. Of 9 CAMs encoded DEG identified by KEGG enrichment analysis, real time RT-PCR confirmed 8 genes to be significantly down-regulated in all 3 different GluIIß knockout clones, which includes cadherin 4 (CDH4), cadherin 2 (CDH2), versican (VCAN), integrin subunit alpha 4 (ITGA4), endothelial cell-selective adhesion molecule (ESAM), CD274 (program death ligand-1 (PD-L1)), Cell Adhesion Molecule 1 (CADM1), and Nectin Cell Adhesion Molecule 3 (NECTIN3). Whereas PTPRF (Protein Tyrosine Phosphatase Receptor Type F) was significantly decreased only in 1 out of 3 knockout clones. Microscopic analysis revealed distinctively different cell morphology of GluIIβ knockout cells with lesser cytoplasmic and cell surface area compared to parental A549 cells and non-targeted transfected cells.Further investigations revealed that Jurkat E6.1 T cells or human peripheral blood mononuclear cells (PBMCs) co-cultured with GluIIß knockout A549 exhibited significantly increased viability and tumor cell killing activity compared to those co-cultured with non-target transfected cells. Analysis of cytokine released from Jurkat E6.1 T cells co-cultured with GluIIß knockout A549 cells showed significant increased level of angiogenin and significant decreased level of ENA-78. In conclusion, knockout of GluIIß from cancer cells induced altered gene expression profile that improved anti-tumor activities of co-cultured T lymphocytes and PBMCs thus suppression of GluIIß may represent a novel approach of boosting anti-tumor immunity.

Small RNA Deep Sequencing of Circulating Small RNAs Discovers a Unique Panel of microRNAs as Feasible and Reliable Biomarkers of Non-Small Cell Lung Cancers in Northern Thailand

OBJECTIVE

This study aimed to assess the practicality and reliability of utilizing microRNAs (miRNAs) as a potential screening and diagnosing tool for non-small cell lung cancers (NSCLCs) in Northern Thailand.

METHODS

Small RNA sequencing and a literature review was performed to obtain a list of serum miRNA candidates. Serum levels of these selected miRNA candidates were measured in patients with NSCLC and healthy volunteers by real-time RT-PCR and receiver operating characteristic curve (ROC) were used to assess diagnostic performance.

RESULTS

Sequencing data revealed 148 known miRNAs and 230 novel putative miRNAs in serum samples; 19 serum miRNAs were significantly downregulated and 242 were upregulated. Seven miRNAs selected according to sequencing data and 11 miRNAs according to previous reports were evaluated in training cohort (45 lung cancer patients, 26 controls) and 6 miRNAs were found differentially expressed (p < 0.05, Mann Whitney U test) and associated (p < 0.05, Chi-square test) with NSCLC development. Further analysis and verification identified an optimal combination of 4 miRNAs composed of hsa-miR23a, hsa-miR26b, hsa-miR4488 and novel-130 to provide the optimal AUC of 0.901±0.034. Detection of serum miRNA by real-time RT-PCR showed good reproducibility with the coefficient of variation (CV) ≤ 4%. The optimal screening miRNAs panel was primarily identified through sequencing data of local patient population, thus indicating that the etiology of NSCLCs may differ from one population to other and thus require a unique panel of miRNAs for their identification.

CONCLUSION

Circulating miRNA is a feasible screening tool for NSCLCs. Nevertheless, populations with different lung cancer etiology may need to identify their own most suitable miRNA panel.

Tenofovir-Diphosphate in Dried Blood Spots versus Tenofovir in Urine/Plasma for Oral Preexposure Prophylaxis Adherence Monitoring

Background

Tenofovir-diphosphate (TFV-DP) measured in dried blood spots (DBS) and tenofovir (TFV) measured in urine/plasma have been used to measure TFV-based oral pre-exposure prophylaxis (PrEP) adherence. However, there are limited data comparing these 3 metrics and their appropriate use for PrEP adherence monitoring.

Methods

We collected DBS, urine, and plasma samples from HIV-negative adults randomized to a low (2 doses/week), moderate (4 doses/week), or perfect (7 doses/week) adherence group (via directly observed therapy) of tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) for 6 weeks, followed by a 4-week washout phase. Drug concentrations were measured using liquid chromatography tandem mass spectrometry. Linear mixed-effects modeling was used to examine associations between drug concentrations and dosing time.

Results

Among 28 participants, the median age was 33 years, and 12 (43%) were female. At steady state, 25th percentile TFV-DP concentrations were 466, 779, and 1375 fmol/3 mm punch in the low, moderate, and perfect adherence group, respectively. Correlation was stronger between quantifiable TFV-DP and plasma TFV (r = 0.65; P < .01) than between TFV-DP and urine TFV (r = 0.50; P < .01). Among all participants, each additional week of cumulative dosing on average led to a mean increase of 158 fmol/3 mm punch (P < .001) in TFV-DP during the dosing phase. Each additional day after the last dose was associated with 43 fmol/3 mm punch lower TFV-DP (P = .07).

Conclusions

TFV-DP levels in DBS provide valuable insight into both dosing recency and cumulative doses from variable adherence patterns. Our observed benchmark TFV-DP concentrations were slightly higher than prior predicted estimates based on convenience samples.

Pharmacokinetics and Safety of the Abacavir/Lamivudine/Lopinavir/Ritonavir Fixed-Dose Granule Formulation (4-in-1) in Neonates: PETITE Study

BACKGROUND

Antiretroviral options for neonates (younger than 28 days) should be expanded. We evaluated the pharmacokinetics, safety, and acceptability of the "4-in-1" fixed-dose pediatric granule formulation of abacavir/lamivudine/lopinavir/ritonavir (30/15/40/10 mg) in neonates.

METHODS

The PETITE study is an ongoing phase I/II, open-label, single-arm, 2-stage trial conducted in South Africa. In stage 1, term neonates exposed to HIV on standard antiretroviral prophylaxis (nevirapine ± zidovudine) received single dose(s) of the 4-in-1 formulation, followed by intensive pharmacokinetic sampling and safety assessments. At each PK visit, blood was drawn after an observed dose at 1, 2, 4, 8, and 12 hours postdose. In this study, we have reported the planned interim pharmacokinetic and safety analysis after completion of the single-dose administration.

RESULTS

Sixteen neonates, with a median (range) birth weight of 3130 g (2790-3590 g), completed 24 pharmacokinetic visits. The 4-in-1 formulation imposed relatively high doses of abacavir [8.6 mg/kg (6.6-11.4)] and lamivudine [4.3 mg/kg (3.3-5.7)] but lower doses of lopinavir [11.5 mg/kg (8.8-15.2)]. The geometric means (GM, 90% CI) AUC0-12 of abacavir, lamivudine, and lopinavir were 29.87 (26.29-33.93), 12.61 (10.72-14.83), and 3.49 (2.13-5.72) µg.h/mL, respectively. Lopinavir GM AUC0-12 was below the predefined target (20-100 µg.h/mL), and ritonavir concentrations were only detectable in 4 of the 120 (3%) samples. No adverse events were related to study drugs. No neonate had difficulty swallowing the 4-in-1 formulation.

CONCLUSIONS

The high doses of abacavir and lamivudine (in mg/kg) and AUCs were safe, and the formulation was well tolerated; however, lopinavir/ritonavir exposures were extremely low, preventing its use in neonates use in neonates. Alternative pediatric solid antiretroviral formulations must be studied in neonates.

Proximal tubular dysfunction in pregnant women receiving tenofovir disoproxil fumarate to prevent mother-to-child transmission of hepatitis B virus

BACKGROUND

Data evaluating the risk of proximal tubular dysfunction in women receiving tenofovir disoproxil fumarate for the prevention of mother-to-child transmission (PMTCT) of HBV are scarce.

OBJECTIVES

To assess the risk of proximal tubulopathy in pregnant women receiving tenofovir disoproxil fumarate for PMTCT of HBV.

PATIENTS AND METHODS

We used urine samples collected from HBV monoinfected pregnant women who participated in a Phase III, multicentre, randomized, double-blind, placebo-controlled clinical trial assessing a tenofovir disoproxil fumarate short course from 28 weeks gestational age (28-wk-GA) to 2 months post-partum (2-months-PP) for PMTCT of HBV in Thailand. Markers of tubular dysfunction, including retinol binding protein, kidney injury molecule-1, α1-microglobuin and β2-microglobulin, were assayed at 28- and 32-wk-GA and 2-months-PP visits. Proximal tubulopathy was defined as the presence of ≥2 of the following: tubular proteinuria, euglycaemic glycosuria and increased urinary phosphate.

RESULTS

A total of 291 women participated in the study. No kidney-related adverse events were severe, and none led to tenofovir disoproxil fumarate discontinuation. At 2-months-PP, 3 of the 120 (3%) evaluated women in the tenofovir disoproxil fumarate group experienced proximal tubulopathy versus 3 of 125 (2%) in the placebo group (P  = 1.00). None of the six women met the criteria for proximal tubulopathy at 12-months-PP but proteinuria persisted in three of them. No growth abnormalities were found at 1 year of age in infants born to mothers with proximal tubulopathy at 2-months-PP.

CONCLUSIONS

In these HBV-infected pregnant and breastfeeding women, tenofovir disoproxil fumarate administered from 28-wk-GA to 2-months-PP was not associated with a higher risk of proximal tubulopathy.

Plasma pharmacokinetics and urinary excretion of tenofovir following cessation in adults with controlled levels of adherence to tenofovir disoproxil fumarate

OBJECTIVES

The aim was to fully characterize the plasma and urine washout pharmacokinetics of tenofovir (TFV) in adults following 6 weeks of controlled levels of tenofovir disoproxil fumarate (TDF) adherence, in order to inform the utility of clinic-based adherence testing.

DESIGN

This was a three-arm, randomized, open-label study in adult volunteers. Participants were randomized to receive TDF 300 mg/emtricitabine (FTC) 200 mg as (1) 7 doses/week (perfect adherence), (2) 4 doses/week (moderate adherence), or (3) 2 doses/week (low adherence). Plasma and urine samples were collected regularly during the 6-week dosing phase and for 4 weeks following drug cessation.

RESULTS

Twenty-eight adults were included in this analysis. Median (range) age was 33 (20-49) years. No differences in TFV pharmacokinetic parameters during the washout were observed across the study arms. Small differences in TFV plasma concentrations occurred across arms between 4 and 10 h post-dose. The cumulative amount of TFV excreted in urine was not different at 24 h post-dose, but at 148 h it was 24.8 mg, 21.0 mg, and 17.2 mg for the perfect, moderate, and low adherence arms, respectively (p = 0.043).

CONCLUSIONS

Among adults with different TDF adherence patterns, relative differences in plasma concentrations and cumulative urine extraction of TFV were minor following cessation. TFV measurement in plasma or urine is more indicative of last drug ingestion, rather than prior dose patterns.

Urine Tenofovir Concentrations Correlate With Plasma and Relate to Tenofovir Disoproxil Fumarate Adherence: A Randomized, Directly Observed Pharmacokinetic Trial (TARGET Study)

BACKGROUND

Direct measurement of tenofovir (TFV) in urine could be an objective measure to monitor adherence to preexposure prophylaxis (PrEP) or TFV-based antiretroviral therapy (ART).

METHODS

We conducted a 3-arm randomized, pharmacokinetic study of tenofovir disoproxil fumarate (TDF) 300 mg/emtricitabine (FTC) 200 mg among adults living with human immunodeficiency virus. Participants were randomized to receive controlled TDF/FTC dosing as (1) "perfect" adherence (daily); (2) "moderate" adherence (4 doses/week); or (3) "low" adherence (2 doses/week). We obtained trough spot urine and plasma samples during a 6-week directly observed therapy period and a 4-week washout period. TFV concentrations were compared between adherence arms using 1-way analysis of variance.

RESULTS

Among 28 participants, the median age was 33 years and 16 (57%) were male. Correlation between TFV plasma and urine concentrations was strong (ρ = 0.78; P < .0001). Median (interquartile range) steady-state trough TFV concentrations (ng/mL) for perfect, moderate, and low TDF adherence were 41 (26-52), 16 (14-19), and 4 (3-5) in plasma; and 6480 (3940-14 300), 3405 (2210-5020), and 448 (228-675) in urine. Trough TFV concentrations at steady state were significantly different between the 3 adherence arms for plasma (P < .0001) and urine (P = .0002). Following drug cessation, TFV concentrations persisted longer in urine than plasma samples. Washout urine TFV concentrations and time to undetectable concentrations did not differ between the 3 randomized adherence groups.

CONCLUSIONS

Urine TFV concentrations can inform interpretation of novel point-of-care urine-based TFV assays to assess recent TDF adherence.

CLINICAL TRIALS REGISTRATION

NCT03012607

Glucosidase II beta subunit (GluIIβ) plays a role in autophagy and apoptosis regulation in lung carcinoma cells in a p53-dependent manner

PURPOSE

Glucosidase II plays a major role in regulating the post-translational modification of N-linked glycoproteins. Previously, we found that the beta subunit of glucosidase II (GluIIβ) levels are significantly increased in lung carcinoma tissues, indicating a potential role in lung tumorigenesis. Here, we investigated the role of GluIIβ in the regulation of autophagy and apoptosis in lung carcinoma- and immortalized human bronchial epithelial-derived cells.

METHODS

A selective glucosidase II inhibitor, bromoconduritol, was used to inhibit GluII enzyme activity and a siRNA-based technology was used to suppress the expression of the GluIIβ encoding gene PRKCSH in lung carcinoma cells differing in p53 status. Cell viability was assessed using a MTT assay, cell cycle progression was assessed using flow cytometry, autophagy was assessed using Western blotting and apoptosis was assessed using an annexin V-FITC/PI double labeling method.

RESULTS

We found that GluIIβ inhibition resulted in the induction of autophagy in all cell lines tested, but apoptosis in only wild-type p53 cells. We also found that GluIIβ inhibition dose-dependently decreased activation of the EGFR/RTK and PI3K/AKT signaling pathways. Although the apoptosis inducing effect of GluIIβ inhibition appeared to be p53-dependent, we found that a combined treatment with lysosomal inhibitors to block autophagy enhanced the apoptotic effect of GluIIβ inhibition in both wild-type p53 and p53-null cells.

CONCLUSIONS

Our data indicate that GluIIβ inhibition results in autophagy and apoptosis in lung carcinoma-derived cells, supporting the hypothesis that this enzyme may play a role in blocking these two tumor suppressive processes. Since blocking autophagy by lysosomal inhibitors enhanced the apoptosis-inducing effect of bromoconduritol, independent of p53 status, their combined use may hold promise for the treatment of cancer, particularly lung cancer.

A randomized clinical pharmacokinetic trial of Tenofovir in blood, plasma and urine in adults with perfect, moderate and low PrEP adherence: the TARGET study

BACKGROUND

Tenofovir disoproxil fumarate (TDF) is key component of pre-exposure prophylaxis (PrEP) and antiretroviral therapy (ART) for HIV, but existing tools to monitor drug adherence are often inaccurate. Detection of tenofovir (TFV) in accessible biological samples, such as fingerprick blood, urine or oral fluid samples could be a novel objective measure of recent TDF adherence. To measure TFV concentrations associated with different levels of TDF adherence, we designed a randomized clinical trial to assess the blood, urine and oral fluid concentrations of TFV in adults with perfect, moderate and low drug adherence.

METHODS/DESIGN

A randomized, open-label, clinical pharmacokinetic study of tenofovir in healthy adult volunteers without HIV or Hepatitis B infection in Thailand. Consenting, eligible participants are randomized (1:1:1) among three groups to receive a controlled number of TDF (300 mg) doses in a combination pill with emtricitabine (FTC, 200 mg) for six weeks. Participants in Group 1 receive a single TDF/FTC tablet once daily (Perfect adherence); Group 2 receive a single TDF/FTC tablet 4 times/week (Moderate adherence); and Group 3 receive a single TDF/FTC tablet 2 times/week (Low adherence). Blood, plasma, urine and oral fluid samples are collected for drug measurement during three study phases: (i) initial 6-week treatment phase; (ii) intensive 24-h blood sampling phase after 6 weeks; (iii) 4-week washout phase. Thirty adults with evaluable pharmacokinetic samples (10 per group) will be enrolled [based on ensuring 25% precision in pharmacokinetic parameter estimates]. Pre-dose drug concentrations during the treatment phase will be descriptive and comparisons between groups performed using a Kruskal-Wallis test. A non-compartmental pharmacokinetic analysis will be performed on the intensive sampling data at Week 7 and the time course of TFV washout in the difference biological matrices will be reported based on the detected concentrations following drug cessation.

DISCUSSION

The results of this randomized trial will define the target concentration thresholds of TFV in blood, urine and oral fluid that can distinguish between different levels of TDF adherence. Such adherence 'benchmarks' can be applied to real-time drug testing and novel point-of-care tests to identify individuals with poor PrEP or ART adherence.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT03012607 .

Daily consumption of banana marginally improves blood glucose and lipid profile in hypercholesterolemic subjects and increases serum adiponectin in type 2 diabetic patients

In this study, we explored the effects of consumption of banana in thirty hypercholesterolemic and fifteen type 2 diabetic subjects. They were given a daily dose of 250 or 500 grams of banana for breakfast for 12 weeks. Fasting serum lipid, glucose and insulin levels were measured initially as well as every 4 weeks. Daily consumption of banana significantly lowered fasting blood glucose (from 99 ± 7.7 to 92 ± 6.9 and 102 ± 7.3 to 92 ± 5.7 mg x dL(-1) (p < 0.05) after consuming banana 250 or 500 g/day for 4 wk, respectively) and LDL-cholesterol/HDL-cholesterol ratio (from 2.7 ± 0.98 to 2.4 ± 0.85 and 2.8 ± 0.95 to 2.5 ± 0.79, p < 0.005) in hypercholesterolemic volunteers. Analysis of blood glycemic response after eating banana showed significantly lower 2 h-postprandial glucose level compared to baseline in hypercholesterolemic volunteers given a dose of 250 g/day. The changes of blood glucose and lipid profile in diabetic patients were not statistically significant, but for plasma levels of adiponectin, there were significantly increased (from 37.5 ± 9.36 to 48.8 ± 7.38 ngnml1, p < 0.05) compared to baseline. Although it remains to be confirmed with larger group of volunteers, this pilot study has demonstrated that daily consumption of banana (@ 250 g/day) is harmless both in diabetic and hypercholesterolemic volunteers and marginally beneficial to the later.

Glucosidase II exhibits similarity to the p53 tumor suppressor in regards to structure and behavior in response to stress signals: a potential novel cancer biomarker

Early diagnosis of cancer is a key factor for the success of treatment. For this reason, identification of highly sensitive and specific novel tumor markers is urgently needed. In the present study, the CM5 polyclonal antibody (CM5 pAb) raised against p53 of mouse origin was used to identify p53 structurally related protein(s) that may also play an important role in promoting or preventing lung cancer. Western blot analysis was performed on tumor tissues and corresponding normal tissues obtained from lung cancer patients. CM5 pAb reacted with a human protein with an apparent molecular weight of 90 kDa in the lung tumor tissue. The levels of this protein were greatly increased in 35 of the 37 (94.6%) lung tumor samples assessed, with only minimal expression in the normal adjacent tissues. The 90-kDa protein was immunoprecipitated by CM5 pAb and was subsequently identified by LC-MS/MS to be glucosidase II, a key protein involved in the quality control mechanism of glycoprotein folding. An investigation of the response to genotoxic stress and endoplasmic reticulum (ER) stress using A549 human lung adenocarcinoma cells demonstrated that glucosidase II exhibited a similar pattern of response as the p53 tumor suppressor. Protein levels of both p53 and glucosidase II were increased in response to UV irradiation but decreased in response to tunicamycin-induced ER stress. In conclusion, we demonstrated that a polyclonal antibody raised against mouse p53 could cross-react with human glucosidase II, which was found to be frequently overexpressed in human lung tumor tissues and exhibited a stress response similar to p53. The high frequency of glucosidase II overexpression, which to the best of our knowledge has not been previously described, indicates its crucial roles in lung tumorigenesis and is thus a valuable biomarker for facilitating the screening and/or diagnosis of lung cancer. However, further investigations concerning its relationship to p53 and its roles in ER and genotoxic stress are warranted.

Effect of combined genetic polymorphisms on lung cancer risk in northern Thai women

Lung cancer is a major cause of cancer-related death in developed countries, and its incidence in developing countries is increasing. In Thailand, cancer incidences differ greatly from region to region, and lung cancer is the most common cancer in the northern Thai population. The polymorphic frequency of 10 genetic susceptibility genes and their association with lung cancer were examined in a northern Thai population: CYP1A1 (MspI), CYP1A1 (Ile462Val), CYP2E1 (PstI), CYP2E1 (DraI), GSTM1, GSTT1, MPO (AciI), OGG1 (Ser326Cys), TP53 (Arg72Pro), and MMP1(AluI). The 173 subjects were 91 lung cancer patients and 82 healthy volunteers. Although no significant association between any single genetic variant and lung cancer risk was observed, when genetic variants were analyzed in combination, a significant effect on lung cancer risk was found for the variant allele in a combination of five genes involved in oxidative stress and inflammatory response: GSTM1 (null), MPO (-463A), OGG1 (326Cys), TP53 (72Pro) (alias p53), MMP1 (2G). With a reference group of individuals carrying at least two wild-type genotypes of these five genes, it was found that an individual carrying three or more variant genotypes is at significantly higher risk of developing lung cancer with the increasing of odds ratios (OR) in concurrence with the number of variant genes. The OR was 2.41 (95% CI = 0.76-7.64), 3.90 (95% CI = 1.23-12.34), and 5.20 (95% CI = 1.31-20.54) for individuals carrying three, four, and five variants, respectively. After stratifying by sex, the OR was higher for women: OR 4.05 (95% CI = 0.44-36.94), 9.00 (95% CI = 0.95-84.89) and 18.00 (95% CI = 1.49-216.62) for three, four, and five variant genotypes, respectively. This augmented effect on lung cancer risk of variant genes involved in oxidative stress and inflammatory response in women with a low prevalence of smoking indicates their modifying effect on other risk factors, such as environmental cigarette smoke, air pollution, radon radiation, or infection of the airway. Confirmation would require further investigations with larger sample sizes.

Simplified approaches for the development of an ELISA to detect circulating autoantibodies to p53 in cancer patients

Background

The recognition that human tumors stimulate the production of autoantibodies has initiated the use of this immune response as serological markers for the early diagnosis and management of cancer. The enzyme-linked immunosorbent assay (ELISA) is the most common method used in detecting autoantibodies, which involves coating the microtiter plate with the tumor associated antigen (TAA) of interest and allowing serum antibodies to bind. The patient's sample is directly in contact with the coating antigen so the protein used for coating must be pure to avoid non-specific binding. In this study, a simplified method to selectively and specifically immobilize TAAs onto microtiter plates in order to detect circulating autoantibodies in cancer patients without prior purification process was described. Wild type full-length p53 protein was produced in fusion with biotin carboxyl carrier peptide (BCCP) or hexahistidine [(His)6] using pAK400 and pET15b(+) vectors, respectively. The recombinant p53 fusion protein produced was then subjected to react with either a commercial p53 monoclonal antibody (mAb) or sera from lung cancer patients and healthy volunteers in an enzyme-linked immunosorbent assay (ELISA) format.

Results

Both of the immobilized p53 fusion proteins as well as the purified (His)6-p53 fusion protein had a similar dose response of detection to a commercial p53 mAb (DO7). When the biotinylated p53-BCCP fusion protein was used as an antigen to detect p53 autoantibodies in clinical samples, the result showed that human serum reacted strongly to avidin-coated microwell even in the absence of the biotinylated p53-BCCP fusion protein, thus compromised its ability to differentiate weakly positive sera from those that were negative. In contrast, the (His)6-p53 protein immobilized directly onto Ni+ coated microplate was able to identify the p53 autoantibody positive serum. In addition, its reactivity to clinical serum samples highly correlated with those obtained from using purified p53 as an antigen (R = 0.9803, p < 0.0001). Moreover, this directly immobilized p53 antigen can clearly differentiate p53 autoantibody positive sera in cancer patients from healthy volunteers' sera.

Conclusion

A method of coating directly and specifically TAAs onto a microtiter plate without the purification processes was developed in this study. Although in this study only one tumor antigen was examined, the simplicity and the ability of coated antigens to identify p53 specific autoantibodies in serum accurately might enable a larger panel of TAAs specific autoantibodies to be explored as serological markers for cancer.

Expression of cyclooxygenase-2 in colorectal adenocarcinoma is associated with p53 accumulation and hdm2 overexpression

Elevated cyclooxygenase-2 (COX-2) expression has been observed in various types of cancer. Induction of COX-2 expression has been reported to increase invasiveness and angiogenesis of tumours. While COX-2 overexpression has been repeatedly proven to promote tumor growth, little is known about what initiates its induction. There has been evidence to suggest that COX-2 expression is normally suppressed by wild-type p53 but not mutant p53, suggesting that loss of p53 function may result in the induction of COX-2 expression. Loss of p53 function is not only caused by gene mutation, but also through the overexpression of its negative regulator, so called human double minute 2 (hdm2). The aim of this study was to examine the correlation between COX-2 overexpression, p53 accumulation and HDM2 overexpression, as indications of p53 anomalies, and their relationship to clinicopathologic features of colorectal adenocarcinoma. Tumor tissues and the adjacent normal mucosa were obtained from 73 colorectal cancer patients who underwent curative resection at Maharaj Nakorn Chiang Mai Hospital. Protein levels of COX-2, p53 and HDM2 were determined by Western blot analysis. No normal colorectal tissues possessed detectable levels of COX-2, p53 or HDM2. In contrast, 38.3% (28 cases), 54.8% (40 cases) and 8.2% (6 cases) of tumour tissues were found to express COX-2, p53 and HDM2, respectively. Interestingly, there was a significantly positive relationship between COX-2 overexpression and p53 accumulation and/or HDM2 overexpression (P=0.007). Higher COX-2 overexpression was observed in p53-accumulated or HDM2 overexpressed-tumours (22/43 cases, 51.1%) in comparison to tumours with no evidence of p53 and HDM2 alterations (6/30 cases, 20%). The results obtained from this study indicate that overexpression of COX-2 is frequently associated with p53 protein accumulation and HDM2 overexpression, therefore the COX-2 overexpression observed in colorectal cancer cells may be partly due to the dysfunction of p53. Although mutation of p53 has been previously reported to be associated with COX-2 induction, to our knowledge, this is the first study to show the relationship between HDM2 overexpression and COX-2 overexpression.

Alteration of protein expression pattern of vascular endothelial growth factor (VEGF) from soluble to cell-associated isoform during tumourigenesis

Background

Vascular endothelial growth factor (VEGF) is a potent mitogen for endothelial cells, and its expression has been correlated with increased tumour angiogenesis. Although numerous publications dealing with the measurement of circulating VEGF for diagnostic and therapeutic monitoring have been published, the relationship between the production of tissue VEGF and its concentration in blood is still unclear. The aims of this study were to determine: 1) The expression pattern of VEGF isoforms at the protein level in colorectal and lung adenocarcinoma in comparison to the pattern in corresponding adjacent normal tissues 2) The relationship between the expression pattern of VEGF and total level of circulating VEGF in the blood to clarify whether the results of measuring circulating VEGF can be used to predict VEGF expression in tumour tissues.

Methods

Ninety-four tissue samples were obtained from patients, 76 colorectal tumour tissues and 18 lung tumour tissues. VEGF protein expression pattern and total circulating VEGF were examined using western blot and capture ELISA, respectively.

Results

Three major protein bands were predominately detected in tumour samples with an apparent molecular mass under reducing conditions of 18, 23 and 26 kDa. The 18 kDa VEGF protein was expressed equally in both normal and colorectal tumour tissues and predominately expressed in normal tissues of lung, whereas the 23 and 26 kDa protein was only detected at higher levels in tumour tissues. The 18, 23 and 26 kDa proteins are believed to represent the VEGF₁₂₁, the VEGF₁₆₅ and the VEGF₁₈₉, respectively. There was a significant correlation of the expression of VEGF₁₆₅ with a smaller tumour size maximum diameter <5 cm (p < 0.05), and there was a significant correlation of VEGF₁₈₉ with advanced clinical stage of colorectal tumours. The measurement of total circulating VEGF in serum revealed that cancer patients significantly (p < 0.001) possessed a higher level of circulating VEGF (1081 ± 652 pg/ml in colorectal and 1,251 ± 568 pg/ml in lung) than a healthy volunteer group (543 ± 344 pg/ml). No correlation between the level of circulating VEGF and the pathologic features of tumours was observed.

Conclusion

Our findings indicate that the expression patterns of VEGF isoforms are altered during tumourigenesis as certain isoform overexpression in tumour tissues correlated with tumour progression indicating their important role in tumour development. However, measurement of VEGF in the circulation as a prognostic marker needs to be carefully evaluated as the cell-associated isoform (VEGF₁₈₉), but not the soluble isoform (VEGF₁₂₁ and VEGF₁₆₅) appears to play important role in tumour progression.

Expression of cyclooxygenase-1 and -2 and clinicopathologic features of colorectal cancer in northern Thailand

Two isoforms of cyclooxygenase, COX-1 and COX-2, have been identified and shown to be involved in tumorigenesis. Although, overexpression of COX-2 in human cancers has been repeatedly reported, no data have hitherto been available for Thai patients. To cast light on the role(s) of COX enzymes in the development and progression of colorectal cancers and to determine the incidence of COX-2 overexpression, the expression levels of COX-1 and COX-2 proteins using Western blot analysis in tumor tissues and adjacent normal tissues obtained from 44 Thai patients with colorectal cancer. Compared with paired normal tissues, COX-2 was overexpressed in 13 of 44 colorectal tumor tissues (29.5%). Overall, COX-2 levels in colorectal tumor specimens were significantly correlated with histological differentiation, in particular in the tumors with poor differentiation (p<0.05). In addition, overexpression of COX-2 was found more frequently in colorectal tumors with lymphatic invasion, regional lymph node metastasis and larger size, although without statistical significance. In contrast to the relatively consistent alteration in COX-2 expression, the level of COX-1 expression was quite varied in tumor tissues. Forty-eight percent of colorectal tumors exhibited a decreased level of COX-1 in comparison to normal tissues and overexpressed in 23%. Thus both isoforms may both play roles in promoting tumorigenesis. However, there was no significant relationship between the alteration of COX-1 protein levels and any pathological features of tumors.

The health effects of swimming in ocean water contaminated by storm drain runoff

Waters adjacent to the County of Los Angeles (CA) receive untreated runoff from a series of storm drains year round. Many other coastal areas face a similar situation. To our knowledge, there has not been a large-scale epidemiologic study of persons who swim in marine waters subject to such runoff. We report here results of a cohort study conducted to investigate this issue. Measures of exposure included distance from the storm drain, selected bacterial indicators (total and fecal coliforms, enterococci, and Escherichia coli), and a direct measure of enteric viruses. We found higher risks of a broad range of symptoms, including both upper respiratory and gastrointestinal, for subjects swimming (a) closer to storm drains, (b) in water with high levels of single bacterial indicators and a low ratio of total to fecal coliforms, and (c) in water where enteric viruses were detected. The strength and consistency of the associations we observed across various measures of exposure imply that there may be an increased risk of adverse health outcomes associated with swimming in ocean water that is contaminated with untreated urban runoff.

Fossil Parasitic Copepods from a Lower Cretaceous Fish

Well-preserved Lower Cretaceous fossil copepods related to the super-family Dichelesthioidea have been collected from the gill chamber of the ichthyodectid fish Cladocyclus gardneri. The fossils provide conclusive evidence suporting recent theories that link caligid copepods, which are parasitic on fish, to the invertebrate-associated siphonostomes. This is the first discovery of fossil parasitic copepods, and they are by far the oldest copepods of any sort known.