Cancer mortality patterns in selected Northern and Southern African countries

BACKGROUND

Non-communicable diseases have been rapidly increasing in African countries. We provided updated cancer death patterns in selected African countries over the last two decades.

METHODS

We extracted official death certifications and population data from the WHO and the United Nations Population Division databases. We computed country- and sex-specific age-standardized mortality rates per 100 000 person-years for all cancers combined and ten major cancer sites for the periods 2005-2007 and 2015-2017.

RESULTS

Lung cancer ranked first for male cancer mortality in all selected countries in the last available period (with the highest rates in Réunion 24/100 000), except for South Africa where prostate cancer was the leading cause of death (23/100 000). Prostate cancer ranked second in Morocco and Tunisia and third in Mauritius and Réunion. Among Egyptian men, leukemia ranked second (with a stable rate of 4.2/100 000) and bladder cancer third (3.5/100 000). Among women, the leading cancer-related cause of death was breast cancer in all selected countries (with the highest rates in Mauritius 19.6/100 000 in 2015-2017), except for South Africa where uterus cancer ranked first (17/100 000). In the second rank there were colorectal cancer in Tunisia (2/100 000), Réunion (9/100 000) and Mauritius (8/100 000), and leukemia in Egypt (3.2/100 000). Colorectal and pancreas cancer mortality rates increased, while stomach cancer mortality rates declined.

CONCLUSION

Certified cancer mortality rates are low on a global scale. However, mortality rates from selected screening detectable cancers, as well as from infection-related cancers, are comparatively high, calling for improvements in prevention strategies.

Cancer mortality associated with low education in Italy

BACKGROUND

This study provides a nationwide representative quantification of the impact of educational inequalities on cancer mortality in Italy.

METHODS

The study is based on prevalence data and mortality rate ratios according to levels of education obtained from the Italian 2011 census cohort, including >35 million individuals aged 30-74. We estimated the population attributable fraction (PAF) and the number of cancer deaths associated with low education (below university degree) in Italy by sex.

RESULTS

PAFs for low levels of education were 29.1% among men and 13.3% among women, corresponding to 22,271 cancer deaths associated with low education in men and 7456 in women in 2019. PAFs by cancer site in men were: 53.0% for upper aerodigestive tract (UADT), 44.6% for liver, 41.3% for stomach, 41.3% for lung, 37.0% for bladder, 18.5% for colorectal, 9.8% for prostate and 9.1% for pancreatic cancers. PAFs in women were: 44.5% for cervical, 36.1% for UADT, 34.9% for stomach and 13.9% for colorectal cancers. The cancer sites with the highest number of deaths associated with low education were lung among men (7902/22,271, 35.5%) and colorectum among women (780/7456, 10.5%).

CONCLUSIONS

About a quarter of cancer deaths in 2019 in Italy may be prevented by reducing the socioeconomic determinants that contribute to educational disparities in cancer mortality.

A comprehensive analysis of all-cause and cause-specific excess deaths in 30 countries during 2020

The impact of COVID-19 on mortality from specific causes of death remains poorly understood. This study analysed cause-of-death data provided by the World Health Organization from 2011 to 2019 to estimate excess deaths in 2020 in 30 countries. Over-dispersed Poisson regression models were used to estimate the number of deaths that would have been expected if the pandemic had not occurred, separately for men and women. The models included year and age categories to account for temporal trends and changes in size and age structure of the populations. Excess deaths were calculated by subtracting observed deaths from expected ones. Our analysis revealed significant excess deaths from ischemic heart diseases (IHD) (in 10 countries), cerebrovascular diseases (CVD) (in 10 countries), and diabetes (in 19 countries). The majority of countries experienced excess mortality greater than 10%, including Mexico (+ 38·8% for IHD, + 34·9% for diabetes), Guatemala (+ 30·0% for IHD, + 10·2% for CVD, + 39·7% for diabetes), Cuba (+ 18·8% for diabetes), Brazil (+ 12·9% for diabetes), the USA (+ 15·1% for diabetes), Slovenia (+ 33·8% for diabetes), Poland (+ 30·2% for IHD, + 19·5% for CVD, + 26 1% for diabetes), Estonia (+ 26·9% for CVD, + 34·7% for diabetes), Bulgaria (+ 22·8% for IHD, + 11·4% for diabetes), Spain (+ 19·7% for diabetes), Italy (+ 18·0% for diabetes), Lithuania (+ 17·6% for diabetes), Finland (+ 13·2% for diabetes) and Georgia (+ 10·7% for IHD, + 19·0% for diabetes). In 2020, 22 out of 30 countries had a significant increase in total mortality. Some of this excess was attributed to COVID-19, but a substantial increase was also observed in deaths attributed to cardiovascular diseases and diabetes.

Lung cancer mortality in the wake of the changing smoking epidemic: a descriptive study of the global burden in 2020 and 2040

OBJECTIVES

Lung cancer (LC) is the leading cause of cancer death in 2020, responsible for almost one in five (18.0%) deaths. This paper provides an overview of the descriptive epidemiology of LC based on national mortality estimates for 2020 from the International Agency for Research on Cancer (IARC), and in the context of recent tobacco control policies.

DESIGN AND SETTING

For this descriptive study, age-standardised mortality rates per 100 000 person-years of LC for 185 countries by sex were obtained from the GLOBOCAN 2020 database and stratified by Human Development Index (HDI). LC deaths were projected to 2040 based on demographic changes alongside scenarios of annually increasing, stable or decreasing rates from the baseline year of 2020.

RESULTS

LC mortality rates exhibited marked variations by geography and sex. Low HDI countries, many of them within sub-Saharan Africa, tend to have low levels of mortality and an upward trend in LC deaths is predicted for both sexes until 2040 according to demographic projections, irrespective of trends in rates. In very high HDI countries, including Europe, Northern America and Australia/New Zealand, there are broadly decreasing trends in men whereas in women, rates are still increasing or reaching a plateau.

CONCLUSION

The current and future burden of LC in a country or region largely depends on the present trajectory of the smoking epidemic in its constituent populations, with distinct gender differences in smoking patterns, both in transitioning and transitioned countries. Further elevations in LC mortality are expected worldwide, raising important social and political questions, especially in low-income and middle-income countries.

Mortality patterns of soft-tissue sarcomas worldwide up to 2018, with predictions for 2025

OBJECTIVE

The epidemiological evidence on soft-tissue sarcoma (STS) mortality is inconsistent in geographic and time coverage. This study provides mortality trends for STSs in selected countries worldwide over the last 2 decades, together with predicted figures for 2025.

METHODS

We extracted official numbers of certified deaths coded as C47 (i.e. malignant neoplasm of peripheral nerves and autonomic nervous system) and C49 (i.e. malignant neoplasm of other connective and soft tissue) according to the 10th Revision of the International Classification of Disease and population estimates from the WHO and the Pan American Health Organization databases. We computed age-standardized (world standard population) mortality rates (ASMRs). We used joinpoint regression analysis to identify significant changes in trends and to predict death numbers and rates for 2025.

RESULTS

The pattern emerging from the number of deaths and ASMRs up to 2018 shows an increase in most countries in both sexes. Around 2015 to 2018, ASMRs differed by 2.5-fold in both sexes with the highest rates being registered in Central-Eastern Europe, North America and Australia, while the lowest ones in Latin America, Japan, and Korea. In 2025, the number of STS deaths is predicted to increase in most countries and both sexes, and unfavourable rates are predicted in Central Europe in both sexes.

CONCLUSION

In addition to improvements in STSs registration, unfavourable mortality rates reported in this study reflect inadequate referral of patients with STSs to high-volume multidisciplinary centres, as well as insufficient advancements in STS prevention, diagnosis, and treatments.

Cancer mortality and predictions for 2022 in selected Australasian countries, Russia, and Ukraine with a focus on colorectal cancer

OBJECTIVE

We aimed at predicting cancer mortality rates for the current year for the Russian Federation, Ukraine, Israel, Hong Kong SAR, Japan, Korea, and Australia, with a focus on colorectal cancer.

METHODS

We retrieved official death certification and population data from the WHO and the United Nations Population Division databases. We analyzed mortality for all cancers combined and for 10 major cancer sites from 1970 to 2019, or the latest available year. We predicted numbers of deaths and age-standardized mortality rates for 2022 using Poisson joinpoint regression models. We estimated the number of averted deaths over the period 1994-2022 because of the decline in mortality rates.

RESULTS

Total cancer mortality declined in all countries and both sexes. Russia had the highest total cancer predicted rates for 2022: 156.4/100 000 (world standard) in men and 81.4 in women; the lowest rates were reported in Israeli men (90.6/100 000) and Korean women (44.5/100 000). Between 1994 and 2022, a total of 1 487 000 deaths were estimated to be avoided in Russia, 502 000 in Ukraine, 58 000 in Israel, 102 000 in Hong Kong SAR, 1 020 000 in Japan, 533 000 in the Republic of Korea, and 263 000 in Australia. Colorectal cancer mortality trends were downward for the last decades with favorable predictions for 2022 in both sexes.

CONCLUSION

In the countries considered, predicted downward trends started later and were less marked than those in the European Union and the USA. Despite overall favorable predictions, colorectal cancer remains one of the major causes of cancer mortality.

Mammographic breast density and survival in women with invasive breast cancer

PURPOSE

We explored the under-debate association between mammographic breast density (MBD) and survival.

METHODS

From the Piedmont Cancer Registry, we identified 693 invasive breast cancer (BC) cases. We analyzed the overall survival in strata of MBD through the Kaplan-Meier method. Using the Cox proportional hazards model, we estimated the hazard ratios (HRs) of death; using the cause-specific hazards regression model, we estimated the HRs of BC-related and other causes of death. Models included term for Breast Imaging-Reporting and Data System (BI-RADS) MBD (categorized as BI-RADS 1 and BI-RADS 2-4) and were adjusted for selected patient and tumour characteristics.

RESULTS

There were 102 deaths, of which 49 were from BC. After 5 years, the overall survival was 69% in BI-RADS 1 and 88% in BI-RADS 2-4 (p < 0.01). Compared to BI-RADS 2-4, the HRs of death for BI-RADS 1 were 1.65 (95% CI 1.06-2.58) in the crude model and 1.35 (95% CI 0.84-2.16) in the fully adjusted model. Compared to BI-RADS 2-4, the fully adjusted HRs for BI-RADS 1 were 1.52 (95% CI 0.74-3.13) for BC-related death and 1.83 (95% CI 0.84-4.00) for the other causes of death.

CONCLUSION

Higher MBD is one of the strongest independent risk factors for BC, but it seems not to have an unfavorable impact on survival.

Socioeconomic status and risk of lung cancer by histological subtype in the Nordic countries

BACKGROUND

While the excess in lung cancer risk among lower socioeconomic status individuals has been widely described, the magnitude of this association across lung cancer subtypes, as well as histotype-related long-term incidence trends, are inconclusively reported.

AIMS

We explored the variation in the incidence of the three main lung cancer histotypes (i.e. squamous cell carcinoma, small cell carcinoma and adenocarcinoma) by socioeconomic status (SES, i.e. upper and lower white collar, upper and lower blue collar, and farming/forestry/fishing) in the adult population of four Nordic countries (i.e. Sweden, Norway, Finland and Denmark).

MATERIALS & METHODS

We have used data from the Nordic Occupational Cancer Study (NOCCA), computing age-standardized incidence rates per 100,000 person-years truncated at ages 50-69 years, by sex, histotype, country and SES, for the period 1971-2005. We estimated relative risks and the corresponding 95% confidence intervals through Poisson regression models, including terms for SES, age, sex and country, as indicated.

RESULTS

A clear socioeconomic gradient, with a progressive increase in lung cancer risk as SES level decreases, was observed in all subtypes and in both sexes. Favourable lung cancer incidence trends were seen among men for squamous cell and small cell carcinomas, although for adenocarcinomas rates were increasing everywhere except for Finland. Among women, upward temporal trends were seen in all SES groups and for all subtypes, although rates increased to a greater extent for low, compared to high, SES, especially in Denmark and Norway. Farmers showed comparatively lower risks compared to other SES categories.

DISCUSSION

This prospective cohort study shows that substantial socioeconomic inequalities in the incidence of the most important lung cancer histotypes exist in the Nordic Countries, and that these inequalities are on the rise, especially among women.

CONCLUSION

Smoking habits are likely to largely explain the observed social gradient for lung cancer histotypes in both sexes.

The epidemiological landscape of thyroid cancer worldwide: GLOBOCAN estimates for incidence and mortality rates in 2020

BACKGROUND

Thyroid cancer incidence rates have increased in many countries and settings; however, mortality rates have remained stable at lower rates. This epidemiological pattern has been largely attributed to an overdiagnosis effect. Timely evidence for the global epidemiological status is necessary to identify the magnitude of this problem and the areas mostly affected by it. We therefore aimed to provide an up-to-date assessment on the global distribution of thyroid cancer incidence and mortality rates in 2020.

METHODS

We extracted age-standardised incidence and mortality rates per 100 000 person-years of thyroid cancer as defined by the International Classification of Diseases for Oncology 10th Revision (code C73), for 185 countries or territories by sex and 18 age groups (ie, 0-4, 5-9, …, 80-84, and ≥85 years) from the GLOBOCAN database. Both incidence and mortality estimates were presented by country and aggregated across the 20 UN-defined world regions and according to the UN's four-tier Human Development Index (ie, low, medium, high, and very high) in 2020.

FINDINGS

Globally, in 2020, the age-standardised incidence rates of thyroid cancer were 10·1 per 100 000 women and 3·1 per 100 000 men, and age-standardised mortality rates were 0·5 per 100 000 women and 0·3 per 100 000 men. In both sexes, incidence rates were five times higher in high and very high Human Development Index countries than in low and medium Human Development Index countries, whereas mortality rates were relatively similar across different settings. Incidence rates in women differed by more than 15 times across world regions, with the highest incidence rates being in the Federated States of Micronesia and French Polynesia (18·5 per 100 000 women), North America (18·4 per 100 000), and east Asia (17·8 per 100 000, with South Korea reaching 45 per 100 000). Mortality rates were less than one per 100 000 in most countries and in both sexes. South Korea had the highest incidence-to-mortality rate ratio in both sexes, followed by Cyprus and Canada.

INTERPRETATION

The current thyroid cancer epidemiological landscape is strongly suggestive of a large effect of overdiagnosis in many countries and settings worldwide, confirming the relevance of thyroid cancer overdiagnosis as a global public health problem.

FUNDING

None.

Trends in male breast cancer mortality: a global overview

OBJECTIVES

Recent trends in male breast cancer have been inadequately studied. We updated mortality trends in selected countries and regions worldwide using most recent available data and we predicted figures for 2020.

METHODS

We extracted official death certification data for male breast cancer and population estimates from the WHO and the Pan American Health Organization databases, from 2000 to 2017. We computed age-standardized (world population) death rates for selected countries and regions worldwide. We used joinpoint regression analysis to identify significant changes in trends and to predict death numbers and rates for 2020.

RESULTS

In 2015-2017, Central-Eastern Europe had a rate of 2.85/1 000 000, and Russia of 2.22, ranking among the highest. North-Western and Southern Europe, the European Union as a whole and the USA showed rates ranging between 1.5 and 2.0. Lower rates were observed in most Latin American countries, with values below 1.35/1 000 000, in Australia, 1.22, and Japan, 0.58. Between 2000-2004 and 2015-2017, age-adjusted death rates decreased between 10 and 40% in North-Western Europe, Russia, and the USA, and between 1.5 and 25% in the other areas under study, except Latin America (+0.8%). Except for Central-Eastern Europe, predicted rates for 2020 were favourable.

CONCLUSION

Advancements in management are likely the main drivers of the favourable trends in male breast cancer death rates over the last decades. Delayed diagnosis and limited access to effective care explain the higher mortality in some areas.

Cigarettes smoking and androgen receptor-positive breast cancer

OBJECTIVES

Cigarette smoking is related to higher levels of circulating androgens, but its association with androgen receptor (AR) status is still unaddressed.

METHODS

We analysed, with a case-only approach, smoking habits according to AR status in 112 cases of invasive female breast cancer, from the Piedmont Cancer Registry. We used a multivariate logistic regression model to estimate the odds ratio (OR) and the corresponding confidence interval (CI).

RESULTS

The OR of AR-positive breast cancer (versus AR-negative) for ever smokers (versus never) was 2.85 (95% CI 1.02-7.96).

CONCLUSION

Smoking is related to AR-positive breast cancer.

Cancer mortality and predictions for 2020 in selected Australasian countries, Russia and Ukraine

OBJECTIVES

Predicted cancer mortality figures are useful for public health planning. We predicted cancer mortality rates in Israel, Hong Kong, Japan, the Philippines, Korea, Australia, Russia and Ukraine for the year 2020 using the most recent available data. We focused on breast cancer.

METHODS

We obtained cancer death certification and population data from the WHO and the United Nations Population Division databases. We derived figures for 10 major cancer sites and total cancers over 1970-2017. We predicted numbers of deaths and age-standardized mortality rates for 2020 through joinpoint regression models. We calculated the number of avoided deaths from 1994-2020.

RESULTS

Overall, total cancer mortality is predicted to decline. Russia had the highest all cancers rates in 2020, 151.9/100 000 men and 79.6 women; the Philippines had the lowest rate in men, 78.0/100 000, Korea in women, 47.5. Stomach cancer rates declined over the whole period in all countries considered, colorectal cancer since the late 1990s. Trends for pancreas were inconsistent. Predicted rates for lung and breast cancer were favourable; women from Hong Kong, Korea and Australia had lung cancer death rates higher than breast ones. Predicted rates for uterine, ovarian, prostate and bladder cancers and leukaemias were downward for most countries. Between 1994 and 2020, over 3.3 million cancer deaths were avoided in the considered countries, except for the Philippines where no reduction was observed.

CONCLUSION

Predicted cancer rates were lower than in the European Union and the USA, even though falls started later and were less marked.

Mammographic breast density and characteristics of invasive breast cancer

INTRODUCTION

Inconclusive data exist on the association between breast density and breast cancer characteristics.

MATERIALS AND METHODS

We conducted a case-only study on 667 invasive breast cancers, using data from the Piedmont Cancer Registry. We applied a multivariate logistic regression model to estimate odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) of high breast density (Breast Imaging Reporting and Data System, BI-RADS 3-4) versus low (BI-RADS 1-2) in relation to histologic grade, pathological tumour size and lymph node status, histotype, estrogen and progesterone receptor, HER2 and Ki67 status. Histopathological data were assessed according to the American Joint Committee on Cancer (AJCC) Staging Manual guidelines. The model includes terms for age at diagnosis, education level, body mass index, reproductive factors, family history of breast cancer, smoking and diabetes.

RESULTS

As regards histologic grade, compared to well differentiated tumours, the OR of high (versus low) breast density cases was 0.61 (95% CI 0.38-0.98) for moderately-poorly differentiated tumours. No other associations with hormonal and histopathological characteristics were observed.

DISCUSSION

Our results indicate that low breast density is associated with moderately-poorly differentiated breast tumours.

The impact of selected risk factors among breast cancer molecular subtypes: a case-only study

PURPOSE

Breast cancer (BC) risk factors have been differentially associated with BC subtypes, but quantification is still undefined. Therefore, we compared selected risk factors with BC subtypes, using a case-case approach.

METHODS

We retrieved 1321 invasive female BCs from the Piedmont Cancer Registry. Through record linkage of clinical records, we obtained data on estrogen (Er) and progesterone (Pr) receptors, Ki67 and HER2+ status, BC family history, breast imaging reporting and data system (BI-RADS) density, reproductive risk factors and education. We defined BC subtypes as follows : luminal A (Er+ and/or Pr+ , HER2- , low Ki67), luminal BH- (Er+ and/or Pr + , HER2- , Ki67 high), luminal BH+ (Er+ and/or Pr + , HER2+), HER2+ (Er - , Pr - , HER2+), ) and triple negative (Er - , Pr - , HER2-). Using a multinomial regression model, we estimated the odds ratios (ORs) for selected BC risk factors considering luminal A as reference.

RESULTS

For triple negative, the OR for BC family history was 1.83 (95% confidence interval (CI) 1.13-2.97). Compared to BI-RADS 1, for triple negative, the OR for BI-RADS 2 was 0.56 (95% CI 0.27-1.14) and for BI-RADS 3-4 was 0.37 (95% CI 0.15-0.88); for luminal BH +, the OR for BI-RADS 2 was 2.36 (95% CI 1.08-5.11). For triple negative, the OR for high education was 1.78 (95% CI 1.03-3.07), and for late menarche, the OR was 1.69 (95% CI 1.02-2.81). For luminal BH + , the OR for parous women was 0.56 (95% CI 0.34-0.92).

CONCLUSIONS

This study supported BC etiologic heterogeneity across subtypes, particularly for triple negative.

Exploring the link between diabetes and pancreatic cancer

Introduction: Epidemiological studies indicate an association between type 2 diabetes and pancreatic cancer but the complex and multidirectional relationship between them remains unclear. Areas covered: We summarized epidemiological evidence on diabetes and pancreatic cancer exploring the time-risk relationship. We described mechanisms linking long-standing diabetes to pancreatic cancer. We discussed pancreatic cancer-associated diabetes and its implication in the early detection of pancreatic cancer. Expert opinion: The markedly increased risk of pancreatic cancer in patients with new-onset diabetes compared with long-standing diabetes observed in several epidemiological studies indicates a complex and bidirectional connection, with long-standing diabetes being a predisposing factor for pancreatic cancer (increasing the risk of the malignancy 1.5- to 2-fold) and new-onset diabetes an early manifestation of the tumor. Identifying clinical features and biomarkers to distinguish pancreatic cancer-associated diabetes from type 2 diabetes is an important goal to improve management and survival of this cancer. Imaging (MRI) for middle-age patients with new-onset diabetes may be considered.

Mechanical activation of Efavirenz: the effects on the dissolution and inhibitory behavior

A poorly water-soluble drug (Efavirenz) was mechanically activated by ball-milling. The effect of the mechanical activation on the dissolution behavior and bioavailability was investigated revealing possible correlations with the grinding action, in terms of crystallinity, particle size and morphology.With proper selection of the grinding parameters the dissolution kinetics can be controlled, both in terms of dissolution velocity and as amount of dissolved drug. In vitro biological tests show that milling does not impair the ability of Efavirenz to inhibit HIV-1 infection (p value >0.05); the IC50 values of ground Efavirenz is indeed lower than values for the pristine micronized powder.

Reversal of fetal ductal constriction after maternal restriction of polyphenol-rich foods: an open clinical trial

OBJECTIVE

To test the hypothesis that maternal restriction of polyphenol-rich foods (PRF), which, like non-steroidal anti-inflammatory drugs (NSAID), inhibit prostaglandin synthesis in the third trimester, reverse fetal ductal constriction (DC).

STUDY DESIGN

An open clinical trial of 51 third trimester fetuses with DC with no history of NSAID intake was designed. All mothers were submitted to a food frequency questionnaire and were oriented to withdrawl PRF, being reassessed after 3 weeks. Doppler parameters were assessed before and after discontinuation of these substances. A control group of 26 third trimester normal fetuses, with no ductus arteriosus (DA) constriction, in which no dietary intervention was offered, was reviewed after 3 weeks. Student's t-test and Wilcoxon's test were used.

RESULT

Mean gestational age was 32±3 weeks (28 to 37 weeks). After discontinuation of PRF (≥3 weeks), 48/51 fetuses (96%) showed complete reversal of DC, with decrease in mean ductal systolic velocity (1.74±0.20 m s(-1) to 1.31±0.34 m s(-1), P<0.001), mean diastolic velocity (0.33±0.09 m s(-1) to 0.21±0.07 m s(-1), P<0.001) and mean right to left ventricular dimension ratio (1.37±0.26 to 1.12±0.17, P<0.001) and increase in mean ductal pulsatility index (PI) (1.98±0.36 to 2.46±0.23, P<0.001). Median daily maternal consumption of PRF was 286 mg per day and decreased after orientation to 0 mg per day, P<0.001. In the control group, with GA of 32±4 w (29-37 w), there was no significant differences in median daily maternal consumption of PRF, mean ductal systolic velocitiy, diastolic velocity, PI and right ventricular to left ventricular diameter ratio (RV/LV) ratio.

CONCLUSION

Reduction of maternal PRF intake during pregnancy, especially in the third trimester, is followed by complete reversal of DC (wide open DA), which may influence maternal dietary habits in late pregnancy.

Insertion of targeting domains into the envelope glycoprotein of Moloney murine leukemia virus (MoMLV)-based vectors modulates the route of mCAT-1-mediated viral entry

Several groups have inserted targeting domains into the envelope glycoprotein (Env) of Moloney murine leukemia virus (MoMLV) in an attempt to produce targeted retroviral vectors for human gene therapy. While binding of these modified Envs to the target molecule expressed on the surface of human cells was observed, specific high-titer infection of human cells expressing the target molecule was not achieved. Here we investigate the initial steps in the entry process of targeted MoMLV vectors both in murine and human cells expressing the MoMLV receptor, the mouse cationic amino acid transporter-1 (mCAT-1). We show that insertion of a small ligand targeted to E-selectin and of a single chain antibody (scFv) targeted to folate-binding protein (FBP) into the N-terminus of MoMLV Env results in the reduction of the infectivity and the kinetics of entry of the MoMLV vectors. The use of soluble receptor-binding domain (sRBD), bafilomycin A1 (BafA1) and methyl-beta-cyclodextrin (MbetaC) increase the infectivity of the MoMLV vectors targeted to FBP (MoMLV-FBP) suggesting that the scFv targeted to FBP increases the threshold for fusion and might re-route entry of the targeted MoMLV-FBP vector towards an endocytic, non-productive pathway.

Evidence for nonspecific adsorption of targeted retrovirus vector particles to cells

The ability to specifically target a cell-type is important for the development of vectors for in vivo gene therapy. In order to produce retrovirus vectors targeting ovarian cancer cells, which specifically overexpress alpha folate receptor (alphaFR), a single chain antibody was fused as an N-terminal extension of the ecotropic and amphotropic murine leukemia virus (MLV) envelope glycoproteins. Vector particles bearing the modified glycoproteins were produced and analysed. Although conventional FACS studies indicated that viral particles bearing the modified Env could bind to ovarian cancer cells, targeted infection was not achieved. The initial step of virus-cell interaction was further studied using an immunofluorescence technique, which allows visualisation of single retrovirus particles. Vectors bearing chimeric or wild-type glycoproteins bound equally well to cells with or without the targeted receptor, although soluble chimeric glycoproteins bound specifically to FBP. Our results indicate that the incorporation of specific ligands to the virus envelope does not necessarily result in significant enhancement of vector particle binding. A similar interaction was also observed using Env-defective virus particles, suggesting that cellular factors incorporated into the lipid envelope play a dominant role in promoting initial adsorption of virus particles to cells. Significant implications arise from these observations on the interpretation of previous reports on 'targeted' vectors, and for the development of vectors for in vivo gene therapy protocols.

Development of a suspension packaging cell line for production of high titre, serum-resistant murine leukemia virus vectors

To date, only adherent cell lines have been used for the generation of packaging cells for the production of type C retrovirus vectors. The large-scale production of high titre retrovirus vectors could benefit from the development of packaging cells growing in suspension. Here, we describe the ability of two different lymphoid cell lines, one B- and one T-lymphoblastoid cell line (Namalwa and CEM, respectively), to produce MLV-based vectors. Upon transfection with a third generation packaging construct, the virus particle production by Namalwa cells was characterised by low RT-activity, and by CEM cells as high RT activity as previously established adherent packaging cells. An amphotropic packaging cell line (CEMFLYA) was therefore established from CEM cells. Upon introduction of a lacZ vector genome, the novel packaging cell line produced vector particles routinely in the region of 10(7) infectious units/ml. The vectors were helper-free and highly stable in fresh human serum. The potential for scaled up vector production was demonstrated by continuous culture of the new packaging cells for 14 days in a 250 ml spinner flask. These suspension packaging cells should be applicable to large bioreactor systems to bulk produce high titre, complement-resistant retrovirus vectors for gene therapy.

Progress with retroviral gene vectors

Retroviral vectors have become a standard tool for gene transfer technology. Compared with other gene transfer systems, retroviral vectors have several advantages, including their ability to transduce a variety of cell types, to integrate efficiently into the genomic DNA of the recipient cells and to express the transduced gene at high levels. The relatively well understood biology of retroviruses has made possible the development of packaging cell lines which provide in trans all the viral proteins required for viral particle formation. The design of different types of packaging cells has evolved to reduce the possibility of helper virus production. The host range of retroviruses has been expanded by pseudotyping the vectors with heterologous viral glycoproteins and receptor-specific ligands. The development of lentivirus vectors has allowed efficient gene transfer to quiescent cells. This review describes different strategies adopted for developing vectors to be used in gene therapy applications.

Gene Therapy of Glioblastoma Multiforme with a Bicistronic Retroviral Vector Expressing Human IL-2 and HSV-tK

Gene therapy of cancer includes strategies for augmentation of immunotherapeutic and chemoterapeutic approaches. These strategies mainly involve ex vivo and in vivo cytokine gene transfer, drug sensitization with genes for prodrug delivery, and the use of drug-resistance genes for protecting bone marrow from high-dose chemotherapy (1). Vector development remains the primary focus for any future research in the field. Retroviral vectors, especially those derived from Moloney murine leukemia virus (MoMLV), remain among the most widely utilized vectors in gene therapy trials.

Initial binding of murine leukemia virus particles to cells does not require specific Env-receptor interaction

The initial step of virus-cell interaction was studied by immunofluorescence microscopy. Single particles of murine leukemia virus (MLV) vectors and human immunodeficiency virus (HIV) were visualized by immunofluorescence. Fluorescent dots representing single virions could be localized by staining of capsid proteins (CA) or surface envelope proteins (SU) after fixation of virus supernatants. This technique can be used to determine particle concentration in viral supernatants and also to study virus-cell interaction. We investigated the role of the Env-receptor interaction for the initial binding event between the cell and the viral particles. Ecotropic MLV vector particles were shown to bind to human cells which do not express the specific viral receptor. In addition, MLV particles defective for Env were shown to bind the cells similarly to infectious MLV. Time course experiments of virus-cell binding and dissociation showed identical profiles for infectious and Env-defective MLV particles and suggested that MLV Env is not involved in the early phases of attachment of virus to cells. The possible implication of cellular factors in enhancing viral binding and infectivity is discussed.

Herpes simplex virus chronically infected human T lymphocytes are susceptible to HIV-1 superinfection and support HIV-1 pseudotyping

Peripheral blood lymphocytes (PBL) and CEM CD4+ T-cell line can be infected by herpes simplex virus-1 (HSV-1). CEM cells were characterized as a cellular model to study interactions occurring between HSV-1 and HIV-1. Virtually all cells were persistently infected by HSV-1 (CEM(HSV)) and expressed the latency associated transcripts, whereas only a fraction tested positive for HSV-antigens. CD4 and CXCR-4 expression and function were not affected in CEM(HSV) cells and no significant increase of deoxyribonucleotide pools was noticed. Superinfection of CEM(HSV) cells with HIV-1 led to a cell line chronically infected by both viruses (CEM(HSV/HSV)). Evidence was also obtained that this cell line can produce HIV-1 pseudotyped by HSV-1 envelope. These results may have important implications for a better understanding of AIDS pathogenesis.

Gene therapy of glioblastoma multiforme via combined expression of suicide and cytokine genes: a pilot study in humans

Retrovirus-mediated gene therapy is a particularly attractive approach for glioblastoma multiforme (GBM), given the poor prognosis of this tumour and its localized proliferation in post-mitotic tissue. In this study we assessed, for the first time in humans, the therapeutic potential of a newly designed bicistronic Moloney vector (pLIL-2-TK), combining the expression of a suicide gene (thymidine kinase, tk) with an immunomodulatory gene (human interleukin 2, IL-2). Evidence of transgene activity in the treated tumours is presented.

Production and characterization of a bicistronic Moloney-based retroviral vector expressing human interleukin 2 and herpes simplex virus thymidine kinase for gene therapy of cancer

Gene-based therapeutic strategies for cancer mainly include augmentation of immunotherapeutic and chemotherapeutic approaches. In this study we report the design and functional assay of a novel bicistronic Moloney-based retroviral vector expressing human interleukin-2 (IL-2) and herpesvirus thymidine kinase (tk) through a cap-dependent translation and an internal ribosome entry site (IRES)-regulated translation, respectively. This construct has the potential for allowing combination of cytokine and suicide gene therapy, especially in areas such as the brain, composed of post-mitotic cells refractory to transduction by type C retroviral vectors. Accordingly, human glioma cells were used as targets for gene transfer after selecting a packaging cell clone that produced a reasonable titer of recombinant virus and expressed high levels of IL-2 and tk transcripts. Although transduction efficiency was reduced in glioma cells as compared with murine NIH 3T3 cells, transgene expression was effectively achieved. Transduced glioma cells were sensitive to ganciclovir and secreted around 1000 U/ml IL-2 in the culture supernatants. Simultaneous production of IL-2 and tk in vivo by genetically treated tumor cells would hopefully potentiate the effect of gangiclovir-induced metabolic suicide, possibly by boosting the immune response associated with tumor debulking or by amplifying the bystander response.

Determination of HPRT mutant frequency and molecular analysis of T-lymphocyte mutants derived from coke-oven workers

We measured the frequency of mutant (MF) lymphocytes at the hprt locus in a population of 43 coke-oven workers exposed to PAH and in a group of 26 non-exposed workers. A non-significant increase in MF in the exposed group (19.0 +/- 16.3) compared to the non-exposed group (15.8 +/- 14.6) was observed. Moreover, when we considered smoking habits for the overall population, the MF values were higher, although not significantly, in smokers than in non-smokers. For some T-cell mutant clone structural alterations, splicing and coding errors were detected by PCR-based methods. We analysed 161 HPRT- clones, derived from exposed and non-exposed workers by multiplex-PCR and 56 HPRT- clones by reverse transcriptase-PCR. Overall, the percentages of the different types of gene alterations were similar in exposed and non-exposed subjects. Only the frequency of splice mutations in mutant clones derived from coke-oven workers was higher (22%) than in non-exposed donors (11%).

[Statistical results of 700 electrophysiologic tests (ERG) in patients without ophthalmologic manifestations treated with synthetic antimalarials for rheumatologic or dermatologic disease]

737 adapto-electroretinograms are registered on patients treated by chloroquine for a rheumatoid arthritis (RA) or for a lupus. Their ophthalmological examinations are completely normal. In term of the cumulative doses, the statistical results of the electrological characteristics of the different waves of the ERG issued from white, red and blue stimulations show: a great stability of the latencies of the "a" and "b" waves; a gradual decrease of the "b" wave amplitudes for the RA; a gradual increase of the "b" wave amplitudes till a level dose reached between 800 and 900 g and then a decrease of the "b" wave amplitudes, for the lupus. We discuss the electrophysiological criterions for a beginning intoxication. As a standard, for the R.A., it seems that a certain amount of "b" wave amplitude decrease could be admitted but the "a" and "b" wave latencies must be very constant. For the lupus, the hyper normality or at least stability of the "b" wave amplitude can be admitted till a dose around 800 g, associated to a good stability of the "a" and "b" wave latencies. Beyond these statistically established limits a beginning intoxication should be suspected.

[Retinal protection using glasses filtering short wave lengths in patients with hereditary degenerative diseases. First electrophysiologic results]

The electrophysiological action of the ORMA RT glasses filtering the short and middle wavelengths are exposed through the first results of this work by retinitis pigmentosa patients. In 90% of the tested patients A.E.R.G. and V.E.P. are improved.

Correlation functions in the analysis of visual evoked potentials

Our "vision" laboratory has been working for several years on stimulation methods and data processing. We present here the results of an analysis of correlation functions between VEPs obtained by flashes and patterned stimulations. This study provides additional information about possible interpretations.