The descriptive epidemiology of melanoma in Italy has changed - for the better

A recent research project using data from a total of 40 cancer registries has provided new epidemiologic insights into the results of efforts for melanoma control in Italy between the 1990s and the last decade. In this article, the authors present a summary and a commentary of their findings. Incidence increased significantly throughout the study period in both sexes. However, the rates showed a stabilization or a decrease in men and women aged below 35 years. The risk of disease increased for successive cohorts born until 1973 (women) and 1975 (men) while subsequently tending to decline. The trend towards decreasing tumor thickness and increasing survival has continued, but a novel favorable prognostic factor has emerged since 2013 for patients - particularly for males - with thick melanoma, most likely represented by molecular targeted therapies and immune checkpoint inhibitors. Due to this, the survival gap between males and females has been filled out. In the meanwhile, and despite the incidence increase, dermatologists have not lowered their threshold to perform skin biopsy. Skin biopsy rate has increased because of the increasingly greater volume of dermatologic office visits, but the proportion of skin biopsies out of dermatologic office visits has remained constant. In summary, an important breakthrough in melanoma control in Italy has taken place. Effective interventions have been implemented across the full scope of care, which involve many large local populations - virtually the whole national population. The strategies adopted during the last three decades represent a valuable basis for further steps ahead in melanoma control in Italy.

Cancer and Pregnancy: Estimates in Italy from Record-Linkage Procedures between Cancer Registries and the Hospital Discharge Database

The aim of this study is to describe the frequency and trend of pregnancy-associated cancer (PAC) in Italy, an increasingly relevant phenomenon due to postponing age at childbirth. To this purpose, a population-based retrospective longitudinal study design based on cohorts of women aged 15-49 diagnosed with cancer and concomitant pregnancy is proposed. The study uses 19 population-based Cancer Registries, covering about 22% of Italy, and linked at an individual level with Hospital Discharge Records. A total of 2,861,437 pregnancies and 3559 PAC are identified from 74,165 women of the cohort with a rate of 1.24 PAC per 1000 pregnancies. The most frequent cancer site is breast (24.3%), followed by thyroid (23.9%) and melanoma (14.3%). The most frequent outcome is delivery (53.1%), followed by voluntary termination of pregnancy and spontaneous abortion (both 12.0%). The trend of PAC increased from 2003 to 2015, especially when the outcome is delivery, thus confirming a new attitude of clinicians to manage cancer throughout pregnancy. This represents the first attempt in Italy to describe PAC from Cancer Registries data; the methodology is applicable to other areas with the same data availability. Evidence from this study is addressed to clinicians for improving clinical management of women with PAC.

Patient presentation, skin biopsy utilization and cutaneous malignant melanoma incidence and mortality in northern Italy: Trends and correlations

BACKGROUND

The global increase in incidence of cutaneous malignant melanoma (CMM) occurring in the past decades has been partly attributed to increased diagnostic scrutiny of early lesions, with a potential phenomenon of overdiagnosis. The reported positive linear relation between skin biopsy rate and incidence of early CMM is compatible with this hypothesis.

OBJECTIVES

We explored the ecological association between the trends in annual dermatologic office visit rates, skin biopsy rates, incidence rates of in situ and invasive CMM by tumour thickness category, and CMM mortality rates in the Emilia-Romagna Region (northern Italy).

METHODS

Four cancer registries covering a population of 2,696,000 provided CMM incidence data for the years 2003-2017. Dermatologic office visit rates and skin biopsy rates were calculated using the Regional outpatient care database. All rates were age-standardized. Trends were described with the estimated average annual per cent change (EAAPC). Correlations were tested with the Spearman correlation coefficient.

RESULTS

Incidence increased significantly. The increase was steeper for in situ CMM (EAAPC: men, 10.2; women, 6.9) followed by CMM <0.8 mm thick (9.1; 5.2), but the rates grew significantly for most subgroups of CMMs ≥0.8 mm thick. Mortality decreased significantly among women (-2.3) and non-significantly among men. For dermatologic office visit rate and skin biopsy rate the EAAPC were, respectively, 1.7 and 1.8 for men and 1.2 and 0.9 for women. Annual dermatologic office visit rate correlated with skin biopsy rate in both sexes. However, the proportion of skin biopsies out of dermatologic office visits was constant across the years (range: men, 0.182-0.216; women, 0.157-0.191).

CONCLUSIONS

In Italy, the increasing CMM incidence trend is, at least in part, genuine. Overdiagnosis-if any-is due to an increased patient presentation at dermatologic offices and not to a lower dermatologic threshold to perform biopsy.

The relative contribution of the decreasing trend in tumour thickness to the 2010s increase in net survival from cutaneous malignant melanoma in Italy: a population-based investigation

BACKGROUND

The long-term increase in survival from cutaneous malignant melanoma (CMM) is generally attributed to the decreasing trend in tumour thickness, the single most important prognostic factor.

OBJECTIVES

To determine the relative contribution of decreased tumour thickness to the favourable trend in survival from CMM in Italy.

METHODS

Eleven local cancer registries covering a population of 8 056 608 (13.4% of the Italian population in 2010) provided records for people with primary CMM registered between 2003 and 2017. Age-standardized 5-year net survival was calculated. Multivariate analysis of 5-year net survival was undertaken by calculating the relative excess risk (RER) of death. The relative contribution of the decrease in tumour thickness to the RER of death was evaluated using a forward stepwise flexible parametric survival model including the available prognostic factors.

RESULTS

Over the study period, tumour thickness was inversely associated with 5-year net survival and multivariate RER in both sexes. The median thickness was 0.90 mm in 2003-2007, 0.85 mm in 2008-2012 and 0.75 mm in 2013-2017 among male patients, and 0.78 mm, 0.77 mm and 0.68 mm among female patients, respectively. The 5-year net survival was 86.8%, 89.2% and 93.2% in male patients, and 91.4%, 92.0% and 93.4% in female patients, respectively. In 2013-2017, male patients exhibited the same survival as female patients despite having thicker lesions. For them, the increasing survival trend was more pronounced with increasing thickness, and the inclusion of thickness in the forward stepwise model made the RER in 2013-2017 vs. 2003-2007 increase from 0.64 [95% confidence interval (CI) 0.51-0.80] to 0.70 (95% CI 0.57-0.86). This indicates that the thickness trend accounted for less than 20% of the survival increase. For female patients, the results were not significant but, with multiple imputation of missing thickness values, the RER rose from 0.74 (95% CI 0.58-0.93) to 0.82 (95% CI 0.66-1.02) in 2013-2017.

CONCLUSIONS

For male patients in particular, decrease in tumour thickness accounted for a small part of the improvement in survival observed in 2013-2017. The introduction of targeted therapies and immune checkpoint inhibitors in 2013 is most likely to account for the remaining improvement.

Risk of thyroid as a first or second primary cancer. A population-based study in Italy, 1998-2012

BACKGROUND

The number of patients living after a cancer diagnosis is increasing, especially after thyroid cancer (TC). This study aims at evaluating both the risk of a second primary cancer (SPC) in TC patients and the risk of TC as a SPC.

METHODS

We analyzed two population-based cohorts of individuals with TC or other neoplasms diagnosed between 1998 and 2012, in 28 Italian areas covered by population-based cancer registries. Standardized incidence ratios (SIRs) of SPC were stratified by sex, age, and time since first cancer.

RESULTS

A total of 38,535 TC patients and 1,329,624 patients with other primary cancers were included. The overall SIR was 1.16 (95% CI: 1.12-1.21) for SPC in TC patients, though no increase was shown for people with follicular (1.06) and medullary (0.95) TC. SPC with significantly increased SIRs was bone/soft tissue (2.0), breast (1.2), prostate (1.4), kidney (2.2), and hemolymphopoietic (1.4) cancers. The overall SIR for TC as a SPC was 1.49 (95% CI: 1.42-1.55), similar for all TC subtypes, and it was significantly increased for people diagnosed with head and neck (2.1), colon-rectum (1.4), lung (1.8), melanoma (2.0), bone/soft tissue (2.8), breast (1.3), corpus uteri (1.4), prostate (1.5), kidney (3.2), central nervous system (2.3), and hemolymphopoietic (1.8) cancers.

CONCLUSIONS

The increased risk of TC after many other neoplasms and of few SPC after TC questions the best way to follow-up cancer patients, avoiding overdiagnosis and overtreatment for TC and, possibly, for other malignancies.

Excess risk of subsequent malignant neoplasms in adolescent and young adult cancer survivors: Results from the first Italian population-based cohort

BACKGROUND

Evidence about late effects in adolescent and young adult (AYA) cancer survivors is scarce. This study assessed the risk of subsequent malignant neoplasms (SMNs) to identify the most common SMNs to be considered in follow-up care.

METHODS

Population-based cancer registries retrospectively identified first primary tumors (between 1976 and 2013) and SMNs in AYAs (15-39 years old at their cancer diagnosis). AYA cancer survivors were those alive at least 5 years after their first cancer diagnosis. The excess risk of SMNs was measured as standardized incidence ratios (SIRs) and absolute excess risk together with the cumulative incidence of SMNs.

RESULTS

The cohort included 67,692 AYA cancer survivors. The excess risk of developing any SMN (SIR, 1.6; 95% confidence interval, 1.5-1.7) was 60%. The excess risk of SMNs was significantly high for survivors of lymphomas; cancers of the breast, thyroid, female genital tract, digestive organs, gonads, and urinary tract; and melanomas. The cumulative incidence of all SMNs in AYA cancer survivors within 25 years of their first cancer diagnosis was approximately 10%. Subsequent tumors contributing to approximately 60% of all SMNs were breast cancer, colorectal cancer, corpus uteri cancer, and ovarian cancer in females and colorectal cancer, bladder cancer, prostate cancer, lung cancer, and lymphomas in males.

CONCLUSIONS

These results highlight the need to personalize follow-up strategies for AYA cancer survivors.

Patterns of care and cost profiles of women with breast cancer in Italy: EPICOST study based on real world data

OBJECTIVES

To estimate total direct health care costs associated to diagnosis and treatment of women with breast cancer in Italy, and to investigate their distribution by service type according to the disease pathway and patient characteristics.

METHODS

Data on patients provided by population-based Cancer Registries are linked at individual level with data on health-care services and corresponding claims from administrative databases. A combination of cross-sectional approach and a threephase of care decomposition model with initial, continuing and final phases-of-care defined according to time occurred since diagnosis and disease outcome is adopted. Direct estimation of cancer-related costs is obtained.

RESULTS

Study cohort included 49,272 patients, 15.2% were in the initial phase absorbing 42% of resources, 79.7% in the continuing phase absorbing 44% of resources and 5.1% in the final phase absorbing 14% of resources. Hospitalization was the most important cost driver, accounting for over 55% of the total costs.

CONCLUSIONS

This paper represents the first attempt in Italy to estimate the economic burden of cancer at population level taking into account the entire disease pathway and using multiple current health care databases. The evidence produced by the study can be used to better plan resources allocation. The model proposed is replicable to countries with individual health care information on services and claims.

Diabetes: awareness and management. Data of Passi and Passi d’Argento surveillance in Lazio, Italy

Background

Diabetes is a health emergency: in Italy over 3 million people are diabetics. In Lazio region a high percentage of population is affected by diabetes. Data are collected from two Italian population surveillance systems, Passi during 2015-18 and Passi d'Argento (PdA) during 2016-2018; this trasversal study was conducted to investigate diabetes awareness and clinical management in Lazio.

Methods

Passi and PdA collect representative data providing a telephone interview with a standardized questionnaire to a representing sample (18-69 and over 65 aged respectively), randomly selected and sex-and-age stratified. In both questionnaires a diabetes section assesses diagnosis, knowledge of HbA1c, health setting and number of annual checks. Data refer to whom affirm to be diagnosed with diabetes. Results are shown by prevalence and 95% CI.

Results

Diabetes prevalence grows with age, it does not reach 1% in people under 50 years, it is 9% for the age group 50-69 years and 20% in over 75. Serious economic difficulties and low education level are related to higher prevalence. Among diabetics, 18.7% (15.42-22.46) from Passi and 24.2% (20.29- 28.61) from PdA ignore HbA1c. About clinical management, 1.5% (0.73-2.90) in Passi do not receive any care from doctor; the whole sample of PdA receives medical care. Most of the respondents in both surveillance are managed by diabetes care team (43.76% in Passi - 39.87% in PdA), reporting to receive care about three times a year on average. No significant differences are observed between economic and education levels.

Conclusions

High percentage of diabetics, not knowing HbA1c, are not aware about disease. Patient empowerment is necessary to gain control over disease and increases capacity to act on it. Health education should be improved and diagnostic and therapeutic pathways, recently introduced in Lazio Region, should be better structured. Population surveillances allow to plan and evaluate programs and interventions.

Key messages

Fight the lack of awareness with patient empowerment to gain control over diabetes. Population surveillances are valuable tools to plan and evaluate programs and interventions in Public Health.

Adolescent and Young Adult Cancer Survivors: Design and Characteristics of the First Nationwide Population-Based Cohort in Italy

Purpose: Adolescent and young adult (AYA, 15-39 years) cancer survivors (alive at least 5 years after cancer diagnosis) are less studied than younger and older cancer survivors and research on their late effects is limited. To facilitate research on long-term outcomes of AYA cancer survivors, we established, in Italy, a population-based AYA cancer survivors' cohort. This article describes the study design and main characteristics of this cohort. Methods: The cohort derives from population-based cancer registries (CRs). Each CR identified AYA cancer patients retrospectively. Treatment for first primary cancer and all health events from diagnosis to death can be traced through linkage with available health databases, such as hospital discharge records (HDRs), mortality files, and outpatient and pharmaceutical databases. Results: Thirty-four CRs participated to the cohort which overall includes 93,291 AYAs with cancer and 67,692 cancer survivors. First primary cancer distribution in AYA cancer survivors differs by sex and age groups because of the different cancer types diagnosed in AYAs. Almost 78% of AYA cancer survivors have HDRs and 14.8% also pharmaceutical and outpatient databases. Conclusion: This cohort will be used to study, for the first time in Italy, the pattern and excess risk of late effects in AYA cancer survivors. HDRs, outpatient and pharmaceutical databases will be used to define primary treatment to assess its impact on AYA cancer survivors' late effects. This cohort exploiting data sources already available at CRs, minimize the data collection effort and it will contribute to assess the feasibility of using administrative database to study cancer survivors' late effects.

Neoadjuvant therapy for breast cancer

Objective:

To evaluate the frequency of neoadjuvant therapy (NT) in women with stage I–III breast cancer in Italy and whether it is influenced by biological characteristics, screening history, and geographic area.

Methods:

Data from the High Resolution Study conducted in 7 Italian cancer registries were used; they are a representative sample of incident cancers in the study period (2009–2013). Included were 3546 women aged <85 years (groups <50, 50–69, 70–64, and 75+) with stage I–III breast cancer at diagnosis who underwent surgery. Women were classified as receiving NT if they received chemotherapy, target therapy, and/or hormone therapy before the first surgical treatment. Logistic models were built to test the association with biological and contextual variables.

Results:

Only 8.2% of women (290 cases) underwent NT; the treatment decreases with increasing age (14.5% in age <50 and 2.2% in age 75+), is more frequent in women with negative receptors (14.8%), HER2-positive (15.7%), and triple-negative (15.6%). The multivariable analysis showed the probability of receiving NT is higher in stage III (odds ratio [OR] 3.83; 95% confidence interval [CI] 2.83–5.18), luminal B (OR 1.87; 95% CI 1.27–2.76), triple-negatives (OR 1.88; 95% CI 1.15–3.08), and in symptomatic cancers (OR 1.98; 95% CI 1.13–3.48). Use of NT varied among geographic areas: Reggio Emilia had the highest rates (OR 2.29; 95% CI 1.37–3.82) while Palermo had the lowest (OR 0.41; 95% CI 0.24–0.68).

Conclusions:

The use of NT in Italy is limited and variable. There are no signs of greater use in hospitals with more advanced care.

Changes in life expectancy for cancer patients over time since diagnosis

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Research question: how cancer impacts on LE changes during patients’ entire life

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LE increased in patients surviving the first years and decreasing thereafter.

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Patients’ LE in the long-term approached but seldom reached the general population’s LE.

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This method describes when cancer survivors’ excess risk of death became negligible.

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Life expectancy indicator is easy to be understood and interpreted by patients.

The aims of this study were to provide life expectancy (LE) estimates of cancer patients at diagnosis and LE changes over time since diagnosis to describe the impact of cancer during patients' entire lives. Cancer patients' LE was calculated by standard period life table methodology using the relative survival of Italian patients diagnosed in population-based cancer registries in 1985–2011 with follow-up to 2013. Data were smoothed using a polynomial model and years of life lost (YLL) were calculated as the difference between patients' LE and that of the age- and sex-matched general population. The YLL at diagnosis was highest at the youngest age at diagnosis, steadily decreasing thereafter. For patients diagnosed at age 45 years, the YLL was above 20 for lung and ovarian cancers and below 6 for thyroid cancer in women and melanoma in men. LE progressively increased in patients surviving the first years, decreasing thereafter, to approach that of the general population. YLL in the long run mainly depends on attained age. Providing quantitative data is essential to better define clinical follow-up and plan health care resource allocation. These results help assess when the excess risk of death from tumour becomes negligible in cancer survivors.

Transmission in vitro of hepatitis C virus from persistently infected human B-cells to hepatoma cells by cell-to-cell contact

Virus cell-to-cell spread has been reported for many different viruses and may contribute to pathogenesis of viral disease. The role played by cell-to-cell contact in hepatitis C virus (HCV) transmission was studied in vitro by cell co-cultivation experiments. A human lymphoblastoid B-cell line, infected persistently with HCV in vitro (TO.FE(HCV)), was used as HCV donor [Serafino et al., 2003]; recipient cells were the human hepatoma HepG2 cell line. Both cell types were co-cultured for 48 hr to allow the cell-to-cell contacts. The hepatoma HepG2 cells are not permissive to free-virus infection, but they were infected successfully using TO.FE(HCV) cells as source of virus. The kinetics of viral RNA synthesis and the percentage of infected cells were compared in cell-mediated-and cell-free-viral infection. After co-cultivation, a consistent proportion of hepatoma cells replicated HCV and stably expressed viral antigens. Virus produced was infectious as demonstrated by the ability to reinfect fresh B-cells. This cell model shows that permissiveness to HCV infection can be achieved in vitro in non-permissive hepatoma cells by direct cell-to-cell contacts with infected human B-cells. This mechanism of virus spread may also play a pathogenic role in vivo.

Novel and recurrent mutations in the integrin beta 4 subunit gene causing lethal junctional epidermolysis bullosa with pyloric atresia

In this study we examined two unrelated patients affected with the lethal variant of junctional epidermolysis bullosa with pyloric atresia (PA-JEB) who were found to carry mutations in the integrin beta4 subunit gene (ITGB4). Although in both patients Northern blot analysis showed only a 50% reduction in the level of ITGB4 transcript, a complete lack (patient 1) or a strong reduction (patient 2) of beta4 immunoreactivity was observed in the skin. Using immunoprecipitation analysis, integrin beta4 could not be visualized in patient 1 cells while a markedly reduced amount (approximately 20%) of normal sized beta4 chains was detected in patient 2. These data suggested the presence of ITGB4 mutations that interfere with both mRNA and protein stability. Using molecular analysis, patient 1 was shown to be a compound heterozygous for a single amino acid deletion (deltaN318) and a not yet identified mutation that induces a very rapid decay of the encoded mRNA transcript. Patient 2 was, instead, a compound heterozygous for a novel 4-bp tandem duplication (4298-4299ins4) and a previously described missense mutation (R252C). Our data support the notion that PA-JEB lethal phenotypes associated with a markedly decreased/absent alpha6beta4 expression can be due not only to the presence of null alleles, but also to specific mutations leading to protein instability and/or altered function.

Low cell dosage of lymphoblastoid human cell lines EBV(+) is associated to chronic hepatitis in a minority of inoculated Nu/Nu mice

It has been suggested that an atypical course of primary infection by EBV and the reactivation of EBV infection in transplanted patients may induce hepatitis. We explored the possibility to dissect the infectious activity from the ability to promote B lymphocyte proliferation in vivo by injecting in nu/nu mice a low number (2 x 10(6)-0.05 x 10(6)) of cells from CE a normal human bone marrow-derived B cell line. This line carries an endogenous EBV in episomal and linear forms. Twenty nu/nu mice were inoculated subcutaneously with the B cell line CE and a matched group with the cell line RAG obtained by EBV in vitro infection of normal human peripheral blood. The mice injected with the CE line did not develop a lymphoproliferative disease, but 5 of them displayed typical histopathological lesions of chronic hepatitis without involvement of other organs. Similar results were obtained in 2 out of 20 animals in the RAG group. A close association between liver lesions and a previous EBV infection, by putative circulating B lymphoblastoid cells releasing their EBV, was established by PCR and by in situ hybridization with BamHI "W" DNA probe. This latter probe detected the presence of about 15% of positive cells only in affected livers. In addition, the rare detection in some hepatocytes of "A" type Cowdry bodies would suggest the occurrence of continuous EBV replication although at a very low level. These data show that we succeeded in dissecting the infectious from the proliferative activity of the endogenous EBV carrier CE cell line. This provides in addition a promising model for chronic EBV-associated hepatitis.

Molecular characterization and dynamics of hepatitis C virus replication in human fetal hepatocytes infected in vitro

The molecular features of hepatitis C virus (HCV) replication in human fetal hepatocytes (HFHs) were addressed in this study. Using a competitive reverse-transcription polymerase chain reaction (RT-PCR) assay for the quantitation of HCV-RNA molecules, the highest level of viral replication was detected 30 days' postinfection. At this time point, viral particles of 41 to 45 nm in diameter accumulated in the cell cytoplasm. Their density in cell extracts and culture medium was distributed between heavy (1.180-1.360 g/cm3) and light fractions (1.105-1.050 g/cm3) of a sucrose gradient, while, in the serum inoculum, they had a positive fraction at 1.180 g/cm3. In infected HFHs, minus-strand HCV RNA was observed in fractions displaying a sedimentation coefficient of 28 S to 18 S, while plus-strand HCV RNA showed a peak restricted to the 21 S fraction; the HCV RNA of serum inoculum had a sedimentation coefficient of 38 to 40 S, which revealed the presence of HCV RNA of unique positive polarity. The 21 S RNA fraction of cell extracts was resistant to 20 minutes of RNase I digestion, while the same incubation time totally inactivated a comparable amount of HCV RNA purified from the serum inoculum, revealing the presence of completely and/or partially double-stranded HCV-RNA molecules in the infected cells. Detection in HFHs of replicative forms and replicative intermediates suggests that the dynamic profile of HCV replication in these cells is similar to that described in other flaviviruses.

Quantitation of hepatitis C virus RNA production in two human bone marrow-derived B-cell lines infected in vitro

The ability of hepatitis C virus (HCV) to replicate in two B-cell lines, CE and TOFE, derived from bone marrow of healthy subjects was compared using qualitative and quantitative molecular methods. The presence of intracellular negative-stranded HCV RNA (replicative intermediate) was investigated by nested polymerase chain reaction (PCR) in the infected cultures at different times after infection. The amounts of positive-stranded HCV RNA (genomic RNA copies) synthesized and released from cells one week after in vitro infection were determined by competitive PCR after reverse transcription of viral RNA for the 5' viral untranslated region. In both cell lines, HCV RNA replication took place, but the TOFE cell line appeared to be a more efficient virus producer than the CE cell line. The TOFE cell line could be a valuable and reliable tool for basic and clinical HCV studies.

Detection of a 5' UTR variation in the HCV genome after a long-term in vitro infection

The TOFE lymphoid cell line from normal human bone marrow is susceptible to infection by a hepatitis C virus (HCV) serum strain. A sequence analysis of the 5' untranslated region (UTR) of HCV before and after long-term in vitro infection revealed one base substitution at position -158 (C > T) of the 5' UTR. We performed the direct sequencing of 5' UTR polymerase chain reaction-amplified sequences of the HCV genome: a) from the original serum-derived strain; b) from TOFE cell extracts 6 months post infection. This base substitution in the regulatory elements of the 5' UTR might be related to the ability of the virus to grow in cell culture.

Fusion of EBV with the surface of receptor-negative human hepatoma cell line Li7A permits virus penetration and infection

Our preliminary data suggest that Epstein-Barr virus (EBV) is able to bind to and fuse with the surface membranes of hepatoma cell line Li7A. In order to obtain further evidence, we utilized the relief of rhodamine fluorescence to monitor whether fusion would also take place when Li7A cells were exposed to experimental conditions such as neutral or low pH. It is well known that for some viruses, protonation in the endosomal compartment is needed to trigger the fusion. We show, furthermore, that the rate and extent of fusion are not affected by pretreatment of the cells with agents known to elevate the lysosomal and ensodomal pH, such as chloroquine or NH4Cl (lysosomotropic agent). By indirect immunofluorescence assay, in addition, we confirmed the binding of the EBV to the Li7A cell surface membrane. We attempted finally to correlate the above processes with successful infection of Li7A cells by EBV detected using the polymerase chain reaction technique. In spite of the apparent lack of viral receptor CD21, these nonlymphoid cells appeared susceptible to EBV penetration and infection through fusion with the plasma membrane at the surface of the cells.

Trans-activation of epidermal growth factor receptor gene by the hepatitis B virus X-gene product

The expression of the cellular gene coding for the epidermal growth factor (EGF) receptor (EGF-R) was assayed in the presence of hepatitis B virus (HBV) gene expression under different experimental conditions in human hepatoma-derived cells. First, transfection experiments of the well-differentiated HepG2 human hepatoma cell line using different expression vectors of the HBV X-region demonstrated that the X-gene product is capable of inducing EGF-R gene overexpression; in addition, by using a stable in vitro expression system for HBV, it was shown that EGF-R gene expression in these cells is greater than in the uninfected parent cells, and that this results in a three-fold increase in 125I-EGF binding. Finally, a CAT-expression assay was performed, indicating that regulatory regions of the EGF-R-gene are target sequences for X-protein trans-activation.

Replication and multiplication of hepatitis C virus genome in human foetal liver cells

The ability to obtain primary long-term cultures of human foetal hepatocytes maintaining liver differentiation characteristics in serum-free medium prompted us to test their susceptibility to hepatitis C virus infection. Using PCR, we detected the presence of the HCV RNA-positive strand in the supernatants and in the cells of the virus-infected hepatocyte cultures, at various times post-infection. Evidence of effective virus genome replication and multiplication was also based on the time-dependent appearance of the putative HCV RNA-negative strand, the detection of virus replicative intermediates and an increase in HCV genomic templates in the HCV-infected cells.

The human bone-marrow-derived B-cell line CE, susceptible to hepatitis C virus infection

The euploid-diploid cell line CE, issuing spontaneously from a normal human bone marrow culture, displays B-cell differentiation and activation markers and is positive (> or = 90% of cells) for Epstein-Barr nuclear antigens. CE suspensions were inoculated with serum from a patient chronically infected with hepatitis C virus (HCV). After inoculation, the cells were regularly subcultured with a split ratio of 1:2 every 4-6 days. RNA extracted as late as 65 days after infection from the inoculated cells were positive by polymerase chain reaction for the 5' untranslated region of the HCV genome, and viral antigens were detected by immunofluorescence. Virus was also released from the infected cells into the medium. Intracellular HCV could be successfully passaged twice in CE cultures. On the basis of these findings, the CE cell line appears promising as a model for studying HCV replication and persistent infection in vitro.

Early steps in fusion between Epstein-Barr virus and a human hepatoma cell line (Li7A)

Epstein-Barr virus, the causative agent of mononucleosis and several human cancers, infects cells via complement receptor type 2 (CR2). Expression of this receptor is restricted to B lymphocytes, some epithelial cells and immature thymocytes; expression of CR2-like proteins has been also found on T cells. In the present report, we identified the presence, on the membrane of Li7A cells, of a novel EBV receptor distinct from CR2 capable of triggering fusion with EBV virions with more rapid kinetics than that found with lymphoblastoid cells (Raji).

Susceptibility of human liver cell cultures to hepatitis C virus infection

To develop a cell culture system susceptible to infection by hepatitis C virus (HCV), human fetal hepatocytes, grown in serum-free medium, were inoculated with serum samples from two HCV-infected patients. Viral RNA sequences were detected by polymerase chain reaction, using primers specific for the 5' noncoding region of HCV, in extracts prepared from the hepatocyte cultures as early as 5 days after inoculation. Virus was also released from the infected cells into the medium. The HCV strains could be serially passaged three times into fresh liver cell cultures using intracellular virus as inoculum. Evidence that HCV replication really took place in primary human fetal hepatocytes was also obtained by detection of minus-strand viral RNA (replication intermediate) in cell extracts and of viral antigens in the infected cells.