Wastewater surveillance of SARS-CoV-2 variants in October-November 2022 in Italy: detection of XBB.1, BA.2.75 and rapid spread of the BQ.1 lineage.

This study adds insight regarding the occurrence and spread of SARS-CoV-2 Variants of Concern (VOCs) and Variants of Interest (VOIs) in Italy in October and November 2022, by testing urban wastewater collected throughout the country. A total of 332 wastewater samples were collected from 20 Italian Regions/Autonomous Provinces (APs) within the framework of national SARS-CoV-2 environmental surveillance. Of these, 164 were collected in the first week of October and 168 in the first week of November. A ∼1600 bp fragment of the spike protein was sequenced by Sanger (for individual samples) and long-read nanopore sequencing (for pooled Region/AP samples). In October, mutations characteristic of Omicron BA.4/BA.5 were detected in the vast majority (91 %) of the samples amplified by Sanger sequencing. A fraction of these sequences (9 %) also displayed the R346T mutation. Despite the low prevalence documented in clinical cases at the time of sampling, amino acid substitutions characteristic of sublineages BQ.1 or BQ.1.1 were detected in 5 % of sequenced samples from four Regions/APs. A significantly higher variability of sequences and variants was documented in November 2022, when the rate of sequences harbouring mutations of lineages BQ.1 and BQ1.1 increased to 43 %, and the number of Regions/APs positive for the new Omicron subvariant more than tripled (n = 13) compared to October. Moreover, an increase in the number of sequences with the mutation package BA.4/BA.5 + R346T (18 %), as well as the detection of variants never observed before in wastewater in Italy, such as BA.2.75 and XBB.1 (the latter in a Region where no clinical cases associated with this variant had ever been documented) was recorded. The results suggest that, as predicted by the ECDC, BQ.1/BQ.1.1 is rapidly becoming dominant in late 2022. Environmental surveillance proves to be a powerful tool for tracking the spread of SARS-CoV-2 variants/subvariants in the population.

C-reactive protein levels are associated with arterial media calcification in nondiabetic patients with end-stage renal disease on long-term hemodialysis.

BACKGROUND: Vascular calcifications (VC) are associated with cardiovascular (CV) morbidity and are independent predictors of CV mortality in end-stage renal disease (ESRD). This study aimed to investigate the presence of arterial intima calcification (AIC) and arterial media calcification (AMC) in nondiabetic patients on long-term hemodialysis, and to assess the association with CV risk factors. METHODS: 34 ESRD patients (17 males) on hemodialysis for at least 5 years were evaluated for VC using B-mode ultrasonography. RESULTS: AMC and AIC patterns were detected respectively in 62% and 59% of patients, and 21% had no VC. Patients with AIC were significantly older than those without AIC (p < 0.001). CRP levels (p < 0.001) were higher in patients with AMC. Using multivariate logistic analysis of regression, older age (> 50 years) and higher CRP levels (> 5 mg/l) were associated with AIC and AMC, respectively (p = 0.007 and p = 0.003). Logistic regression analysis showed that patients with CRP > 5 mg/l had a greater relative risk of having AMC (odds ratio 30, 95% confidence interval 27.041 - 32.959; p = 0.003). CONCLUSIONS: Ultrasonography can be used to detect AIC and AMC, and could be useful for the early detection of VC. In nondiabetic patients who had been on hemodialysis for at least 5 years, older age was associated with AIC, and elevated CRP levels with AMC.

Effect of melphalan and hyperthermia on cell cycle progression and cyclin B1 expression in human melanoma cells.

We have investigated the effect of mild hyperthermia (42 degrees C) on the cytotoxic activity of a 1 h melphalan exposure in human melanoma cell lines. Hyperthermia did not affect cell growth of any culture, but it increased, to a different extent, melphalan cytotoxicity in all cell lines, with a reduction in the IC50 of 1.7 to 2.6-fold. Flow cytometric analysis showed that in normal temperature conditions melphalan caused S phase cell accumulation, which was evident only at 24 h in JR8, M14 and 2/21 cell lines and was still persistent at 72 h in 2/60 cells. Moreover, in all cell lines, the delay in S phase was paralleled, or followed, by an accumulation of cells in G2+M, which was transient in JR8 and M14 cells and persisted until 72 h in 2/21 and 2/60 melanoma clones. Hyperthermia caused a stabilization and prolongation of melphalan induced G2+M accumulation in JR8 and M14 cells. Conversely, in 2/21 and 2/60 clones, cell cycle perturbations induced by the drug were similar under normothermic or hyperthermic conditions. Specifically, in JR8, for which the maximum enhancement by hyperthermia on melphalan cytotoxicity was observed, cell accumulation in G2+M was still present 120 h after treatment. The accumulation was accompanied by an inhibition in the G2-M transition, as demonstrated by the significant reduction in the mitotic index of cells exposed to combined treatment compared to controls. Moreover, a bivariate distribution of cells stained for DNA and cyclin B1 showed that, following melphalan and hyperthermia treatment, the fraction of cyclin B1-expressing cells paralleled the fraction of G2+M phase cells, thus indicating that the inability of cells to enter mitosis was not ascribable to a reduction of cyclin B1 expression. On the whole, our results indicate that hyperthermia can stabilize the G2 accumulation induced by melphalan in human melanoma cells. Such a stabilization could contribute to the enhancement of melphalan cytotoxicity by heat, even though a strict correlation was not observed between the magnitude and persistence of the cell cycle perturbations and the extent of melphalan activity.

Effects of a novel trinuclear platinum complex in cisplatin-sensitive and cisplatin-resistant human ovarian cancer cell lines: interference with cell cycle progression and induction of apoptosis.

We evaluated the effects of the trinuclear platinum complex, BBR 3464, in a human ovarian carcinoma cell line (OAW42) and in its cisplatin (CDDP)-resistant counterpart (OAW42MER). A 14-fold increased sensitivity to a 1-h BBR 3464 exposure was found in OAW42MER cells compared with their parental cell line. Flow cytometric experiments showed that BBR 3464 was able to induce a persistent block of OAW42 and OAW42MER cells in the G2M phase, whereas CDDP caused an initial accumulation of cells in the S phase followed by an increase in the G2M cell fraction in both cell lines. Exposure to equitoxic (IC(50)) drug concentrations induced programmed cell death in both cell lines. However, the percentage of cells with an apoptotic nuclear morphology was slightly higher after CDDP than BBR 3464 treatment in OAW42 cells, whereas the opposite pattern was observed in OAW42MER cells. Degradation of the nuclear lamin B was detected in OAW42 cells after exposure to each drug. Conversely, in OAW42MER cells lamin B cleavage was only appreciable after BBR 3464 exposure. In OAW42 cells, CDDP and BBR 3464 did not appreciably affect the mitochondrial membrane potential (Deltapsi(mt)), whereas in the OAW42MER cell line a marked Deltapsi(mt) reduction was observed after exposure to BBR 3464, but not to CDDP. The results of the study would suggest that the sensitivity to BBR 3464 observed in the CDDP-resistant OAW42MER cell line might be attributable to the ability of the trinuclear platinum complex to modify DNA in a way which is different from that of CDDP and, as a consequence, to induce different cellular responses to DNA damage such as the triggering of specific apoptotic pathways.

Attenuation of telomerase activity does not increase sensitivity of human melanoma cells to anticancer agents.

In tumour cells, replicative immortality is attained through stabilisation of telomeres by telomerase. Recent evidence suggests that telomerase plays an anti-apoptotic role. Since apoptosis is the primary mode of cell death induced by several drugs, telomerase could be involved in determining the chemosensitivity profile of tumour cells. We investigated whether inhibition of telomerase activity through a hammerhead ribozyme targeting the RNA template of telomerase influences the susceptibility of human melanoma cells to a variety of anticancer agents (platinum compounds, taxanes, topoisomerase I inhibitors). The ribozyme sequence was inserted into an expression vector and the JR8 human melanoma cell line was transfected with it. The cell clones obtained showed a reduced telomerase activity. Growth inhibition curves generated after exposure of ribozyme-transfectant clones to individual drugs were superimposable to those obtained from parental cells. Moreover, telomerase inhibition did not promote apoptosis as a cellular response to drug treatment. Overall, our results indicate that downregulation of telomerase activity does not increase the sensitivity of melanoma cells to anticancer drugs.

In vitro effect of lonidamine on the cytotoxicity of mitomycin C and BCNU in human colon adenocarcinoma cells.

The ability of lonidamine (LND), an energolytic derivative of indazole carboxylic acid, to modulate the cytotoxic activity of mitomycin C (MMC) and 1,3,bis(2-chloroethyl)-1-nitrosourea (BCNU) was investigated in two human adenocarcinoma cell lines (LoVo and HT29) expressing different sensitivity profiles to the drugs. After a 1-h treatment with MMC or BCNU, cells were postincubated for 24 h with 150-225 microM LND. In the LoVo cells, a synergistic interaction between LND and MMC or BCNU was observed at both LND concentrations. In HT29 cells, only additive effects of the drugs given in sequence were seen. Flow cytometric analysis indicated that LND was generally able to stabilise the cell cycle perturbations induced by MMC and BCNU in the two cell lines. The ability of LND to potentiate anticancer drug activity, and the consideration that LND causes side-effects different from those of conventional antitumour drugs, make this compound an attractive candidate for multidrug combination therapy in colon cancer.

Fludarabine as a modulator of cisplatin activity in human tumour primary cultures and established cell lines.

The potential of the purine analogue fludarabine (9-beta-D-arabinofuranosyl-2-fluoroadenine-5' monophosphate) as a modulator of cisplatin cytotoxicity was investigated in four established cell lines and 20 primary cultures of human melanoma and ovarian cancer. Tumour cells were exposed to fludarabine and cisplatin, alone or in combination, for 4 h. Fludarabine did not affect the growth of ovarian cancer cell lines, whereas it induced a marked and dose-dependent inhibition of proliferation in melanoma cell lines. In primary cultures of both histotypes, the purine analogue did not induce appreciable antiproliferative effects. Combined cisplatin-fludarabine treatment caused additive effects in all established cell lines. Conversely, a synergistic effect of the combination was seen in 5 of 10 melanoma and 4 of 10 ovarian cancer primary cultures, with a dose-modifying factor ranging from 2.1 to 3.9 for melanomas and from 4.0 to 7.5 for ovarian cancers, respectively. In the remaining cultures, the interaction between fludarabine and cisplatin was additive. The alkaline filter elution analysis performed on primary cultures showed that the synergistic interaction between the two drugs was paralleled by an increase in the extent and persistence of the cisplatin-induced DNA interstrand crosslinks. Our results indicate that fludarabine can enhance cisplatin cytotoxic activity in human tumour primary cultures from ovarian cancer and malignant melanoma. Such an effect may be partially due to an interference by fludarabine on cisplatin-induced DNA adduct metabolism and repair.

Inhibition of telomerase activity by a distamycin derivative: effects on cell proliferation and induction of apoptosis in human cancer cells.

In this study, we evaluated the potential of the distamycin derivative MEN 10716 as a telomerase inhibitor. Exposure of human melanoma cell extracts to MEN 10716 induced a dose-dependent inhibition of telomerase activity, with an IC50 of 24+/-3 microM. When intact JR8 melanoma cells were chronically exposed to the drug (200 microM every other day for 50 days), a marked inhibition (>80%) of the enzyme's catalytic activity was consistently observed starting from day 1. At later points in time, MEN 10716 inhibited melanoma cell proliferation and induced apoptosis. Cells surviving MEN 10716 exposure were characterised by a higher melanin content and a greater expression of p16(INK4A) protein than control cells. The effects of MEN 10716 were subsequently evaluated in different tumour cell systems. In particular, even in the H460 non-small cell lung cancer cell line, chronic exposure of the cells to the drug (100 microM every other day for 50 days) induced a consistent inhibition (>85%) of telomerase activity, a reduction of cell proliferation potential, and apoptosis. Conversely, MEN 10716 treatment did not appreciably inhibit cell proliferation in the U2-OS telomerase-negative human osteogenic sarcoma cell line. Interestingly, no variation in the mean telomere length was observed in MEN 10716-treated JR8 melanoma cells, whereas an appreciable increase in the mean telomere length was found in H460 lung cancer cells after drug exposure. Overall, the results of the study indicate that MEN 10716 is a possible telomerase inhibitor and suggest that abrogation of telomerase activity can affect cell proliferation even through pathways that are not dependent on telomere erosion.

Somatosensory extinction for meaningful objects in a patient with right hemispheric stroke.

Implicit, high level processing of extinguished objects has often been described in the visual modality. In the tactile domain, however, research on this topic is meagre and it is still uncertain whether processing of tactually presented stimuli can be affected by the same attentional disorders as visual stimuli. In this paper we describe a patient, ENM, with visual neglect and light touch extinction who, in a naming task of objects presented in the tactile modality, simultaneously to both hands, showed extinction for left hand objects. He was, nevertheless, able to make above chance Same/Different judgements on the two stimuli. We also tested two neurologically intact subjects who performed the test wearing a ski-glove on the left hand to impair the recognition of left hand objects. In these subjects, Same/Different judgements were at chance level when recognition rate was as low as that found in patient ENM. This happened when either the objects, although sharing the same name were different in shape (conditions Same-Different) or when the two objects were different with respect to the category name but were actually physically similar (conditions Different-Similar). However, when the objects were either identical or completely different, i.e., in a condition where judgement could be based simply on the physical analysis of the object shape (condition Same Identical and Different Dissimilar), their Same/Different judgements were above chance, despite the tactual deficit. Our conclusion was that patient ENM showed implicit recognition of left hand objects, at least in the Same Different and in the Different-Similar conditions, whereas, in the same conditions, normal subjects with an artificial sensory impairment did not. Our results also show that Same/Different judgements may be, in some conditions, less demanding than naming tasks, as suggested by Farah et al. Furthermore, patient ENM performed the test both with uncrossed and crossed hands. We found that extinction always affected the hand contralateral to the brain damage, although there was a tendency for a decrement of the ipsilesional hand performance in the crossed condition. We discuss these findings with reference to the most recent theories on the existence of a body centered spatial frame of reference.

Modulation of cytotoxic drug activity by mitotane and lonidamine in human adrenocortical carcinoma cells.

The ability of mitotane, a DDT derivative with adrenotoxic activity, and lonidamine, an energolytic derivative of indazole-carboxylic acid, to modulate the cytotoxic activity of doxorubicin, epidoxorubicin, cisplatin and VP16 was investigated in a human adrenocortical carcinoma cell line (SW13). A marked variability in cellular response to a 1-h treatment with the individual anticancer agents was observed. The concentrations able to inhibit SW13 cell proliferation by 50% (IC50) were 0.45 microg/ml and 0.4 microg/ml for doxorubicin and epidoxorubicin, respectively, thus indicating a relative sensitivity to anthracyclines. Conversely, the SW13 cell line displayed a marked resistance to cisplatin (IC50, 13.9 microg/ml) and VP16 (IC50, 15 microg/ml). When cells were exposed to anticancer drugs and mitotane simultaneously or in sequence, a positive modulation of anthracycline cytotoxic effects was observed. Although to a lesser extent, mitotane also increased cisplatin activity. Conversely, no potentiation was observed when mitotane was combined with VP16. Lonidamine slightly increased the cytotoxicity of epirubicin and cisplatin as individual agents. Moreover, a supra-additive effect of the three-drug (epidoxorubicin-cisplatin-lonidamine) combination was observed.

Combined effects of lonidamine and tamoxifen in human breast-cancer cell-lines.

The antiproliferative activity of lonidamine, alone or in combination with the antiestrogen tamoxifen, was studied on estrogen receptor-positive and estrogen receptor-negative human breast cancer cell lines. Lonidamine by itself induced an appreciable cytotoxic effect on all five cell lines, with 50% inhibitory concentrations (IC50) ranging from 19.5 to 54 mu M. The combination of lonidamine and tamoxifen, simultaneously administered or in sequence, provided additive effects on the estrogen receptor-negative MCF/DX cell line and a sub-additive interaction in the estrogen receptor-positive MCF7 cells. The negative interference between the two drugs could be ascribed to the marked reduction induced by lonidamine in the expression of estrogen receptor in the MCF7 cells.

Reliability of a primary culture system to test cytotoxic drug activity in human-malignant melanoma.

Optimal conditions have been defined to grow primary cultures of malignant melanoma suitable for in vitro pharmacological studies. A feasibility of primary cultures was observed in 60% of 62 clinical melanoma lymph node metastases. The neoplastic nature of the cells grown in culture, as assessed by the highly specific monoclonal antibodies anti-S100 and HMB45, was confirmed in 100% and 65% of the cases, respectively. Flow cytometric analysis showed a high stability of DNA content profiles observed in clinical samples through all the methodologic steps used to obtain in vitro cultures. The intertumor variability of the degree of the antiproliferative effect of melphalan and its relation with DNA interstrand cross-links (DNA ISC) provided preliminary evidence of the reliability of the experimental system for in vitro evaluation of anticancer drug activity.

Relevance of cell kinetic and ploidy characteristics for the thermal response of malignant-melanoma primary cultures.

We investigated die relation between the thermal sensitivity and the cell kinetics and ploidy of human malignant melanoma primary cultures. Cell suspensions from lymph node and/or cutaneous metastases of 49 patients were exposed for 1 h to 42-degrees-C. The effect of hyperthermia was assessed by an antiproliferative assay based on H-3-thymidine incorporation of cells grown in agarose for 4 days. Thermal sensitivity was observed in 10 of the 49 tumors studied (20%). In vitro thermal response as a function of proliferative activity (H-3-thymidine labeling index) was investigated in 36 melanomas. The median H-3-thymidine labeling index of sensitive tumors was 4-fold (8.1% vs 2.0%) that of resistant tumors. The relation between in vitro thermal sensitivity and flow cytometric DNA content was possible to find in 21 malignant melanomas. Thermosensitivity was found in 2 of the 3 diploid melanomas and in 2 of the 10 tumors with only one aneuploid subpopulation, whereas all multiploid tumors showed in vitro thermosistance. Our findings suggest that cell kinetic characteristics and, ploidy could be considered potential indicators of thermoresponsiveness in human malignant melanoma.

Cell growth on cordierite: an approach to the identification of reliable supports for continuous-flow solid-bed reactors.

This study aimed to assess the biocompatibility of two cordierite ceramics (DF and Cord 1014), with similar chemical composition and different porosity, as a potential support for cell growth in a continuous-flow, solid-bed reactor. The Chinese hamster ovary (CHO) cell line transfected with HBV-DHFR recombinant plasmid was seeded on cordierite or polystyrene dishes and evaluated for cell growth and production of recombinant hepatitis B surface antigen. Proliferation of the CHO cells, in terms of cell number, was generally similar in polystyrene and Cord 1014 and always lower in DF. Flow cytometric analysis showed no difference in cell cycle distribution for cells grown on different supports, and showed a two-fold increase in percentage of debris for cells grown on DF than for those grown on Cord 1014 and polystyrene culture dishes. Moreover, the morphology of cells grown on Cord 1014 did not change during the experiment, and cells were well spread and organized. Finally, total recombinant hepatitis B surface antigen production was higher on Cord 1014 than on polystyrene and DF samples. Such evidence suggests that Cord 1014 could be a promising support for growing cells in a continuous-flow, solid-bed reactor.

Differential effect of 9 beta-chloro-16, 16-dimethyl prostaglandin E2 (nocloprost) on the radiation response of human normal fibroblasts and colon adenocarcinoma cells.

The possible influence of 9 beta-chloro-16,16-dimethyl prostaglandin E2 (nocloprost) on the effect of 137Cs gamma irradiation was investigated comparatively in human normal fibroblasts and colon adenocarcinoma cells. By itself, the compound did not influence the proliferation of cells of either cell type or the clonogenic capacity of carcinoma cells. Moreover, nocloprost did not induce any DNA strand breakage, as evaluated by neutral elution, in cells of either cell type. A 2-h incubation with nocloprost before irradiation induced an enhancement of fibroblast survival after an exposure of 10 Gy. This protective effect was not observed in adenocarcinoma cells under the same treatment conditions. The amount of double-strand breaks induced by 50 Gy was reduced in normal cells but not in tumor cells exposed to the prostaglandin analog before irradiation. Moreover, incubation with nocloprost for 2 h after irradiation remarkably enhanced the rate of rejoining of DNA breaks in fibroblasts but not in adenocarcinoma cells. Overall, these findings indicate a specific radioprotective effect of nocloprost in normal cells and no influence of the compound on the cytotoxic effect of ionizing radiation on colon adenocarcinoma cells.

Cardiovascular responses to physical exercise and tyramine infusion in hypertensive and normotensive subjects.

The aim of our investigation was to assess blood pressure and heart rate variations in 20 essential hypertensive male in-patients (WHO class I and II) and in 20 normotensive healthy volunteers submitted to three provocation tests: isometric handgrip (IHG), bicycle ergometric exercise (BEE) and tyramine infusion (TI) given as i.v. boluses alternating with saline in a single-blind fashion. According to our data IHG induced a comparable rise of systolic BP, diastolic BP and heart rate both in hypertensive and normotensive subjects. BEE, compared with IHG, caused a more significant (P less than 0.01) rise in SBP and heart rate in both groups. By contrast, DBP during BEE was significantly increased in hypertensive (P less than 0.01), but slightly decreased in normotensive subjects (P = NS). TI caused a dose dependent SBP rise in both groups studied, while DBP and HR were unaffected. BP elevation was, however, more marked in hypertensive subjects. Confirming this finding significantly lower tyramine doses were required to produce the same SBP increase in hypertensives than in the normotensive volunteers. In short, SBP rise during TI and DBP rise during BEE may be the markers of an enhanced cardiovascular reactivity of hypertensive subjects. Our study suggests that BP reactivity to stress may be different according to the laboratory stress employed and also that BEE and TI are more useful than IHG for the assessment of an enhanced cardiovascular response to stress in hypertensive subjects.

Diurnal blood pressure variability in essential hypertension and vascular reactivity to isometric stress.

The present study was designed to assess the hemodynamic conditions, by means of impedance cardiography methods, and the relation existing between vascular reactivity to isometric stress (isometric handgrip test) and the day/night blood pressure variations, estimated by ABPM. Fifty unselected untreated non-obese EEH adult subjects (WHO class I) with a duration of disease not exceeding 3 years were classified as dippers or non-dippers according to commonly accepted criteria. Twenty three normotensive volunteers acted as controls. SBP, DBP, HR, CI and SVRI were assessed at rest and after IHG test. At rest dippers, non-dippers and controls showed comparable CI. SVRI were more enhanced in EEH than in controls and, although not significantly, in non-dippers than in dippers. During IHG all subjects showed a significant rise of SBP, DBP and HR; CI variations were of comparable size in all groups while SVRI increases were not. Non-dippers showed a significant SVRI rise after IHG in comparison with resting values. In dippers and in controls SVRI increment was insignificantly different in comparison with resting values. Non-dippers showed a closest correlation between BP and SVRI rise during IHG while dippers showed a less consistent association. In conclusion, our data suggest that in adults with short duration EEH the existence of non-dipper condition may be unrelated to myocardial hypertrophy. Blunted nocturnal BP fall is associated with vascular hyper-reactivity revealed by a bigger elevation of SVRI during IHG.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined effects of interferon-alpha2a and 13-cis-retinoic acid on human melanoma cell growth and STAT protein expression.

We assessed the antiproliferative effects of human recombinant interferon-alpha2a (IFNalpha2a) and 13-cis-retinoic acid (13cis-RA) on two human melanoma cell lines (JR8 and M14). Both cell lines showed a very modest sensitivity to IFNalpha2a and 13cis-RA as single agents. In JR8 cells, the combination of the two compounds consistently produced simple additive effects. In contrast, different effects of the combination were recorded in the M14 cell line depending on the treatment schedule. Specifically, an additive interaction was observed when IFNalpha2a and 13cis-RA were given in sequence, independently of the order of drug administration, whereas a supra-additive antiproliferative effect was seen when cells were simultaneously exposed to the two drugs. Exposure to 1000 IU/ml IFNalpha2a markedly increased the nuclear expression of signal transducers and activators of transcription (STAT) proteins in both cell lines. By itself 10 microM 13cis-RA did not affect STAT protein expression or modify the extent of activation of such proteins by IFNalpha2a. Results from our study showed an enhancement of the antiproliferative activity of IFNalpha2a and 13cis-RA when given in combination and suggest that such an enhancement is not mediated by a concomitant effect of 13cis-RA on STAT protein activation.

Lack of p21waf1 and p27kip1 protein induction by interferon-alpha2a in human melanoma cell lines.

The ability of human recombinant interferon-alpha2a (IFNalpha2a) to induce the expression of cyclin-dependent kinase inhibitors p21waf1 and p27kip1 consequent to signal transducers and activators of transcription (STAT) protein activation was investigated in six human melanoma cell lines with different susceptibilities to the antiproliferative effect of the cytokine. All the cell lines expressed IFNalpha and IFNalpha/beta receptors. Exposure for 24 h to IFNalpha2a markedly enhanced the nuclear expression of STAT1 and STAT2 proteins in all the cell lines. However, no induction of p21waf1 or p27kip1 was consistently observed. Overall, results from the study suggest that the induction of such cyclin-dependent kinase inhibitors is not a major mechanism for the antiproliferative effect of IFNalpha2a, at least in human melanoma cell lines.

Combined effects of lonidamine and hyperthermia on malignant melanoma and lung carcinoma surgical specimens.

The in vitro cytotoxic activity of a 1 hr-treatment with lonidamine alone or combined with hyperthermia was investigated on primary cultures obtained from 12 human malignant melanomas and 9 lung carcinomas. The study was carried out by an antiproliferative assay based upon the inhibition of incorporation of 3H-thymidine into DNA of cells grown in agarose for 4 days. Under normothermic conditions the drug did not have any cytotoxic effect on either tumor type. Hyperthermia alone also failed to influence proliferation of melanoma and lung carcinoma cells. When the same tumors were exposed to lonidamine at 42 degrees C, there was significant enhancement of drug activity in both tumor types. There was also a synergistic interaction in a percentage of tumors, which increased as a function of drug concentration.