Long telomeres at baseline and male sex are main determinants of telomere loss following chemotherapy exposure in lymphoma patients.

Although chemotherapy (CHT) exposure is an established cause of telomere attrition, determinants of telomere length (TL) dynamics after chemotherapy are poorly defined. In this study, we analyzed granulocyte telomere dynamics in 34 adult lymphoma patients undergoing first-line CHT. TL was measured by southern blot at each CHT cycle and after 1 year from CHT completion. Median age was 59 yrs (range 22-77). Median number of CHT cycles was 6 (range 3-6). The majority of patients (79%, n = 27) experienced TL shortening following CHT exposure. Mean telomere loss was 673 base pairs (bp) by cycle 6. Telomere shortening was an early event as 87% of the total telomere loss (mean 586 bp) occurred by the end of cycle 3, with no significant recovery after 1 year. A significant correlation was observed between baseline TL and total or fractional telomere loss (p < 0.001), with telomere shortening by cycle 3 observed predominantly in male patients with long telomeres at pre-treatment evaluation. Stratifying the analysis by gender and age only young women (<51 years of age) did not show significant telomere shortening following chemotherapy exposure. These findings indicate that gender and baseline TL are major determinants of TL dynamics following chemotherapy exposure in lymphoma patients.

Influence of Donor and Recipient Gender on Telomere Maintenance after Umbilical Cord Blood Cell Transplantation: A Study by the Gruppo Italiano Trapianto Di Midollo Osseo.

Physiologic loss of telomerase activity in adult life determines progressive telomere length (TL) shortening. Inflammation and oxidative damage are established causes of TL loss; moreover, males have shorter telomeres compared with females. Despite these notions, mechanisms regulating TL maintenance are poorly defined. Because umbilical cord blood (UCB) cells harbor very long telomeres, not yet exposed to environmental damages, UCB transplantation (UCBT) provides a unique experimental setting to study determinants of TL in humans. TL dynamics were analyzed on peripheral blood mononuclear cells (MNCs) from 36 patients (median age, 42 years) undergoing UCBT. TL was studied at a median of 20 months after UCBT. A significantly longer TL (mean, 8698 bp; range, 6521 to 11,960) was documented in UCBT recipients compared with age-matched healthy control subjects (mean, 7396 bp; range, 4375 to 11,108; P < .01). Among variables potentially influencing TL maintenance, including recipient features, graft type, transplant procedure, and engraftment kinetics, only donor-recipient gender combination was associated with TL, with the longest TL in women receiving male UCB (mean, 10,063 bp; range, 8381 to 11,960). To further investigate this trend, telomerase activation was assessed in vitro. Experiments showed that telomerase subunits were preferentially upregulated in male-derived bone marrow MNCs exposed ex vivo to estradiol as compared with female MNCs. This implies an increased sensitivity of male-derived MNCs to telomerase activation induced by estradiol. The results suggest that extrinsic and modifiable factors such as hormonal status and female milieu could be major determinants of TL in humans, providing the rationale for investigating hormonal-based approaches to counteract telomere erosion and aging-related diseases.

Who Should Not Be Surveilled for HCC Development after Successful Therapy with DAAS in Advanced Chronic Hepatitis C? Results of a Long-Term Prospective Study.

Background and aims: The identification of patients with Hepatitis C Virus (HCV)-positive advanced chronic liver disease (aCLD) successfully treated by Direct Acting Antiviral Agents (DAAs) who really benefit from Hepatocellular Carcinoma (HCC) surveillance programs is still a matter of debate. We performed a long-term prospective cohort study on F3-F4 HCV-positive patients achieving Sustained Virologic Response (SVR) after DAAs treatment in order to identify patients who can safely suspend surveillance. Methods: 1000 patients with HCV-positive aCLD obtaining SVR by DAAs from January 2015 to December 2017 were divided into four groups according to baseline elastographic, ultrasonographic, clinical and biochemical features: (1) Group 1: 324 patients with Liver Stiffness Measurement (LSM) ≥ 9.5 ≤ 14.5 kPa, FIB-4 < 3.25 and APRI < 1.5 (2) Group 2: 133 patients with LSM ≥ 9.5 ≤ 14.5 kPa, FIB-4 ≥ 3.25 and/or APRI ≥ 1.5 (3) Group 3: 158 patients with LSM > 14.5 kPa, FIB-4 < 3.25 and APRI < 1.5 (4) Group 4: 385 patients with LSM > 14.5 kPa, FIB-4 ≥ 3.25 and/or APRI ≥ 1.5. FIB-4 and APRI scores were calculated at baseline and at SVR achievement. Each patient was surveiled twice-yearly by ultrasound for a median follow-up of 48 months. Results: among Group 1 patients, 1/324 (0.3%) developed HCC (0.09/100 patients/year [PY]), compared to 6/133 (4.5%) Group 2 patients (1.22/100 PY, p = 0.0009), 10/158 (6.3%) Group 3 patients (1.68/100 PY, p = 0.0001), 54/385 (14.0%) Group 4 patients (4.01/100 PY, p < 0.0001). HCC incidence was significantly lower in Group 2 compared to Group 3 (p = 0.004) and in Group 3 compared to Group 4 (p = 0.009). HCC risk fell in patients showing a decrease of FIB-4/APRI scores. Conclusions: the risk of HCC occurrence is negligible in about 90% of HCV-positive patients with baseline LSM ≥ 9.5 ≤ 14.5 kPa plus FIB-4 < 3.25 and APRI < 1.5 achieving SVR. Among this particular subset of patients, FIB-4/APRI scores may represent an accurate and inexpensive tool to distinguish patients not needing long-term HCC surveillance.

Identification of the Best Cut-Off Value of PIVKA-II for the Surveillance of Patients at Risk of Hepatocellular Carcinoma Development.

Patients with cirrhosis are at risk of hepatocellular carcinoma (HCC) development and, according to current guidelines, should undergo surveillance by ultrasound at six month intervals. Due to the known limitations of surveillance strategies based on ultrasonography, the use of tumor biomarkers, although debated, is common practice in many centers. The aim of the study was to identify the best cut-off value for one of such biomarkers, protein induced by vitamin K absence, or antagonist-II (PIVKA-II). We retrospectively enrolled 1187 patients with liver cirrhosis: 205 with a diagnosis of HCC (median age 67 years, 81.0% males) and 982 without tumor (median age 64 years, 56.2% males). During a median follow-up (FU) of 34.6 (11.4−43.7) months, 118 out of 982 (12.0%) patients developed HCC. Serum PIVKA-II was assessed by chemiluminescence immunoassay on the Lumipulse® G600 II platform (Fujirebio, Tokyo, Japan). In the overall cohort (n = 1187), PIVKA-II showed an area under the curve (AUC) of 0.802 for HCC detection. The best cut-off value that maximized sensitivity was 50 mAU/mL (sensitivity = 80%, specificity = 64%). In the 982 patients without HCC at baseline, PIVKA-II > 50 mAU/mL was associated with an increased risk of HCC development during the FU (HR = 1.74, 95% CI 1.21−2.51; p = 0.003)). In conclusion, the evaluation of serum PIVKA-II showed a good performance for HCC detection; a cut-off value > 50 mAU/mL could be suitable for the surveillance of patients who are at risk of developing HCC.

Effect of COVID-19 Pandemic on Hepatocellular Carcinoma Diagnosis: Results from a Tertiary Care Center in North-West Italy.

The COVID-19 pandemic has forced us to direct most of the available resources towards its management. This has led to the neglect of all other pathologies, including cancer. The aim of this study was to verify whether the difficulty in accessing the health system has led to a reduction in new diagnoses of hepatocellular carcinoma (HCC) and whether this has already been reflected in a more advanced stage of the cancer. A single-center, retrospective study including adult patients with a new diagnosis of HCC was performed. Patients were divided into three groups: the prelockdown phase (May 2019-February 2020), the lockdown phase (March 2020-December 2020), and the postlockdown phase (January 2021-October 2021); 247 patients were included. The number of patients diagnosed with HCC distinctly diminished in the periods March 2020-December 2020 (n = 69; -35%) and January 2021-October 2021 (n = 72; -32%) as compared to the period May 2019-February 2020 (n = 106). Noteworthy was the reduced surveillance in the period January 2021-October 2021 as compared to May 2019-February 2020 (22.9% vs. 36.6%, p = 0.056). No significant changes have yet been observed in tumor characteristics (BCLC staging distribution remained unvaried, p = 0.665). In conclusion, the number of new HCC diagnoses decreased sharply in the first 2 years of the pandemic, with no worsening of the stage. A more advanced stage of the disease could be expected in the next few years in patients who have escaped diagnosis.

Serum glypican-3 for the prediction of survival in patients with hepatocellular carcinoma.

BACKGROUND: Glypican-3 (GPC-3) is a heparan sulfate proteoglycan overexpressed by hepatocellular carcinoma (HCC) cells. Several studies highlighted the diagnostic and prognostic value of GPC-3 expression in liver tissue, while data on the reliability of serum GPC-3 are limited and conflicting. We aimed to evaluate the prognostic value of serum GPC-3 in patients with HCC. METHODS: A total of 449 patients (91 F and 358 M; median age 65 [38-86] years) with a new diagnosis of HCC and available serum samples collected at tumor diagnosis were retrospectively analyzed. All patients had cirrhosis and the main underlying etiology was viral (N.=323, 72%). Barcelona Clinic Liver Cancer (BCLC) staging system was adopted for patients' classification (BCLC 0/A, N.=293, 65% vs. B/C/D, N.=156, 35%) and treatment allocation. Response to therapy was assessed by modified Response Evaluation Criteria in Solid Tumors (mRECIST). RESULTS: Median overall survival (OS) after HCC diagnosis was 30 months (95% confidence interval [CI]: 27-34). Patients with serum GPC-3>150 pg/mL showed lower overall survival (16; 95%CI: 13-24 months) compared to those with GPC-3≤150 pg/mL (36; 95%CI: 30-56 months) (Log-rank test, P<0.001). At multivariate Cox proportional-hazard regression analysis, presence of ascites (adjusted Hazard Ratio [aHR]=1.84; 95%CI: 1.23-2.74, P=0.003), BCLC stage (aHR=1.65; 95%CI: 1.39-1.97, P<0.001), mRECIST (aHR=0.33; 95%CI: 0.21-0.51, P<0.001) and GPC-3>150 pg/mL (aHR=2.02; 95%CI: 1.47-2.78, P<0.001) resulted significantly associated to overall survival. CONCLUSIONS: Serum GPC-3 resulted an independent prognostic factor for patients with HCC irrespectively from tumor stage and response to therapy.

Liver Cancer-Specific Isoform of Serine Protease Inhibitor Kazal for the Detection of Hepatocellular Carcinoma: Results from a Pilot Study in Patients with Dysmetabolic Liver Disease.

Reliable non-invasive biomarkers for the surveillance of patients at risk of hepatocellular carcinoma (HCC) development represent an unmet medical need. Recently, the liver-cancer-specific isoform of serine protease inhibitor Kazal (LC-SPIK) has been proposed as a valuable biomarker for the detection of HCC in patients with chronic liver disease of viral etiology. In the present study, we assessed the diagnostic accuracy of LC-SPIK, alone or in combination with standard serologic biomarkers (i.e., alpha-fetoprotein and protein induced by vitamin K absence or antagonist-II, PIVKA-II), for the detection of HCC among patients with dysmetabolic liver disease. A total of 120 patients with non-alcoholic fatty liver disease (NAFLD), including 62 patients with a diagnosis of HCC and 58 with cirrhosis but without tumor, were retrospectively analyzed. The serum levels of LC-SPIK were measured by enzyme-linked immunosorbent assay (ImCare Biotech, Doylestown, PA). The serum LC-SPIK values were significantly different between patients with HCC (24.3, 17.6−39.8 ng/mL) and those with cirrhosis but without tumor (11.7, 8.7−18.2 ng/mL) (p < 0.001). By receiver operating characteristic curve analysis, we observed an area under the curve (AUC) of 0.841 for the detection of HCC; the combination with PIVKA-II further increased the accuracy to AUC = 0.926 (cross-validation). The promising results observed in the present pilot study foster additional research to investigate the usefulness of LC-SPIK for the stratification of the risk of HCC development in patients with NAFLD and advanced liver disease.

Myeloablative doses of yttrium-90-ibritumomab tiuxetan and the risk of secondary myelodysplasia/acute myelogenous leukemia.

BACKGROUND: Because the long-term toxicity of myeloablative radioimmunotherapy remains a matter of concern, the authors evaluated the hematopoietic damage and incidence of secondary myelodysplastic syndrome and acute myelogenous leukemia (sMDS/AML) in patients who received myeloablative doses of the radiolabeled antibody yttrium-90 (9°Y)-ibritumomab tiuxetan. METHODS: The occurrence of sMDS/AML was investigated prospectively in 53 elderly patients with non-Hodgkin lymphoma (NHL) who underwent an autograft after high-dose radioimmunotherapy (HD-RIT) myeloablative conditioning with 9°Y-ibritumomab tiuxetan. Bone marrow (BM) hematopoietic progenitors and telomere length (TL) also were investigated. RESULTS: At a median follow-up of 49 months, 4 patients developed sMDS/AML at 6 months, 12 months, 27 months, and 36 months after HD-RIT, and the 5-year cumulative incidence of sMDS/AML was 8.29%. A significant but transient decrease in BM granulocyte-macrophage progenitors was observed; whereas multilineage, erythroid, and fibroblast progenitors were unaffected. A significant and persistent shortening of BM TL also was detected. A matched-pair analysis comparing the study patients with 55 NHL patients who underwent autografts after chemotherapy-based myeloablative conditioning demonstrated a 8.05% 5-year cumulative incidence of sMDS/AML. CONCLUSIONS: HD-RIT for patients with NHL was associated with 1) limited toxicity on hematopoietic progenitors, 2) accelerated TL shortening, and 3) non-negligible incidence of sMDS/AML, which nevertheless was comparable to the incidence observed in a matched group of patients who received chemotherapy-based conditioning. Thus, in the current series of elderly patients with NHL, the development of sMDS/AML was not influenced substantially by HD-RIT.

Higher Efficiency of Percutaneous Microwave (MWA) Than Radiofrequency Ablation (RFA) in Achieving Complete Response in Cirrhotic Patients with Early Hepatocellular Carcinoma.

BACKGROUND: Contrasting data are available in the literature regarding the superiority of percutaneous microwave ablation (MWA) or radiofrequency ablation (RFA) in very early or early (BCLA 0 or A) hepatocellular carcinoma (HCC). AIMS: The primary outcome was to compare the efficacy of RFA and MWA in achieving complete response in cirrhotic patients with early and very early HCC. The secondary outcomes were to evaluate the overall survival and the recurrence rate. METHODS: A retrospective, observational, single-center study was performed. Inclusion criteria were liver cirrhosis, new diagnosis of a single node of HCC measuring a maximum of 50 mm or up to three nodules with diameter up to 35 mm, treatment with RFA or MWA. Radiological response was evaluated with multiphasic contrast-enhanced Computed Tomography or Magnetic Resonance Imaging at 5-7 weeks after thermal ablation. Complete response was defined when no vital tissue was detected after treatment. RESULTS: Overall, 251 HCC patients were included in this study; 81 patients were treated with MWA and 170 with RFA. The complete response rate was similar in MWA and RFA groups (out of 331 nodules, 87.5% (91/104) were treated with MWA and 84.2% (186/221) were treated with RFA, p = 0.504). Interestingly, a subanalysis demonstrated that for 21-35 mm nodules, the probability to achieve a complete response using MWA was almost 5 times higher than for RFA (OR = 4.88, 95% CI 1.37-17.31, p = 0.014). Moreover, recurrence rate in 21-35 mm nodules was higher with RFA with respect to MWA (31.9% versus 13.5%, p = 0.019). Overall survival was 80.4% (45/56) when treated with MWA and 62.2% (56/90) when treated with RFA (p = 0.027). No significant difference was observed between MWA and RFA treatment in the 15-20 mm nodules group. CONCLUSION: This study showed that MWA is more efficient than RFA in achieving complete response in HCC nodules with 21 to 35 mm diameter.

Prognostic Role of Serum Cytokeratin-19 Fragment (CYFRA 21-1) in Patients with Hepatocellular Carcinoma.

Keratin 19 (K19) is a cancer stem cell marker expressed by a subpopulation of hepatocellular carcinoma (HCC), associated with tumor aggressiveness. We evaluated the prognostic value of serum K19 fragment (CYFRA 21-1), in comparison or in combination with alpha-fetoprotein (AFP) and protein induced by vitamin-K absence or antagonist-II (PIVKA-II), in patients with HCC. A total of 160 patients (28F/132M; median age 62, range 44-86 years) with a new diagnosis of HCC and available serum samples collected at tumor diagnosis were analyzed retrospectively. Median overall survival (OS) after HCC diagnosis was 35.1, 95% CI 27.1-70.5 months. Multivariate Cox regression analysis showed that CYFRA 21-1 > 2.7 ng/mL (hazard ratio (HR) = 3.39, p < 0.001), AFP > 20 ng/mL (HR = 2.27, p = 0.007), and PIVKA-II > 200 mAU/mL (HR = 2.17, p = 0.020) were independent predictors of OS. The combination of biomarkers positivity allowed us to stratify patients with HCC into four risk categories associated with a progressively lower survival probability (log-rank test, p < 0.001). CYFRA 21-1 resulted an independent prognostic factor of patients with HCC and its combination with AFP and PIVKA-II might be useful to tailor personalized treatment strategies.

Alpha-Fetoprotein, Protein Induced by Vitamin K Absence or Antagonist II and Glypican-3 for the Detection and Prediction of Hepatocellular Carcinoma in Patients with Cirrhosis of Viral Etiology.

International guidelines recommend the use of ultrasound as a surveillance tool for hepatocellular carcinoma (HCC) in patients with cirrhosis, while the role of serum biomarkers is still debated. We investigated serum alpha-fetoprotein (AFP), protein induced by vitamin K absence or antagonist II (PIVKA-II) and glypican-3 (GPC-3) diagnostic accuracy for HCC detection and prediction in patients with liver cirrhosis of viral etiology under surveillance. A total of 349 patients (200 cirrhosis and 149 HCC) were enrolled. The 200 patients with cirrhosis consisted of 114 patients still HCC-free after 36 months of follow-up and 86 patients that developed HCC after 13.8 (11.0-19.8) months. AFP, PIVKA-II and GPC-3 were measured in serum samples collected at tumor diagnosis in the 149 patients with HCC, and at the beginning of follow-up in the 200 patients with cirrhosis. The higher performance for HCC detection was observed for PIVKA-II (area under the curve (AUC) = 0.790), followed by AFP (AUC = 0.737) and GPC-3 (AUC = 0.637); the combination of AFP + PIVKA-II improved the diagnostic accuracy to AUC = 0.822. Serum PIVKA-II values, but not AFP and GPC-3, were significantly higher in the 86 cirrhotics that developed HCC compared with the 114 cirrhotics still HCC-free after 36 months of follow-up (p = 0.020). PIVKA-II ≥ 55 mAU/mL allowed to identify patients with cirrhosis at higher risk of HCC development (Log-rank test, p < 0.001; adjusted Hazard Ratio = 1.99, p = 0.001). In conclusion, the measurement of PIVKA-II in patients with cirrhosis may be useful to tailor personalized surveillance strategies.

Clinical heterogeneity in a family with DKC1 mutation, dyskeratosis congenita and Hoyeraal-Hreidarsson syndrome in first cousins.

Dyskeratosis congenita (DC) is an inherited bone marrow failure disorder characterized by mucocutaneous features (skin pigmentation, nail dystrophy and oral leukoplakia), pulmonary fibrosis, hematologic and solid malignancies. Its severe form, recognized as Hoyeraal-Hreidarsson syndrome (HHS), also includes cerebellar hypoplasia, microcephaly, developmental delay and prenatal growth retardation. In literature phenotypic variability among DC patients sharing the same mutation is wellknown. To our knowledge this report describes for the first time a family of DC patients, characterized by a member with features of classic DC and another one with some features of HHS, both with the same mutation in DKC1. Our family confirms again that one mutation can be associated with different phenotypes and different hematological manifestations. It's possible to speculate that there are likely to be patients who do not clinically fit neatly into either classical DC or HHS, but whose clinical features are due to mutations in DKC1 or in genes responsible for autosomal DC/HHS.

Telomere shortening in Ph-negative chronic myeloproliferative neoplasms: a biological marker of polycythemia vera and myelofibrosis, regardless of hydroxycarbamide therapy.

The purpose of this study was to investigate telomere length (TL) in Ph-negative chronic myeloproliferative neoplasms (Ph-neg-CMNs), and the possible association of TL with disease progression and hydroxycarbamide (HU) treatment. TL was analyzed in peripheral blood samples from 239 patients with Ph-neg-CMNs, including polycythemia vera (PV), essential thrombocythemia and myelofibrosis (MF), and compared with age-matched healthy control subjects (CTR), along with some cases of secondary erythrocytosis (SE). More than half of the patients with CMN received at least 1 year of cytoreduction, mainly HU, before TL analysis. JAK2 mutation analysis was performed as well. TL was significantly shortened in patients with CMN compared with CTR (p < 0.0001). PV and MF showed the most pronounced decrease (p < 0.0001), whereas both essential thrombocythemia and SE showed no significant difference in TL compared with CTR. A short TL correlated with JAK2-V617F allele burden greater than 50% (p = 0.0025), age (p = 0.0132) and diagnosis of PV (p = 0.0122). No correlation was found with disease duration, history of thrombosis, cytoreductive treatment, antiaggregation agents, adverse cytogenetics, phlebotomies, or time to evolution to MF. In summary, TL is distinctly shortened in PV and MF, and it inversely correlates with JAK2V617F allele burden. In addition, HU is unlikely to contribute to telomere erosion. Lastly, PV and SE significantly differ in TL. Therefore, TL could be an additional diagnostic marker to identify and monitor Ph-neg-CMN patients.

Multiple courses of G-CSF in patients with decompensated cirrhosis: consistent mobilization of immature cells expressing hepatocyte markers and exploratory clinical evaluation.

INTRODUCTION: Bone marrow-derived cells (BMCs) include stem cells capable of self-renewal and differentiation into a variety of cell types. Administration of granulocyte colony-stimulating factor (G-CSF) induces the circulation of BMCs in the peripheral blood. A phase II prospective trial was carried out for evaluation of BMC mobilization induced by multiple courses of G-CSF in cirrhotic patients. PATIENTS AND METHODS: Fifteen patients with advanced liver cirrhosis (Child-Pugh score ≥6 points) were enrolled and treated with a 3-day G-CSF course, administered at 3-month intervals for a total of four courses. BMC mobilization was assessed by evaluating CD34+ve cells using flow cytometry. Expressions of multiple hepatic and stem markers were assessed on mobilized CD34+ve cells. Feasibility and safety were explored; clinical and adverse events were compared to those of a control group. Telomere length was monitored to rule out early cell aging caused by G-CSF. RESULTS: A significant increase in G-CSF-induced circulating CD34+ve cells was consistently observed, although a progressive reduction of peak values was documented from cycle I to IV (p < 0.005). Mobilized CD34+ve cells expressed both stem and multiple hepatocyte markers, including mRNA of albumin and CYP2B6 (cytochrome P2 B6). Treatment was well tolerated, with no severe adverse events and no significant telomere length shortening following G-CSF. The procedure was safe. Overall, ten patients had either improved or had stable liver function tests (such as the Child-Pugh score), whereas five worsened and died from liver-related causes. CONCLUSION: This study demonstrates that G-CSF can be safely administrated up to four times over a 1-year period in decompensated cirrhotic patients. The repeated BMC mobilization favors the circulation of stem cells coexpressing hepatic markers and mRNA of liver-related genes.

Multipotent mesenchymal stromal stem cell expansion by plating whole bone marrow at a low cellular density: a more advantageous method for clinical use.

Mesenchymal stem cells (MSCs) are a promising source for cell therapy due to their pluripotency and immunomodulant proprieties. As the identification of "optimal" conditions is important to identify a standard procedure for clinical use. Percoll, Ficoll and whole bone marrow directly plated were tested from the same sample as separation methods. The cells were seeded at the following densities: 100 000, 10 000, 1000, 100, 10 cells/cm(2). After reaching confluence, the cells were detached, pooled and re-plated at 1000, 500, 100, and 10 cells/cm(2). Statistical analyses were performed. Cumulative Population Doublings (PD) did not show significant differences for the separation methods and seeding densities but only for the plating density. Some small quantity samples plated in T25 flasks at plating densities of 10 and 100 cells/cm(2) did not produce any expansion. However, directly plated whole bone marrow resulted in a more advantageous method in terms of CFU-F number, cellular growth and minimal manipulation. No differences were observed in terms of gross morphology, differentiation potential or immunophenotype. These data suggest that plating whole bone marrow at a low cellular density may represent a good procedure for MSC expansion for clinical use.

The aging effect of chemotherapy on cultured human mesenchymal stem cells.

Various agents, including chemotherapeutic drugs, can induce cell senescence. However, the mechanisms involved in the aging pathway, particularly the stress that chemotherapy imposes on telomeres, are still undefined. To address these issues, human mesenchymal stem cells (MSCs) were assessed as target cells to investigate the initiation of the aging process by chemotherapy. The MSCs were obtained from bone marrow (BM) cells from normal adults and grown in the presence of platelet lysates. Cultured MSCs were identified for immunophenotype, and for growth and differentiation properties. The MSCs were exposed to 10 nM doxorubicin and 500 ng/mL etoposide, sublethal doses that induce DNA double-stranded breaks. Telomere length (TL) was assessed by flow-fluorescence in situ hybridization and Southern blotting. Initial TL shortening was detectable in MSCs at 5 days after drug exposure, with progressive reduction compared with untreated cells at 7, 14, 21, and 28 days in culture. After a single exposure, MSCs were unable to regain the lost telomere sequences for up to 28 days in culture. The ATM phosphorylation was documented early after drug exposure, while no telomerase activation was observed. Chemotherapy-induced TL shortening was associated with reduced clonogenic activity in vitro and accelerated adipose differentiation. Analogous behavior in the differentiation pattern was observed in naturally aged MSCs. These results indicate that cultured MSCs represent a useful cellular model to investigate novel drugs that may favor or, conversely, might prevent TL loss in human stem cells. The TL shortening is a permanent signature of previous chemotherapy-mediated DNA damage, and predicts impaired proliferative and differentiation potential.

The issue of refractory disease in follicular and other lymphoma subtypes / A refratariedade no linfoma folicular e em outros linfomas

The outcome of lymphoma has definitely improved over the last few decades which is mainly due to the introduction and development of novel and effective therapeutic approaches. Nevertheless, a small though notable group of patients may display a poor response to treatments, with a true refractoriness or a transient response followed by early relapse. The present review addresses the issue of refractory disease among patients with lymphoma, focusing on the overall incidence and the main clinical aspects associated with refractoriness.

A evolução dos linfomas tem sido definitivamente melhorada ao longo das últimas décadas. Isto se deve principalmente devido à introdução e desenvolvimento de novas e efetivas abordagens terapêuticas. Apesar disto, uma pequena parcela deste notável grupo de pacientes pode apresentar uma pobre resposta aos tratamentos, com uma verdadeira refratariedade, ou com resposta transitória e precocemente uma recidiva. A presente revisão aborda este assunto da doença refratária nos pacientes com linfoma, enfocando sua incidência global e os principais aspectos clínicos associados à refratariedade.