Direct introgression of untapped diversity into elite wheat lines

The effective utilization of natural variation has become essential in addressing the challenges that climate change and population growth pose to global food security. Currently adopted protracted approaches to introgress exotic alleles into elite cultivars need substantial transformation. Here, through a strategic three-way crossing scheme among diverse exotics and the best historical elites (exotic/elite1//elite2), 2,867 pre-breeding lines were developed, genotyped and screened for multiple agronomic traits in four mega-environments. A meta-genome-wide association study, selective sweeps and haplotype-block-based analyses unveiled selection footprints in the genomes of pre-breeding lines as well as exotic-specific associations with agronomic traits. A simulation with a neutrality assumption demonstrated that many pre-breeding lines had significant exotic contributions despite substantial selection bias towards elite genomes. National breeding programmes worldwide have adopted 95 lines for germplasm enhancement, and 7 additional lines are being advanced in varietal release trials. This study presents a great leap forwards in the mobilization of GenBank variation to the breeding pipelines.

Analysis of mismatch repair (MMR) proteins expression in a series of malignant pleural mesothelioma (MPM) patients

BACKGROUND

Promising results have been reported with immune checkpoint inhibitors (ICI) in a small proportion of MPM patients. MMR deficiency (dMMR) has been well described in several malignancies and was approved as a biomarker for anti-PD-1 inhibitors. Next generation sequencing (NGS) data demonstrated that 2% of MPM harbor microsatellite instability. The aim of this study is to characterize MMR by immunohistochemistry (IHC) in a series of MPM including a subset of patients treated with immunotherapy.

METHODS

Tumors of 159 MPM p diagnosed between 2002 and 2017 were reviewed. Formalin-fixed, paraffin-embedded tissue was stained for MLH1, MSH2, MSH6 and PMS2 and tumors were classified as dMMR (MMR protein expression negative) and MMR intact (all MMR proteins positively expressed). We retrospectively collected clinical outcomes under standard chemotherapy and experimental immunotherapy in the entire cohort.

RESULTS

MMR protein expression was analyzed in 158 samples with enough tissue and was positive in all of the cases. Twenty two patients received ICI with anti-CTLA4 or anti-PD-1 blockade in clinical trials, 58% had a response or stable disease for more than 6 m, with median progression-free survival (PFS) of 5.7 m (2.1-26.1 m). The median overall survival (mOS) in all population was 15 months (m) (13.5-18.8 m). In a multivariable model factors associated to improved mOS were PS 0, neutrophil-lymphocyte ratio (NLR) < 5 and epithelioid histology (p < 0.001).

CONCLUSIONS

In our series we were unable to identify any MPM patient with dMMR by IHC. Further studies are needed to elucidate potential predictive biomarkers of ICI benefit in MPM.

Dual MET and ERBB inhibition overcomes intratumor plasticity in osimertinib-resistant-advanced non-small-cell lung cancer (NSCLC)

Background

Third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as osimertinib are the last line of targeted treatment of metastatic non-small-cell lung cancer (NSCLC) EGFR-mutant harboring T790M. Different mechanisms of acquired resistance to third-generation EGFR-TKIs have been proposed. It is therefore crucial to identify new and effective strategies to overcome successive acquired mechanisms of resistance.

Methods

For Amplicon-seq analysis, samples from the index patient (primary and metastasis lesions at different timepoints) as well as the patient-derived orthotopic xenograft tumors corresponding to the different treatment arms were used. All samples were formalin-fixed paraffin-embedded, selected and evaluated by a pathologist. For droplet digital PCR, 20 patients diagnosed with NSCLC at baseline or progression to different lines of TKI therapies were selected. Formalin-fixed paraffin-embedded blocks corresponding to either primary tumor or metastasis specimens were used for analysis. For single-cell analysis, orthotopically grown metastases were dissected from the brain of an athymic nu/nu mouse and cryopreserved at -80°C.

Results

In a brain metastasis lesion from a NSCLC patient presenting an EGFR T790M mutation, we detected MET gene amplification after prolonged treatment with osimertinib. Importantly, the combination of capmatinib (c-MET inhibitor) and afatinib (ErbB-1/2/4 inhibitor) completely suppressed tumor growth in mice orthotopically injected with cells derived from this brain metastasis. In those mice treated with capmatinib or afatinib as monotherapy, we observed the emergence of KRAS G12C clones. Single-cell gene expression analyses also revealed intratumor heterogeneity, indicating the presence of a KRAS-driven subclone. We also detected low-frequent KRAS G12C alleles in patients treated with various EGFR-TKIs.

Conclusion

Acquired resistance to subsequent EGFR-TKI treatment lines in EGFR-mutant lung cancer patients may induce genetic plasticity. We assess the biological insights of tumor heterogeneity in an osimertinib-resistant tumor with acquired MET-amplification and propose new treatment strategies in this situation.

Long-term results of high-dose chemotherapy and autologous stem cell rescue for high-risk neuroblastoma patients: a report of the Spanish working party for BMT in children (Getmon)

The authors retrospectively analyzed the long-term outcome of 67 patients over 1 year of age at diagnosis with high-risk neuroblastoma (stage 4 or stage 3 with N-myc amplification) who were treated with megatherapy and stem cell rescue from 1984 to 1998. Median age at transplant was 4 years (range 1.6-15 years). The source of cells was peripheral stem cells in 29 and bone marrow in 38 patients. In 12 patients, an in vitro purging of bone marrow harvest was performed. Most patients were conditioned with melphalan, BCNU, and VM-26. After transplant 19 patients received complementary treatment with IL-2 (16) or 13-cis-retinoic acid (3). Six patients (8%) died from transplant-related toxicity and 39 from disease progression. Three patients were alive with active disease at the time of analysis. Nineteen patients are alive and disease-free at a median follow-up of 104 months. Five-year event-free survival is 0.30. Survival of patients who received a purged graft was not significantly better than the rest. Post-transplant complementary treatment significantly improved overall and event-free survival (p = .01 and p = .04, respectively).

Autologous stem cell transplantation for advanced Hodgkin's disease in children. Spanish group for BMT in children (GETMON), Spain

This study evaluates the outcome of myeloablative chemo-radiotherapy and autologous stem cell transplantation (ASCT) in children with Hodgkin's disease (HD). Twenty children aged 5 to 18 years (median 10.8 years) at diagnosis, with relapsed, refractory or very poor prognosis HD, underwent ASCT in eight hospitals of our country. Status at transplant was: second complete remission (CR2): n = 12; further CR (CR >2): n = 3, partial remission (PR): n = 2, relapse: n = 2 and first CR (CR1): n = 1. Eighteen patients received chemotherapy-based conditioning regimens: cyclophosphamide, carmustine and etoposide (CBV): 11 (55%), carmustine, etoposide, cytarabine and melphalan (BEAM): 5, other: 2; and two patients were conditioned with TBI/Cy. Peripheral blood (PB) was the source of progenitor cells in 12 patients, BM in seven, and BM plus PB, in one. All patients engrafted. One patient died of sepsis and multiorgan failure at day 28 after transplantation. All four patients with measurable disease (PR or relapse) at transplantation attained complete remission. Five patients relapsed 5-34 months after transplant (median: 11 months). Eighteen children remain alive with a median survival time of 40 months. The projected 5-year overall survival and event-free survival (EFS) rates were 0.95 and 0.62. High-dose therapy with stem cell rescue can lead to durable remissions in children with advanced HD. Bone Marrow Transplantation (2000) 25, 31-34.

Pulmonary enterovirus infections in stem cell transplant recipients

In recent years, it has been recognised that the community respiratory viruses are a frequent cause of upper and lower respiratory tract infections in immunocompromised hosts such as bone marrow transplant recipients. By contrast, infections by non-polio enteroviruses have rarely been reported after stem cell transplantation. We present four cases of acute respiratory illness with enterovirus isolated as the sole pathogen from bronchoalveolar lavage. All four patients developed pneumonia and three died of progressive pneumonia, which reflects the severity of this complication. We conclude that enteroviral pulmonary infections may be a cause of severe pneumonia in immunocompromised hosts.

Mutational analysis of p53 in 16 cases of acute lymphoblastic leukemia and Burkitt's lymphoma

BACKGROUND AND OBJECTIVE

Improvements in therapy for patients with B-cell acute lymphoblastic leukemia (ALL) and Burkitt's lymphoma (BL) depend on the identification of subsets of patients who require more intensive therapy. Abnormalities of the p53 gene are the most common molecular lesions in human cancer, and may be of prognostic significance in hematologic malignancies. In this study, we examined the p53 gene status in a group of patients with ALL/BL to determine whether some types of mutants were more frequent in this selected group of patients.

METHODS

We selected a group of 16 patients with acute lymphoblastic leukemia (ALL) and Burkitt's lymphoma (BL) in order to investigate the presence of p53 mutations. DNA obtained from affected organs (bone marrow, lymph node and a renal mass) was used for the molecular studies. Single-strand conformation polymorphism (SSCP) analysis of exons 5 to 9 of the gene was used to detect p53 mutants. After detecting an abnormal migration pattern on the SSCP, mutations were determined by direct sequencing.

RESULTS

Point mutations were found in eight patients; a misense mutation in seven cases and a non-sense mutation in one case. The normal allele was also identified in 7 mutated samples. The same mutation at codon 282 was identified in three different patients, in whom an identical conformer was detected after SSCP analysis. Mutation at codon 282 was present in an extramedular relapse (renal) appearing after a BMT. No such alteration was present in the bone marrow analyzed at the same time.

INTERPRETATION AND CONCLUSIONS

Our findings suggest that p53 mutations are quite frequent in recognized clinical groups. The criteria chosen in this study allowed us to identify a high percentage of the samples with mutation. Different malignant phenotypes could be determined by functional heterogeneity of p53 mutants.

High-dose systemic interleukin-2 therapy in stage IV neuroblastoma for one year after autologous bone marrow transplantation: pilot study

Despite intensified chemotherapy protocols, including autologous bone marrow transplantation (ABMT), stage IV neuroblastoma has a poor prognosis, and modern therapeutic trends are aimed at the eradication of minimal residual disease, which is though to be the main factor leading to relapse. In this pilot study, we report the systemic administration of high doses of interleukin-2 after ABMT in four patients. Five day cycles of IL-2 at a dose of 18 x 10(6) IU/m2/day were administered at variable time intervals as frequent as it was necessary to maintain the levels of natural killer (NK) cytotoxic activity higher than the median control value (40 LU/ml blood) throughout 1 year from the start of first IL-2 treatment. After IL-2 infusion, NK and LAK activities increased significantly (median 742 x 10(-3) LU/ml blood and 186.8 x 10(-3) LU/ml blood, respectively). Toxicities were transient and no life-threatening complications were observed. Fever, anorexia, skin rash and enlarged liver were always present. Anaemia, thrombocytopenia, leukocytosis, lymphocytosis and and eosinophilia occurred following most of the IL-2 courses. Although the small number of patients does not allow an estimation of the immunomodulatory-antineoplasic effects of IL-2, the results seem promising for the management of neuroblastoma patients.

Interleukin-2 in neuroblastoma: clinical perspectives based on biological studies

Stage IV neuroblastoma (NB) is a disease with a poor prognosis. Chemotherapeutical intensification and hematological rescue with autologous bone marrow transplantation (ABMT) achieve some complete remissions (CR), but most patients relapse during the first year. Immunotherapy could be an alternative in this situation of high risk of relapse due to residual disease and ABMT-related immunodepression. Ten stage IV NB patients in CR or very good partial remission have been treated with recurrent 5-day cycles of high doses of Interleukin-2 (IL2) after ABMT throughout one year (usually 5-6 cycles). Natural killer (NK) and lymphokine-activated killer (LAK) cytotoxic activities, as well as phenotype and number of circulating NK cells were determined, before and after each course of IL2 treatment. The effects promoted by IL2 varied during treatment: early cycles of IL2 induced a great extent of cell expansion, mainly on CD3-/CD16-/CD56+bright and CD8+dim cell phenotypes; conversely, late courses of IL2 promoted higher NK cytotoxic activity but a lesser increase on circulating NK cells. The induction of LAK activity did not significantly differ from early and late IL2 treatments. Clinical results are still inconclusive due to the small number of patients. The median follow-up of patients treated with IL2 is 24 months and the disease free survival (DFS) probability is 0.80 +/- 0.12 vs 0.16 +/- 0.15 from a historical control with identical treatment, but in the absence of IL2 treatment (p < 0.005). IL2 treatment-related toxicity was mild and no interruption of the treatment was required. Extremely accurate hydric control was carried out to avoid, as much as possible, the consequences of vascular leak syndrome, one of the most important toxic effects of IL2 treatment. The results presented here suggest an evolution of NK activity during IL2 treatment after ABMT, which should be taken into account for the designing of new immunotherapeutical protocols and opens a promising perspective in treatment of stage IV neuroblastoma.

[Neuropsychological disorders due to left fronto-striatal lesions: a longitudinal study of an adolescent]

Relatively little is known of the neuropsychological consequences of isolated frontal-striatal lesions in children. We study the case of an adolescent boy who suffered a stroke in the left hemisphere at the age of 11. In addition to the expected frontal dysfunctions, the patient at first suffered lowered IQ and attention disorder with hyperactivity. Four years after the stroke, only frontal lobe dysfunctions (difficulties in planning, anticipating, responding, generating words, attending, and sequencing with loss of mental flexibility) persisted. The functional recovery might have come about because the right hemisphere striate assumed functions of the left hemisphere. The persistence of frontal dysfunctions favors specialization of the left frontal lobe and the relatively early maturity of this cortical structure.

Progression of natural immunity during one-year treatment of residual disease in neuroblastoma patients with high doses of interleukin-2 after autologous bone marrow transplantation

The aim of this work was to monitor the functional and phenotypic variations of natural killer (NK) cells in seven children with stage IV neuroblastoma (NB) treated with recurrent 5-day cycles of interleukin-2 (IL-2) at a dose of 18 x 10(6) IU/m2/d by continuous intravenous infusion. All patients who entered the study had no detectable disease after hematologic recovery from intensive chemotherapy and autologous bone marrow transplantation (ABMT). To evaluate the effect of this treatment on tumor relapse, IL-2 immunotherapy was adjusted to maintain levels of NK activity above those of age-matched controls (threshold of 40 lytic units [LU]/10(9) mononuclear cells) during a 1-year period since hematologic recovery of ABMT. The levels of NK and endogenous lymphokine-activated killer (eLAK) cell cytotoxic activities, as well as phenotype-differentiated lymphocyte counts, were determined from patients' freshly isolated peripheral blood mononuclear cells (MNC). Data were analyzed at different points between each cycle of IL-2, and before and 36 hours after each infusion. NK and eLAK activities significantly increased in response to IL-2. Both cytotoxic parameters correlated with the serum levels of the soluble IL-2 receptor (sIL-2R). IL-2 increased the amounts of NK and T cell subsets but not of B cells. The effects of IL-2 were time-dependent. Early cycles of IL-2 preferentially increased cell numbers, especially of cells bearing a CD3-/CD16-/CD56+bright and CD8+dim phenotype. Conversely, late courses promoted higher cytotoxic effects but with a smaller increase in NK and T cell counts; the main NK subset became CD16+, and CD8+dim cells remained a minor subset. It is worthy to note that the patient who relapsed after completing immunotherapy showed only a slight increase of the NK subset in response to IL-2. These results show the feasibility of sustaining an increased NK activity during 1 year after ABMT in children with advanced neuroblastoma and suggest the occurrence of changes in the functional and phenotypic characteristics of the NK cells generated throughout the 1-year treatment.

Impact of megatherapy in children with high-risk Ewing's tumours in complete remission: a report from the EBMT Solid Tumour Registry

The European BMT Solid Tumour Registry (EBMT-STR) received reports from 21 European transplant centers on 63 patients (50 Ewing's sarcomas and 13 peripheral neuroectodermal tumours) in first (n = 32) or second CR (n = 31) consolidated with megatherapy and BM and/or PSC rescue between December 1982 and November 1992. There were 31 males and 32 females with a median age of 12 years (range 1-30 years) at megatherapy. The median follow-up time since megatherapy is 4 years (range 1 month to 10 years), Thirty-two patients with metastatic disease at diagnosis (22 had metastases to the bone and/or bone marrow) and consolidated in CR1 reached an actuarial event-free survival (EFS) of 21% at 5 years. Thirty one patients in CR2 achieved an actuarial EFS of 32% at 5 years. Favourable outcome was limited to relapse patients with localised disease at initial diagnosis. Distant relapse had a more favourable prognosis than local failure. Analysis of the different megatherapy strategies could not identify a significantly superior approach, nor is there convincing evidence in favour of double graft procedures. From the above results it appears that consolidation treatment by megatherapy contributes to improved EFS rates in high-risk patients compared with historical experience. Major questions for the future to be addressed prior to randomised studies include agreement on the definition of high-risk patients and the most efficient megatherapy procedure.

Bone marrow transplantation in 46 pediatric patients with non-Hodgkin's lymphoma. Spanish Working Party for Bone Marrow Transplantation in Children

We report a retrospective analysis on 46 pediatric patients (median age 9 years, range 1-17 years) with non-Hodgkin's lymphoma (NHL), transplanted in six Spanish centers. Fourteen patients underwent allogeneic bone marrow transplantation (BMT) and 32 autologous BMT. Most patients were boys (36 of 46). Twenty one cases were of lymphoblastic lymphoma, 19 Burkitt's lymphoma and six diffuse large cell lymphoma. Maximal Murphy's stage any time before BMT was stage III in 17 cases and stage IV in 29 cases. At BMT, 13 cases were in first CR, 21 in second CR, seven in third CR, four with sensitive active disease and one with refractory disease. All patients transplanted in CRl were considered candidates for BMT because of delayed CR (two cases), failure of the first-line therapy (seven cases) or central nervous system (CNS) or BM infiltration at diagnosis (four cases). Conditioning therapy included TBI in 33 patients and 13 cases were conditioned with chemotherapy alone. Toxic mortality was 13% (three of 14 in the allogeneic BMT group and three of 32 in the autologous group). No toxic deaths were registered in 13 patients undergoing BMT in CR1 (three allogeneic BMT and ten autologous BMT). Twelve patients relapsed 1-7 months after BMT. Overall event-free survival (EFS) was 58% (42-73%; confidence interval (CI) 95%), with a median follow-up of 33 months. EFS was similar for allogeneic BMT and autologous patients. Disease status at BMT was the only predictive factor for EFS (P < 0.01). There were no significant differences between patients in CR1 (82.5%) and CR2 (68%).(ABSTRACT TRUNCATED AT 250 WORDS)

Autologous bone marrow transplantation for pediatric Wilms' tumor: the experience of the European Bone Marrow Transplantation Solid Tumor Registry

This survey includes 25 children with Wilms' tumor undergoing high-dose chemotherapy associated with autologous bone marrow transplantation (ABMT) in the period June 1984-December 1991 and enrolled in the European Bone Marrow Transplantation Registry for Solid Tumors. At diagnosis, 12 children presented stage IV disease, 5 stage III, 3 stage II, and 5 stage I. Before ABMT, 21 children had 1 to 4 relapses (median 1); 13 achieved a second or subsequent complete remission (CR), four stage IV children failed to respond to first line treatment and achieved either CR (3 patients), or partial remission (PR) after second line therapy. At high-dose chemotherapy, 17 children were in CR and 8 had measurable disease. Seven different high-dose regimens were administered, even if 20 children received melphalan mostly associated with vincristine and 8 involved field radiotherapy. Three children died early of pneumonitis; 2 developed an acute transient renal failure, 1 a chronic renal failure. Out of the 8 children with target disease at graft, 2 died of toxicity, 5 achieved CR, 1 obtained PR, and only 1 is presently alive in CCR at 39 months after ABMT. Of the 17 children grafted in CR, 8 are alive event-free at 14-90 months (median 34) from ABMT; 7 relapsed at 3-23 months (median 7 months); 1 died of toxicity and 1 was lost to follow-up in CR at 12 months. A salvage attempt with high-dose chemotherapy in children with resistant or poor prognosis recurrent Wilms' tumor seems to be justified. An international cooperative protocol taking into account the increased risk of lung and renal toxicity is necessary.

High-dose chemotherapy with bone marrow rescue for treatment of Hodgkin's disease

Between December 1st 1984 and July 1st 1991, 20 patients, 11 males and 9 females, median age 36 years (range 14-54) with Hodgkin's disease were treated with high dose chemo-radiotherapy followed by autologous bone marrow rescue. At the time of autologous bone marrow transplantation, 8 patients were in complete remission, 9 in sensitive relapse and 3 were resistant to conventional treatments. There were 3 early procedure-related deaths: 1 cardiac failure due to cyclophosphamide treatment, 1 veno-occlusive disease, and 1 patient died from CMV interstitial pneumonitis, 4 months after ABMT. Of the 17 other patients, 15 are alive, 12 in complete remission, 2 in relapse and 1 patient is not evaluable due to short-follow-up follow-up. Disease free survival is 65% at 20 months with a follow-up of 60 months. There is a trend for a better disease-free survival in patients in complete remission at the time of autologous bone marrow transplantation vs patients in sensitive relapse, although it does not reach statistical significance (80% vs 37%).

[Treatment of resistant or relapsing Hodgkin's disease with high doses of chemotherapy followed by autologous bone marrow transplant]

Eleven patients with Hodgkin's disease were treated with high-dose chemotherapy followed by autologous bone marrow transplantation (ABMT). Four patients were resistant to initial therapy and 7 patients had relapsed but were progressing under second or third line therapy. The median time from initial diagnosis to transplantation was 44 months (range, 16 to 82). In 9 patients pre-ABMT consisted on high-dose CVB cyclophosphamide, etoposide and carmustine) chemotherapy, one patient was treated with BACT protocol (carmustine, cytosine arabinoside, cyclophosphamide and thioguanine) and other patient was treated with high-dose of busulfan and melphalan. In 8 patients complete remission (CR) was achieved, in one the remission was partial, one failed to respond and one case was not evaluable due to early death. Among CR patients, 2 died from late toxicity, and the other 6 remain in CR off therapy, one of them more than 33 months after ABMT. High-dose therapy produce severe myelosuppression in all patients. There were 3 treatment related death: one early death due to hemorrhagic myocarditis, one veno-occlusive disease of the liver and one due to cytomegalovirus sepsis. The high complete response rate in these heavily pretreated patients suggests that there may be an indication for high-dose therapy and ABMT in earlier resistant Hodgkin's disease. Moreover under such conditions, treatment related morbidity would be expected to be lower.

[Genitourinary rhabdomyosarcoma in childhood]

We present the result obtained by GICOP in the treatment of 12 genitourinary rhabdomyosarcoma, located in vagina-uterus (5), bladder-prostate (4) and paratesticular (3). The age of the patients ranging from 1 to 15 years. Embryonal rhabdomyosarcoma was the most common histologic type (58 for 100) being the major number of cases in stadium II. The treatment was based in the combination of chemotherapy protocolised with vincristine, d-actinomycin, cyclophosphamide (VAC), vincristine, adriamycin (VAC-VAD) and/or iphosphamide, vincristine, d-actinomycin (IVA), use of radiotherapy, marrow auto-transplantation and radical surgery avoidance. Complete remission was achieved in 11 out of 12 cases (92 for 100), relapsing in 5 cases (38 for 100) of which 4 (80 for 100) achieved a second remission. An 82 for 100 disease free survival was achieved in a 5 year period.