Inhibition of USP1 reverses the chemotherapy resistance through destabilization of MAX in the relapsed/refractory B-cell lymphoma.

The patients with relapsed and refractory diffuse large B-cell lymphoma (DLBCL) have poor prognosis, and a novel and effective therapeutic strategy for these patients is urgently needed. Although ubiquitin-specific protease 1 (USP1) plays a key role in cancer, the carcinogenic effect of USP1 in B-cell lymphoma remains elusive. Here we found that USP1 is highly expressed in DLBCL patients, and high expression of USP1 predicts poor prognosis. Knocking down USP1 or a specific inhibitor of USP1, pimozide, induced cell growth inhibition, cell cycle arrest and autophagy in DLBCL cells. Targeting USP1 by shRNA or pimozide significantly reduced tumor burden of a mouse model established with engraftment of rituximab/chemotherapy resistant DLBCL cells. Pimozide significantly retarded the growth of lymphoma in a DLBCL patient-derived xenograft (PDX) model. USP1 directly interacted with MAX, a MYC binding protein, and maintained the stability of MAX through deubiquitination, which promoted the transcription of MYC target genes. Moreover, pimozide showed a synergetic effect with etoposide, a chemotherapy drug, in cell and mouse models of rituximab/chemotherapy resistant DLBCL. Our study highlights the critical role of USP1 in the rituximab/chemotherapy resistance of DLBCL through deubiquitylating MAX, and provides a novel therapeutic strategy for rituximab/chemotherapy resistant DLBCL.

A retrospective analysis of real-world outcomes of elderly Chinese patients with diffuse large B-cell lymphoma.

BACKGROUND: Elderly patients with diffuse large B-cell lymphoma (DLBCL) have a worse prognosis than younger patients, and the optimal treatment strategy for this group remains controversial. We conducted a retrospective analysis to investigate the clinical features and outcomes of elderly patients (>60 years) and to assess the impact of clinical and molecular factors on outcome in this age group. METHODS: From April 2006 to December 2012, a total of 349 elderly patients with DLBCL from the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College were included in this analysis. Patients were further divided into two age groups (61-69 years and ≥70 years). We compared clinical characteristics and outcomes between groups. RESULTS: Of 349 total patients, 204 (58.5%) were aged 61 to 69 years, and 145 (41.5%) patients were aged 70 years or older. Except for the Eastern Cooperative Oncology Group performance status, clinical characteristics were comparable between the two groups. With a median follow-up of 82 (range, 1-129) months, the 5-year overall survival (OS) and progression-free survival (PFS) rates were 51.9% and 45.8%, respectively. The 5-year OS rates for patients aged 61 to 69 years and those over 70 years were 58.3% and 42.8% (P = 0.007), respectively, and the 5-year PFS rates were 51.0% and 38.6% (P = 0.034). Treatment regimens including rituximab provided a higher 5-year OS rate (63.1% vs. 37.1%, P < 0.001) and PFS rate (56.6% vs. 31.8%, P < 0.001) than chemotherapy alone. For patients aged 61 to 69 years, chemotherapy plus rituximab resulted in a higher 5-year OS rate (66.7% vs. 46.4%, P = 0.002) and PFS rate (60.0% vs. 38.1%, P = 0.002) than chemotherapy alone. For patients aged ≥70 years, there was a marked survival advantage in patients who received chemotherapy plus rituximab (5-year OS rate: 57.7% vs. 25.4%, P < 0.001; 5-year PFS rate: 51.3% vs. 23.9%, P < 0.001) compared with that seen in those who received chemotherapy alone. Multivariate analysis established that stage III/IV disease, elevated lactate dehydrogenase (LDH), initial treatment, and chemotherapy with rituximab were independent risk factors for 5-year OS, and stage III/IV disease, elevated LDH, and chemotherapy with rituximab were independent risk factors for 5-year PFS for elderly patients with DLBCL. CONCLUSIONS: In comparison to patients aged 61 to 69 years, those aged ≥70 years have poorer survival. Prolonged survival is obtainable with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)-like in elderly Chinese patients in all age groups, indicating that the R-CHOP-like regimen should be considered for this population, even for those aged 70 years or older.

iRNAm5C-PseDNC: identifying RNA 5-methylcytosine sites by incorporating physical-chemical properties into pseudo dinucleotide composition.

Occurring at cytosine (C) of RNA, 5-methylcytosine (m5C) is an important post-transcriptional modification (PTCM). The modification plays significant roles in biological processes by regulating RNA metabolism in both eukaryotes and prokaryotes. It may also, however, cause cancers and other major diseases. Given an uncharacterized RNA sequence that contains many C residues, can we identify which one of them can be of m5C modification, and which one cannot? It is no doubt a crucial problem, particularly with the explosive growth of RNA sequences in the postgenomic age. Unfortunately, so far no user-friendly web-server whatsoever has been developed to address such a problem. To meet the increasingly high demand from most experimental scientists working in the area of drug development, we have developed a new predictor called iRNAm5C-PseDNC by incorporating ten types of physical-chemical properties into pseudo dinucleotide composition via the auto/cross-covariance approach. Rigorous jackknife tests show that its anticipated accuracy is quite high. For most experimental scientists' convenience, a user-friendly web-server for the predictor has been provided at http://www.jci-bioinfo.cn/iRNAm5C-PseDNC along with a step-by-step user guide, by which users can easily obtain their desired results without the need to go through the complicated mathematical equations involved. It has not escaped our notice that the approach presented here can also be used to deal with many other problems in genome analysis.

Small-Cell Lung Cancer Transformation in Patients With Pulmonary Adenocarcinoma: A Case Report and Review of Literature.

Despite the demonstrated benefit from epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) based therapies, EGFR mutant lung adenocarcinoma will eventually acquire drug resistance. Transformation to small-cell lung cancer (SCLC) is considered to be a rare resistance mechanism of EGFR-TKI therapy.We describe a case of a 46-year-old man presenting with refractory cough. Percutaneous transthoracic biopsy was performed and confirmed an EGFR exon 21 L858R lung adenocarcinoma. However, the patient relapsed after successful treatment with gefitinib for 1 year, at which point rebiopsy identified an SCLC and chemotherapy composed of platinum and pemetrexed was started. However, despite the brief success of chemotherapy, our patient died of aggressive cancer progression and complications of chemotherapy.Our case highlights the importance of rebiopsy when managing drug resistance and presents a possible origin of the transformed cells. We also summarize the clinical characteristics of cases involving transformed SCLC from previous studies and discuss whether it could be a new subtype of SCLC.