Regulation of Krüppel-Like Factor 4 (KLF4) expression through the transcription factor Yin-Yang 1 (YY1) in non-Hodgkin B-cell lymphoma.

Krüppel-Like Factor 4 (KLF4) is a member of the KLF transcription factor family, and evidence suggests that KLF4 is either an oncogene or a tumor suppressor. The regulatory mechanism underlying KLF4 expression in cancer, and specifically in lymphoma, is still not understood. Bioinformatics analysis revealed two YY1 putative binding sites in the KLF4 promoter region (-950 bp and -105 bp). Here, the potential regulation of KLF4 by YY1 in NHL was analyzed. Mutation of the putative YY1 binding sites in a previously reported system containing the KLF4 promoter region and CHIP analysis confirmed that these binding sites are important for KLF4 regulation. B-NHL cell lines showed that both KLF4 and YY1 are co-expressed, and transfection with siRNA-YY1 resulted in significant inhibition of KLF4. The clinical implications of YY1 in the transcriptional regulation of KLF4 were investigated by IHC in a TMA with 43 samples of subtypes DLBCL and FL, and all tumor tissues expressing YY1 demonstrated a correlation with KLF4 expression, which was consistent with bioinformatics analyses in several databases. Our findings demonstrated that KLF4 can be transcriptionally regulated by YY1 in B-NHL, and a correlation between YY1 expression and KLF4 was found in clinical samples. Hence, both YY1 and KLF4 may be possible therapeutic biomarkers of NHL.

Predicting Human miRNA-like Sequences within Human Papillomavirus Genomes.

BACKGROUND: This study presents a prediction of putative miRNA within several Human Papillomavirus (HPV) types by using bioinformatics tools and a strategy based on sequence and structure alignment. Currently, little is known about HPV miRNAs. METHODS: Computational methods have been widely applied in the identification of novel miRNAs when analyzing genome sequences. Here, ten whole-genome sequences from HPV-6, -11, -16, -18, -31, -33, -35, -45, -52, and -58 were analyzed. Software based on local contiguous structure-sequence features and support vector machine (SVM), as well as additional bioinformatics tools, were utilized for identification and classification of real and pseudo microRNA precursors. RESULTS: An initial analysis predicted 200 putative pre-miRNAs for all the ten HPV genome variants. To derive a smaller set of pre-miRNAs candidates, stringent validation criteria was conducted by applying <‒10 ΔG value (Gibbs Free Energy). Thus, only pre-miRNAs with total scores above the cut-off points of 90% were considered as putative pre-miRNAs. As a result of this strategy, 19 pre-miRNAs were selected (hpv-pre-miRNAs). These novel pre-miRNAs were located in different clusters within HPV genomes and some of them were positioned at splice regions. Additionally, the 19 identified pre-miRNAs sequences varied between HPV genotypes. Interestingly, the newly identified miRNAs, 297, 27b, 500, 501-5, and 509-3-5p, were closely implicated in carcinogenesis participating in cellular longevity, cell cycle, metastasis, apoptosis evasion, tissue invasion and cellular growth pathways. CONCLUSIONS: The novel putative miRNAs candidates could be promising biomarkers of HPV infection and furthermore, could be targeted for potential therapeutic interventions in HPV-induced malignancies.

Rituximab in the treatment of diffuse large B-cell lymphoma primary of the lung.

Diffuse large B-cell lymphoma primary of lung (DLBCL-PL) is a rare presentation of extranodal lymphoma, in most cases chemotherapy-based anthracyclines: CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) has been the treatment, with excellent outcome. The addition of rituximab to CHOP (R-CHOP) has been considered the gold standard in the treatment of nodal DLBCL. Thus, we assess in a large number of cases of DLBCL-PL whether the use of R-CHOP could improve survival in this setting of patients. Forty-two patients with DLBCL-PL, stage IE, age 65 years or younger, were treated with standard R-CHOP, no consolidation radiotherapy or maintenance therapy were considered. They were matched with patients who received CHOP alone to assess efficacy and toxicity. Complete response was observed in 35 patients (83%), and 7 patients were considered failure (16%). The study has a median follow-up of 42.8 months. Actuarial curves at 5 years showed that progression-free survival was 88 % and overall survival was 70 %. The results were not statistically different when compared retrospectively with patients who received CHOP alone. Treatment was well tolerated. The addition of rituximab to chemotherapy did not improve outcome in patients with DLBCL-PL.

Randomized clinical trial to assess the efficacy of radiotherapy in primary mediastinal large B-lymphoma.

PURPOSE: We developed a controlled clinical trial to assess the efficacy and toxicity of adjuvant-involved field radiotherapy (IFRT) in patients with primary mediastinal B-cell lymphoma that achieved complete response after the patients were treated with cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab (R-CHOP-14). METHODS AND MATERIALS: Between January 2001 and June 2004, 124 consecutive patients who were in complete remission after dose dense chemotherapy and rituximab administration (R-CHOP14) were randomly assigned to received IFRT (30 Gy). Sixty-three patients received IFR, and 61 patients did not (control group). RESULTS: The study aimed to include 182 patients in each arm but was closed prematurely because in a security analysis (June 2004), progression and early relapse were more frequent in patients that did not received IFRT. Patients were followed until March 2009, at which point actuarial curves at 10 years showed that progression free-survival was 72% in patients who received IFR and 20% in the control group (p < 0.001), overall survival was 72% and 31%, respectively (p < 0.001). Acute toxicity was mild and well tolerated. DISCUSSION: Adjuvant radiotherapy to sites of bulky disease was the only difference to have an improvement in outcome in our patients; the use of rituximab during induction did not improve complete response rates and did affect overall survival; patients who received rituximab but not IFRT had a worse prognosis. CONCLUSIONS: The use of IFRT in patients with primary mediastinal B-cell lymphoma who achieved complete response remain as the best treatment available, even in patients that received rituximab during induction.

Antitumor effect of zoledronic acid in previously untreated patients with multiple myeloma.

Bisphophonates are the treatment of choice to prevent skeletal events in patients with multiple myeloma. Some preclinical studies suggested that bisphophonates can be useful as antitumor drugs in some malignancies. We conducted a controlled clinical trial to assess if zoledronic acid can have this clinical activity. Ninety four patients with previously untreated multiple myeloma were treated with a conventional chemotherapy program: cyclophosphamide, vincristine, melphalan, and prednisone (CVMP) and were randomized to received either zoledronic acid (4 mg, iv, every 28 d) or not (control group). The end-point of the present study was to assess improvement in outcome, measured by event-free survival (EFS) and overall survival (OS), and the second-end point was to confirm the efficacy in preventing skeletal events. In an intent-to-treat analysis, all patients were available for efficacy and toxicity. Median follow up was 49.6 mo (range: 34-72 mo). Five year actuarial curves showed that EFS was 80% in the zoledronic acid group, which was statistically different from 52% in the control group (p < 0.01). Actuarial 5 yr OS was 80% in the zoledronic acid arm, and 46% in the control group (p < 0.01). Sketeletal events were more frequent in the control group when compared to zoledronic acid. Toxicity was mild. We confirm the efficacy of zoledronic acid to prevent skeletal events, but we felt that we can demonstrate that zoledronic acid has a clinical antitumor effect measured from a increase in complete response rate and EFS and OS that were better when compared with the control group. We began a controlled clinical trial with modern treatment (including transplant procedures) in combination with zoledronic acid to define the role of zoledonic acid in this setting of patients.

Dose dense (CEOP-14) vs dose dense and rituximab (CEOP-14 +R) in high-risk diffuse large cell lymphoma.

To assess efficacy and toxicity of rituximab and dose chemotherapy in high-risk diffuse large cell lymphoma, we conducted a controlled clinical trial to assess efficacy and toxicity of a dose-dense regimen CEOP- 14 (cyclophosphamide, epirubicin, vincristine, and prednisone every 14 d) compared to CEOP-14 plus rituximab. One hundred and ninety-six patients were randomized to received CEOP-rituximab (cyclophosphamide 1500 mg/m2, epirubicin 120 mg/m2, vincristine, and prednisone at standard dose and rituximab at 375 mg/m2) compared with the same chemotherapy administered every 14 d (CEOP-14). In an intent-to-treat analysis all patients were available for efficacy and toxicity. Complete response in CEOP-14 was observed in 73 cases (74%) and in 75 patients (76%) in the CEOP-R regimen (76%) (p = 0.8). With a median follow-up of 53.4 mo, median has not been reached in time to tumor-progression (TTP) and overall survival (OS). Actuarial curves at 5 yr showed that TTP and OS in patients treated with CEOP-R were 74% and 67%, respectively, that were not statistical different when compared to CEOP-14, 72% and 65%, respectively (p = 0.8). Acute toxicity was mild and well tolerated. The use of a dense-dose regimen is useful and well tolerated in patients with very high risk diffuse large cell lymphoma. The addition of rituximab did not improve outcome in these setting of patients.