Jin Ho Paik

MicroRNA-146a Downregulates NFκB Activity via Targeting TRAF6 and Functions as a Tumor Suppressor Having Strong Prognostic Implications in NK/T Cell Lymphoma

Purpose: We investigated prognostic implications of microRNAs in extranodal NK/T cell lymphoma (NKTL). Experimental Design: We measured miRNA expression in NKTL tissues and cell lines, using real-time PCR, and analyzed its role in NKTL, using cell lines. Results: Multivariate analysis showed low miR-146a expression (P < 0.001; HR = 13.110), primary non–upper aerodigestive tract lesion (non-UAT; P = 0.008; HR = 5.376) and high International Prognostic Index (IPI; ≥3; P = 0.013; HR = 3.584) to be independent poor prognostic factors. miR-146a expression could subdivide UAT-NKTL into 2 prognostic groups, resulting in the following prognostic groups: (i) UATLow-146a, (ii) UATHigh-146a, and (iii) non-UAT. Compared with UATHigh-146a, UATLow-146a showed distinctively poor prognosis (P < 0.001; HR = 15.620), similar to the non-UAT group. In vitro, miR-146a overexpression in NKTL cell lines, SNK6 and YT, inhibited nuclear factor κB (NFκB) activity, suppressed cell proliferation, induced apoptosis, and enhanced chemosensitivity. TNF receptor–associated factor 6, a target of miR-146a and a known NFκB activator, was downregulated by miR-146a in SNK6 and YT cells. Promoter methylation of miR-146a gene was observed in SNK6 and YT cells, as well as in NKTL tissues with low miR-146a expression, and miR-146a expression was induced by the conversion of methylation status with a demethylating agent in SNK6 and YT cells. Conclusions: These results suggest that miR-146a might function as a potent tumor suppressor in NKTL and be useful for patient assessment and therapeutic targeting. Clin Cancer Res; 17(14); 4761–71. ©2011 AACR.

Resveratrol induces the suppression of tumor-derived CD4+CD25+ regulatory T cells

CD4+CD25+ regulatory T cells (Treg cells) are negative regulator of the immune system and main obstacles to cancer immunotherapy in tumor-bearing hosts. Resveratrol is a natural product found in grapes with both immunomodulatory and anticancer effects, which can be controlled by Treg cells. Therefore, to determine whether resveratrol performs these actions via Treg cells, we investigated changes in Treg cell population and immunomodulatory cytokines in EG7 tumor-bearing C57BL/6 mice. In the present study, CD4+CD25+ cell population among CD4+ cells was inhibited ex vivo by resveratrol treatment in a dose-dependent manner. FoxP3+ expressing cells among CD4+CD25+ population were significantly reduced after resveratrol treatment ex vivo in intracellular FACS analysis. Single intraperitoneal administration of 4 mg/kg resveratrol suppressed the CD4+CD25+ cell population among CD4+ cells and downregulated secretion of TGF-beta, an immunosuppressive cytokine, measured from the spleens of tumor-bearing mice. Furthermore, resveratrol enhanced IFN-gamma expression in CD8+ T cells both ex vivo and in vivo,leading to immune stimulation. Taken together, these results suggest that resveratrol has a suppressive role on CD4+CD25+ cell population and makes peritumoral microenvironment unfavorable to tumor in tumor-bearing mice. Thus, resveratrol can be considered as possible adjuvant material for vaccination-based cancer therapy.

Overexpression of sphingosine-1-phosphate receptor 1 and phospho-signal transducer and activator of transcription 3 is associated with poor prognosis in rituximab-treated diffuse large B-cell lymphomas

BackgroundSphingosine-1-phosphate receptor-1 (S1PR1) and signal transducer and activator of transcription-3 (STAT3) play important roles in immune responses with potential oncogenic roles.MethodsWe analyzed S1PR1/STAT3 pathway activation using immunohistochemistry in rituximab-treated diffuse large B-cell lymphomas (DLBCL; N =u2009103).ResultsNuclear expression of pSTAT3 (but not S1PR1) was associated with non-GCB phenotype (p =u20090.010). In univariate survival analysis, S1PR1 expression (S1PR1+) was a poor prognostic factor in total DLBCLs (p =u20090.018), as well as in nodal (p =u20090.041), high-stage (III, IV) (p =u20090.002), and high-international prognostic index (IPI; 3–5) (p =u20090.014) subgroups, while nuclear expression of pSTAT3 (pSTAT3+) was associated with poor prognosis in the low-stage (I, II) subgroup (p =u20090.022). The S1PR1/pSTAT3 risk-categories, containing high-risk (S1PR1+), intermediate-risk (S1PR1-/pSTAT3+), and low-risk (S1PR1-/pSTAT3-), predicted overall survival (p =u20090.010). This prognostication tended to be valid in each stage (p =u20090.059 in low-stage; p =u20090.006 in high-stage) and each IPI subgroups (p =u20090.055 [low-IPI]; p =u20090.034 [high-IPI]). S1PR1 alone and S1PR1/pSTAT3 risk-category were significant independent prognostic indicators in multivariate analyses incorporating IPI and B symptoms (S1PR1 [p =u20090.005; HR =u20093.0]; S1PR1/pSTAT3 risk-category [p =u20090.019: overall; p =u20090.024, HR =u20092.7 for S1PR1-/pSTAT3+ vs. S1PR1+; p =u20090.021, HR =u20093.8 for S1PR1-/pSTAT3- vs. S1PR1+]).ConclusionsTherefore, S1PR1 and S1PR1/pSTAT3 risk-category may contribute to risk stratification in rituximab-treated DLBCLs, and S1PR1 and STAT3 might be therapeutic targets for DLBCL.

Class III β-Tubulin Shows Unique Expression Patterns in a Variety of Neoplastic and Non-neoplastic Lymphoproliferative Disorders:

Class III β-tubulin (TUBB3) expression in carcinoma is associated with resistance to tubulin-binding chemotherapeutic agents. Recently, follicular dendritic cells (FDCs) were reported to express TUBB3 under physiologic conditions. We investigated TUBB3 expression in a wide range of lymphoproliferative disorders using immunohistochemistry. Dual immunostaining for Bcl-6 and TUBB3 revealed that some germinal center B cells also express TUBB3 in addition to FDCs. In Hodgkin lymphomas (HLs), 47.1% (40/85) expressed TUBB3 in the tumor cells with an all-or-none pattern. TUBB3 expression in HL was more common in mixed cellularity type than nodular sclerosis type (P=0.032). Among non-HLs, 79.3% (23/29) of anaplastic large cell lymphoma (ALCL), 8% (2/25) of extranodal natural killer/T-cell lymphoma, and 75% (21/28) of Burkitt lymphoma showed TUBB3 expression with an all-or-none pattern. Of diffuse large B-cell lymphoma, 15.2% (32/210) expressed TUBB3 in a heterogeneous pattern. In ALCL, TUBB3 expression was more common in systemic ALCL than in primary cutaneous ALCL (P=0.046). Diffuse large B-cell lymphomas with a germinal center B-like subgroup exhibited TUBB3 expression more frequently than non−GCB-like subgroup (P=0.01). Otherwise, none of the 18 angioimmunoblastic T-cell lymphomas; 18 peripheral T-cell lymphomas, not otherwise specified; 12 follicular lymphomas; 62 marginal zone lymphomas; 7 mantle cell lymphomas; 8 small lymphocytic lymphomas; or 2 FDC sarcomas expressed TUBB3. In angioimmunoblastic T-cell lymphoma and Castleman disease, TUBB3 was positive in immunoblasts corresponding to Epstein-Barr virus-infected or Kaposi sarcoma herpes virus-infected cells. A variety of neoplastic and non-neoplastic lymphoproliferative disorders exhibited characteristic TUBB3 expression patterns; these results suggest potential for diagnostic utility, some insight into the pathobiology of TUBB3 expression, and potential therapeutic implications.

An autopsy case of aggressive CD30+ extra-nodal NK/T-cell lymphoma initially manifested with granulomatous myositis.

This study reports an autopsy case of a 53 year-old male with rapidly progressive extra-nodal NK/T-cell lymphoma accompanied with unusual clinical and pathologic features. He was initially presented with localized swelling and tenderness in the right lower extremity and the biopsy from the calf muscle was interpreted as granulomatous myositis masquerizing lymphoma. The biopsy from erythematous skin lesion of trunk showed infiltration of medium sized atypical lymphoid cells with relatively plump cytoplasm and immunophenotype of CD30+, CD56+/− and surface CD3−, which lead to the diagnosis of CD30+ anaplastic large cell lymphoma. About 2 months later, nasal obstruction was developed and the nasal biopsy was done. After confirmation of EBV infection, he was finally diagnosed as extra-nodal NK/T-cell lymphoma with peculiar immunophenotype of CD3ϵ dim+ and CD30+. Despite the chemotherapy, he was going rapidly downhill and died of respiratory and multi-organ failure 8 months after the onset of soft tissue lesion. At autopsy, disseminated angiocentric lymphoma was found all over the internal organs including the brain. This case emphasizes that extra-nodal NK/T-cell lymphoma should be considered as a cause of granulomatous myositis and can express CD30 positivity and CD3ϵ weak positivity, which are unusual but rarely predominant feature of NK/T-cell lymphoma.

Teaching NeuroImages: Superior divisional oculomotor nerve palsy due to orbital lymphoma

Divisional patterns of oculomotor nerve palsy usually indicate a lesion involving the oculomotor nerve distal to anterior cavernous sinus where the nerve divides into the superior and inferior branches.1 A 48-year-old man showed painless ptosis and limitation of elevation, but normal pupil in the left eye (figure, A), which indicates a lesion limited to the oculomotor superior division that innervates the levator palpebrae and superior rectus. MRI revealed a nonpalpable mass in the superior portion of left orbital cavity (figure, B) that was confirmed as a malignant lymphoma (figure, C). Orbital lesions including lymphoma should be considered in divisional patterns of oculomotor palsy.2

Clinicopathologic implication of microRNA-197 in diffuse large B cell lymphoma

BackgroundDiffuse large B cell lymphoma (DLBCL) contains heterogeneous subtypes with various molecular dysregulation at the gene, protein and microRNA levels. Compared with the GCB subtype, the non-germinal center B-like (non-GCB)/activated B cell-like (ABC) subtype exhibits frequent progression despite standard immunochemotherapy. We aimed to investigate the effects of miR-197 on the progression and chemosensitivity of DLBCL with respect to the GCB and non-GCB/ABC subtypes.MethodsTo screen distinctively expressed microRNAs, microRNA expression patterns were analyzed in 10 DLBCL cases by microarray chip assays. Using quantitative real-time polymerase chain reaction (qRT-PCR), associations between miR-197 expression levels and clinicopathologic variables were investigated in 51 DLBCL tissue samples. The effects of miR-197 on doxorubicin chemosensitivity were investigated using the OCI-Ly1 and SUDHL9 cell lines.ResultsMicroRNA expression profiling by hierarchical clustering revealed that miR-197 was one of the distinctively expressed microRNAs in DLBCL. Quantitative analysis using qRT-PCR revealed that miR-197 levels were not correlated with clinicopathologic variables, including the international prognostic index, but low miR-197 levels were significantly associated with lymphoma progression defined by refractoriness, relapse or death in the rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)-treated subgroup (nu2009=u200943; pu2009=u20090.004). Among the three molecular groups, i.e., the GCB, non-GCB/miR-197low and non-GCB/miR-197high groups, progression was most frequently observed in the non-GCB/miR-197low group in the full cohort (pu2009=u20090.013) and the R-CHOP cohort (pu2009=u20090.008). In survival analysis, low miR-197 levels were independently predictive of shorter progression-free survival in the R-CHOP cohort (pu2009=u20090.031; HRu2009=u200927.9) and the non-GCB subgroup (pu2009=u20090.037; HRu2009=u200921.5) but not in the GCB subgroup. Using SUDHL9 (ABC type) and OCI-Ly1 (GCB type) cells, the effects of doxorubicin on reducing cell viability were enhanced by miR-197 transfection. In apoptosis assays, miR-197 transfection enhanced doxorubicin-induced apoptosis in SUDHL9 cells but not in OCI-Ly1 cells, suggesting a chemosensitizing effect of miR-197 in ABC DLBCL.ConclusionsThese results suggest the role of miR-197 as a biomarker with potential therapeutic implications.

In Vivo Scintigraphic Imaging of Antitumor Effects by Combined Radioiodine Therapy and Human Sodium Iodide Symporter Gene Immunotherapy

In a previous study, we demonstrated that pcDNA3.1/hNIS (human sodium iodide symporter) vaccination generated hNIS-associated CD8+IFN-γ+ (interferon-γ) T cells, which are known to be involved in antitumor immunity. However, the immune response induced was insufficient to control tumor growth in vivo, which required a novel approach to potentiate hNIS vaccination effects. In the present study, we administered 131II radioiodine therapy prior to hNIS vaccination in CT26/hNIS tumor-bearing mice to facilitate the vaccine-induced immune response. We characterized hNIS-associated cytotoxic T-cell immune response and the antitumor effects induced by this 131II + hNIS combination therapy. The survival rates of CT26/hNIS tumor cells were significantly reduced by 131II treatment compared with the parental CT26 cells in vitro. 131II + hNIS combination therapy stably suppressed tumor growth below or near the original tumor size level of initial treatment, achieving 100% survival rates. Specifically, 131II + hNIS therapy enhanced IFN-γ production, hNIS-associated antitumor cytotoxic T-lymphocyte (CTL) response, and induced more dendritic cells but reduced T-regulatory cells in tumor masses. Collectively, these results suggest that combined therapy effectively enhances hNIS-associated antitumor immune response, leading to CT26/hNIS tumor growth inhibition and complete survival in Balb/C mice. These findings provide a novel and effective means of treating cancer.