Low absolute peripheral blood CD4+ T-cell count predicts poor prognosis in R-CHOP-treated patients with diffuse large B-cell lymphoma.

The absolute peripheral blood lymphocyte count at diagnosis is known to be a strong prognostic factor in patients with diffuse large B-cell lymphoma (DLBCL) treated with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP), but it remains unclear as to which peripheral blood lymphocyte population is reflective of DLBCL prognosis. In this cohort, 355 patients with DLBCL treated with R-CHOP from 2006 to 2013 were analyzed. The low absolute CD4+ T-cell count (ACD4C) at diagnosis negatively correlated with the overall response rate and the complete response rate significantly (P<0.00001). An ACD4C<343 × 106/l had a significant negative impact on the 5-year progression-free survival and the overall survival as compared with an ACD4C⩾343 × 106/l (73.7% (95% confidence interval (CI)=66.7-79.5) versus 50.3% (95% CI=39.0-60.6), P<0.00001 and 83.3% (95% CI=77.1-88.0) versus 59.0% (95% CI=47.9-68.5), P<0.00000001, respectively). Multivariate analysis revealed that the ACD4C was an independent prognostic marker (hazard ratio=2.2 (95% CI=1.3-3.7), P<0.01). In conclusion, a low ACD4C at diagnosis served as an independent poor prognostic marker in patients with DLBCL.

Proteomic characterization of human multiple myeloma bone marrow extracellular matrix.

The extracellular matrix (ECM) is a major component of the tumor microenvironment, contributing to the regulation of cell survival, proliferation, differentiation and metastasis. In multiple myeloma (MM), interactions between MM cells and the bone marrow (BM) microenvironment, including the BM ECM, are critical to the pathogenesis of the disease and the development of drug resistance. Nevertheless, composition of the ECM in MM and its role in supporting MM pathogenesis has not been reported. We have applied a novel proteomic-based strategy and defined the BM ECM composition in patients with monoclonal gammopathy of undetermined significance (MGUS), newly diagnosed and relapsed MM compared with healthy donor-derived BM ECM. In this study, we show that the tumor ECM is remodeled at the mRNA and protein levels in MGUS and MM to allow development of a permissive microenvironment. We further demonstrate that two ECM-affiliated proteins, ANXA2 and LGALS1, are more abundant in MM and high expression is associated with a decreased overall survival. This study points to the importance of ECM remodeling in MM and provides a novel proteomic pipeline for interrogating the role of the ECM in cancers with BM tropism.

The LIN28B/let-7 axis is a novel therapeutic pathway in multiple myeloma.

MYC is a major oncogenic driver of multiple myeloma (MM) and yet almost no therapeutic agents exist that target MYC in MM. Here we report that the let-7 biogenesis inhibitor LIN28B correlates with MYC expression in MM and is associated with adverse outcome. We also demonstrate that the LIN28B/let-7 axis modulates the expression of MYC, itself a let-7 target. Further, perturbation of the axis regulates the proliferation of MM cells in vivo in a xenograft tumor model. RNA-sequencing and gene set enrichment analyses of CRISPR-engineered cells further suggest that the LIN28/let-7 axis regulates MYC and cell cycle pathways in MM. We provide proof of principle for therapeutic regulation of MYC through let-7 with an LNA-GapmeR (locked nucleic acid-GapmeR) containing a let-7b mimic in vivo, demonstrating that high levels of let-7 expression repress tumor growth by regulating MYC expression. These findings reveal a novel mechanism of therapeutic targeting of MYC through the LIN28B/let-7 axis in MM that may impact other MYC-dependent cancers as well.

Targeting vasculogenesis to prevent progression in multiple myeloma.

The role of endothelial progenitor cell (EPC)-mediated vasculogenesis in hematological malignancies is not well explored. Here, we showed that EPCs are mobilized from the bone marrow (BM) to the peripheral blood at early stages of multiple myeloma (MM); and recruited to MM cell-colonized BM niches. Using EPC-defective ID1+/- ID3-/- mice, we found that MM tumor progression is dependent on EPC trafficking. By performing RNA-sequencing studies, we confirmed that endothelial cells can enhance proliferation and favor cell-cycle progression only in MM clones that are smoldering-like and have dependency on endothelial cells for tumor growth. We further confirmed that angiogenic dependency occurs early and not late during tumor progression in MM. By using a VEGFR2 antibody with anti-vasculogenic activity, we demonstrated that early targeting of EPCs delays tumor progression, while using the same agent at late stages of tumor progression is ineffective. Thus, although there is significant angiogenesis in myeloma, the dependency of the tumor cells on EPCs and vasculogenesis may actually precede this step. Manipulating vasculogenesis at an early stage of disease may be examined in clinical trials in patients with smoldering MM, and other hematological malignancies with precursor conditions.

A novel Bruton's tyrosine kinase inhibitor CC-292 in combination with the proteasome inhibitor carfilzomib impacts the bone microenvironment in a multiple myeloma model with resultant antimyeloma activity.

Bruton's tyrosine kinase (Btk) modulates B-cell development and activation and has an important role in antibody production. Interestingly, Btk may also affect human osteoclast (OC) function; however, the mechanism was unknown. Here we studied a potent and specific Btk inhibitor, CC-292, in multiple myeloma (MM). In this report, we demonstrate that, although CC-292 increased OC differentiation, it inhibited OC function via inhibition of c-Src, Pyk2 and cortactin, all involved in OC-sealing zone formation. As CC-292 did not show potent in vitro anti-MM activity, we next evaluated it in combination with the proteasome inhibitor, carfilzomib. We first studied the effect of carfilzomib on OC. Carfilzomib did not have an impact on OC-sealing zone formation but significantly inhibited OC differentiation. CC-292 combined with carfilzomib inhibited both sealing zone formation and OC differentiation, resulting in more profound inhibition of OC function than carfilzomib alone. Moreover, the combination treatment in an in vivo MM mouse model inhibited tumor burden compared with CC-292 alone; it also increased bone volume compared with carfilzomib alone. These results suggest that CC-292 combined with carfilzomib augments the inhibitory effects against OC within the bone microenvironment and has promising therapeutic potential for the treatment of MM and related bone disease.

Small-molecule multi-targeted kinase inhibitor RGB-286638 triggers P53-dependent and -independent anti-multiple myeloma activity through inhibition of transcriptional CDKs.

Small-molecule multi-targeted cyclin-dependent kinase (CDK) inhibitors (CDKIs) are of particular interest due to their potent antitumor activity independent of p53 gene alterations. P53 deletion is associated with a very poor prognosis in multiple myeloma (MM). In this regard, we tested the anti-MM activity of RGB-286638, an indenopyrazole-derived CDKI with Ki-nanomolar activity against transcriptional CDKs. We examined RGB-286638's mode-of-action in MM cell lines with wild-type (wt)-p53 and those expressing mutant p53. RGB-286638 treatment resulted in MM cytotoxicity in vitro associated with inhibition of MM tumor growth and prolonged survival in vivo. RGB-286638 displayed caspase-dependent apoptosis in both wt-p53 and mutant-p53 cells that was closely associated with the downregulation of RNA polymerase II phosphorylation and inhibition of transcription. RGB-286638 triggered p53 accumulation via nucleolar stress and loss of Mdm2, accompanied by induction of p53 DNA-binding activity. In addition, RGB-286638 mediated p53-independent activity, which was confirmed by cytotoxicity in p53-knockdown and p53-mutant cells. We also demonstrated downregulation of oncogenic miR-19, miR-92a-1 and miR-21. Our data provide the rationale for the development of transcriptional CDKIs as therapeutic agents, which activate p53 in competent cells, while circumventing p53 deficiency through alternative p53-independent cell death mechanisms in p53-mutant/deleted cells.

The identification of irreversible rituximab-resistant lymphoma caused by CD20 gene mutations.

C-terminal mutations of CD20 constitute part of the mechanisms that resist rituximab therapy. Most CD20 having a C-terminal mutation was not recognized by L26 antibody. As the exact epitope of L26 has not been determined, expression and localization of mutated CD20 have not been completely elucidated. In this study, we revealed that the binding site of L26 monoclonal antibody is located in the C-terminal cytoplasmic region of CD20 molecule, which was often lost in mutated CD20 molecules. This indicates that it is difficult to distinguish the mutation of CD20 from under expression of the CD20 protein. To detect comprehensive CD20 molecules including the resistant mutants, we developed a novel monoclonal antibody that recognizes the N-terminal cytoplasm region of CD20 molecule. We screened L26-negative cases with our antibody and found several mutations. A rituximab-binding analysis using the cryopreserved specimen that mutation was identified in CD20 molecules indicated that the C-terminal region of CD20 undertakes a critical role in presentation of the large loop in which the rituximab-binding site locates. Thus, combination of antibodies of two kinds of epitope permits the identification of C-terminal CD20 mutations associated with irreversible resistance to rituximab and may help the decision of the treatment strategy.

Down-regulation of single immunoglobulin interleukin-1R-related molecule (SIGIRR)/TIR8 expression in intestinal epithelial cells during inflammation.

Single immunoglobulin (Ig) interleukin-1R-related molecule (SIGIRR) is an Ig-like membrane protein critical for negative regulation of Toll-like receptor (TLR)-4-mediated signalling. We investigated SIGIRR expression and its regulation mechanism in intestinal epithelial cells (IECs) during inflammation. Endoscopic biopsy specimens were obtained from active and inactive colonic mucosa of ulcerative colitis (UC) patients, then SIGIRR expression was examined using real-time polymerase chain reaction (PCR) and immunohistochemistry (IH). Mice experimental colitis models were established by administrations of sulphonic acid (TNBS) and dextran sodium sulphate (DSS), and epithelial expression of SIGIRR was examined using real-time PCR, IH and flow cytometry. The effects of lipopolysaccharide (LPS) and tumour necrosis factor (TNF)-α on SIGIRR expression were evaluated in vitro using cultured IECs. To elucidate SIGIRR expression regulation in IECs, binding ability of the transcription factor SP1 at the responsive element of the SIGIRR promoter was examined using gel-shift and chromatin immunoprecipitation (ChIP) assays. In human colonic samples, SIGIRR was expressed mainly in IECs at levels significantly higher in inactive compared to active mucosa. In the mice, SIGIRR colonic expression decreased rapidly after colitis development and returned gradually to basal levels. Experimental colitis-mediated down-regulation of SIGIRR in IECs was also confirmed by IH and flow cytometry results. Further, inflammatory conditions induced by TLR ligands and TNF-α caused significant down-regulation of SIGIRR expression in IECs, which was dependent upon decreased SP1 binding at the responsive element of the SIGIRR promoter. We found that SIGIRR is expressed in IECs and serves as a negative regulator to maintain gut innate immunity, which is down-regulated during inflammation by inhibition of an SP1-mediated pathway.

A20 is an early responding negative regulator of Toll-like receptor 5 signalling in intestinal epithelial cells during inflammation.

Several negative regulatory mechanisms control Toll-like receptor (TLR)-mediated inflammatory responses and restore immune system balance, including the zinc-finger protein A20, a negative regulator of TLR signalling that inhibits nuclear factor kappa B (NF-kappaB) activity. In the present study, we investigated TLR-5-mediated A20 expression and its role in intestinal epithelial cells (IECs) during inflammation. HCT-15 and HT-29 cells were stimulated with flagellin, then the expressions of A20, interleukin-1 receptor-associated kinase (IRAK-M) and Tollip were evaluated using RNase protection assay. Furthermore, experimental colitis was induced in tlr4-deficient CH3/HeJ mice by administration of dextran sodium sulphate (DSS), then flagellin was injected anally, and the colonic expression of A20 was examined by real-time polymerase chain reaction (PCR) and immunohistochemistry. To confirm flagellin-induced expression of A20, we employed an organ culture system. The role of A20 in flagellin-induced tolerance induction was evaluated in vitro, using a gene knock-down method targeting A20. A20 expression increased rapidly and peaked at 1 h after flagellin stimulation in cultured IECs, then declined gradually to the basal level. In vivo, anal injection of flagellin induced epithelial expression of A20 in injured colonic tissue, whereas flagellin did not cause a significant increase in A20 expression in non-injured normal tissue, which was also confirmed in vitro using the organ culture system. Gene knock-down using A20 siRNA did not influence tolerance induced by restimulation with flagellin. A20 is an early response negative regulator of TLR-5 signalling in IECs that functions during intestinal inflammation. Our results provide new insights into the negative feedback regulation of TLR-5 signalling that maintains the innate immune system in the gut.

Bone metastasis and poor performance status are prognostic factors for survival of carcinoma of unknown primary site in patients treated with systematic chemotherapy.

BACKGROUND: Cancer of unknown primary site (CUP) generally has a poor prognosis, and there is no established standard therapy. There have been no reports of a prognostic model for CUP patients treated with a single regimen of systemic chemotherapy. METHODS: Univariate and multivariate prognostic factor analysis for overall survival (OS) were conducted retrospectively in 58 consecutive CUP patients treated with carboplatin plus paclitaxel (Taxol) therapy as a first-line treatment. RESULTS: Univariate prognostic factor analysis revealed baseline performance status (PS) of two or more, low serum albumin level, pleural effusion, bone metastasis, and liver metastasis as adverse prognostic factors. Cox proportional hazards analysis showed that poor PS and bone metastasis had the most powerful adverse impact on survival. We developed a prognostic model using those two variables-a good-risk group (PS 0-1 without bone metastasis) and a poor-risk group (PS > or =2 or bone metastasis). The poor-risk group showed significantly poorer OS than the good-risk group (1 year OS 36.8% versus 67.1%, P = 0.0003). CONCLUSIONS: Poor PS and bone metastasis were identified as independent adverse prognostic factors in CUP. A simple prognostic model was developed and seems useful for decision making as to whether chemotherapy is indicated for CUP patients.

Soluble interleukin-2 receptor retains prognostic value in patients with diffuse large B-cell lymphoma receiving rituximab plus CHOP (RCHOP) therapy.

BACKGROUND: Soluble interleukin-2 receptor (SIL-2R) is known to be a prognostic parameter in patients with diffuse large B-cell lymphoma (DLBCL) receiving cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) therapy. However, its prognostic value has not been well known since the introduction of rituximab. PATIENTS AND METHODS: We retrospectively evaluated the prognostic impact of SIL-2R in 228 DLBCL patients, comparing 141 rituximab-combined CHOP (RCHOP)-treated patients with 87 CHOP-treated patients as a historical control. RESULTS: Patients with high serum SIL-2R showed significantly poorer event-free survival (EFS) and overall survival (OS) than patients with low SIL-2R in both the RCHOP group (2-year EFS, 66% versus 92%, P<0.001; OS, 82% versus 95%, P=0.005) and the CHOP group (2-year EFS, 40% versus 82%; OS, 61% versus 90%, both P<0.001). Multivariate analysis including the five parameters of International Prognostic Index (IPI) and two-categorized IPI revealed that SIL-2R was an independent prognostic factor for EFS and OS in the RCHOP group as well as in the CHOP group. CONCLUSIONS: Our results demonstrate that SIL-2R retains its prognostic value in the rituximab era. The prognostic value of SIL-2R in DLBCL patients receiving rituximab-combined chemotherapy should be reassessed on a larger scale and by long-term follow-up.

CD5 expression is potentially predictive of poor outcome among biomarkers in patients with diffuse large B-cell lymphoma receiving rituximab plus CHOP therapy.

BACKGROUND: Several biomarkers indicating poor prognosis have been reassessed in patients receiving rituximab combination chemotherapy for diffuse large B-cell lymphoma (DLBCL). However, few studies have investigated outcome in relation to a combination of these biomarkers. In addition, no large-scale studies have reassessed the outcome of patients with CD5-positive DLBCL treated with rituximab. PATIENTS AND METHODS: We conducted a retrospective study and investigated the predictive value of three biomarkers -- BCL2, germinal center (GC) phenotype and CD5 -- in 121 DLBCL patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone. RESULTS: CD5-positive patients showed significantly poorer event-free survival (EFS) and overall survival (OS) than CD5-negative patients (2-year EFS, 18% versus 73%, P < 0.001; 2-year OS, 45% versus 91%, P = 0.001). However, no significant difference in outcome according to BCL2 or GC phenotype was observed. Multivariate analysis revealed that CD5 expression was a significant prognostic factor for EFS [hazard ratio 14.2, 95% confidence interval (CI) 4.7-43.2] and OS (hazard ratio 20.3, 95% CI 3.6-114.4). CONCLUSIONS: CD5 expression was the only significant prognostic factor among the biomarkers examined in this study. Further studies with larger numbers are warranted to confirm the prognostic significance of CD5 expression for patients with DLBCL receiving rituximab-containing chemotherapy.

Long-term results of nail fusion plasty of the duplicated thumb.

SUMMARY: We report the long-term results of nail fusion plasty in eight duplicated thumbs. These eight cases were hypoplastic, with nails less than 80% the size of that on the normal side. We operated on these duplicated thumbs using a technique that we developed. We evaluated postoperative nail shape in our series using both our and Tada's scoring systems. The average follow-up period was 12 years. Excellent results were obtained in six cases, with natural-looking nails and even curvature. One case showed acceptable results. Only one case had uneven curvature and a gap in the nail. To reconstruct a natural-looking nail, it is important to correctly design and suture together two nails under no tension. To obtain one nail with even curvature, bones are left floating so that the nail can grow with a natural transverse curve without interference. This technique yielded promising results on long-term follow-up.

Lack of Bcl11b tumor suppressor results in vulnerability to DNA replication stress and damages.

Bcl11b/Rit1 is involved in T-cell development and undergoes chromosomal rearrangements in human T-cell leukemias. Thymocytes of Bcl11b(-/-) newborn mice exhibit apoptosis at a certain developmental stage when thymocytes re-enter into the cell-cycle. Here, we show that Bcl11b-knockdown T-cell lines, when exposed to growth stimuli, exhibited apoptosis at the S phase with concomitant decreases in a cell-cycle inhibitor, p27 and an antiapoptotic protein, Bcl-xL, owing to transcriptional repression. This repression was a likely consequence of the impairment of Sirt1, a nicotinamide adenine dinucleotide-dependent deacetylase associating with Bcl11b. Activation of the apoptotic process cleaved the mediator protein, Claspin, and inhibited phosphorylation of cell-cycle checkpoint kinase 1 (Chk1) that plays a central role in sensing and responding to incomplete replication. Bcl11b(-/-) thymocytes also failed to phosphorylate Chk1 when UV irradiated. These results implicate Bcl11b in the remedy for DNA replication stress and maintenance of genomic integrity.

Multi-step lymphomagenesis deduced from DNA changes in thymic lymphomas and atrophic thymuses at various times after gamma-irradiation.

Whole-body gamma-irradiation to mice causes thymic atrophy where a population of precancerous cells with mutation can be found. Thus, clonal growth and DNA changes at Bcl11b, Ikaros, Pten, Notch1 and Myc were examined in not only thymic lymphomas but also in atrophic thymuses at various times after irradiation. Clonal expansion was detected from the distinct patterns of rearrangements at the TCRbeta receptor locus in a fraction of atrophic thymuses at as early as 30 days after irradiation. This expansion may be in part owing to the rearranged TCRbeta signaling because the transfer of bone marrow cells with the rearrangement and the wild-type locus into severe-combined immunodeficiency mice showed preferential growth of the rearranged thymocytes in atrophic thymus. Loss of heterozygosity (LOH) at Bcl11b and trisomy of Myc were found at high frequencies in both lymphomas and atrophic thymuses, and in contrast, LOH at Ikaros and Pten were rare in atrophic thymuses but prevalent in lymphomas. Notch1 activation was detected in lymphomas and in atrophic thymuses only at a late stage. Similar patterns of DNA changes were found in atrophic thymuses induced in Bcl11b(+/-) mice. These results suggest the order of genetic changes during lymphomagenesis, Bcl11b and Myc being at the early stage; whereas Ikaros, Pten and Notch1 at the late stage.

p53 prevents maturation of T cell development to the immature CD4-CD8+ stage in Bcl11b-/- mice.

Signaling pathways such as the pre-TCR and Wnt pathways regulate alpha/beta T cell differentiation in thymus. Mice lacking an essential component of the pre-TCR exhibit arrest at the (CD4(-)CD8(-)) (CD44(-)CD25(+)) stage (DN3) of thymocyte development, and introduction of p53 deficiency into those mice abrogates this arrest, resulting in transition to the (CD4(+)CD8(+)) double-positive (DP) stage. This paper examines the effect of inactivation of p53 on thymocyte development in Bcl11b(-/-) mice that exhibit arrest at the DN3 or (CD4(-)CD8(+)) immature single-positive (ISP) stage. No DP thymocytes were detected in thymocytes of adoptive transfer experiments in scid mice that were derived from p53(-/-)Bcl11b(-/-) precursors but ISP thymocytes increased in the proportion and in the cell number approximately three times higher than those from Bcl11b(-/-) precursors. Consistently, the level of apoptosis decreased to the level of wild-type precursors. These results suggest that inactivation of p53 is sufficient for DN3 thymocytes to differentiate into the ISP, but not to DP, stage of thymocyte development in Bcl11b(-/-) mice. This provides evidence for a novel p53-mediated checkpoint that regulates the transition from the DN3 to ISP stage of thymocyte development.

Boron neutron capture therapy (BNCT) for malignant melanoma with special reference to absorbed doses to the normal skin and tumor.

Twenty-two patients with malignant melanoma were treated with boron neutron capture therapy (BNCT) using 10B-p-boronophenylalanine (BPA). The estimation of absorbed dose and optimization of treatment dose based on the pharmacokinetics of BPA in melanoma patients is described. The doses of gamma-rays were measured using small TLDs of Mg2SiO4 (Tb) and thermal neutron fluence was measured using gold foil and wire. The total absorbed dose to the tissue from BNCT was obtained by summing the primary and capture gamma-ray doses and the high LET radiation doses from 10B(n, alpha)7Li and 14N(n,p)14C reactions. The key point of the dose optimization is that the skin surrounding the tumour is always irradiated to 18 Gy-Eq, which is the maximum tolerable dose to the skin, regardless of the 10B-concentration in the tumor. The neutron fluence was optimized as follows. (1) The 10B concentration in the blood was measured 15-40 min after the start of neutron irradiation. (2) The 10B-concentration in the skin was estimated by multiplying the blood 10B value by a factor of 1.3. (3) The neutron fluence was calculated. Absorbed doses to the skin ranged from 15.7 to 37.1 Gy-Eq. Among the patients, 16 out of 22 patients exhibited tolerable skin damage. Although six patients showed skin damage that exceeded the tolerance level, three of them could be cured within a few months after BNCT and the remaining three developed severe skin damage requiring skin grafts. The absorbed doses to the tumor ranged from 15.7 to 68.5 Gy-Eq and the percentage of complete response was 73% (16/22). When BNCT is used in the treatment of malignant melanoma, based on the pharmacokinetics of BPA and radiobiological considerations, promising clinical results have been obtained, although many problems and issues remain to be solved.