Non‐invasive estimation of 10B‐4‐borono‐L‐phenylalanine‐derived boron concentration in tumors by PET using 4‐borono‐2‐18F‐fluoro‐phenylalanine

In boron neutron capture therapy (BNCT), ¹⁰B‐4‐borono‐L‐phenylalanine (BPA) is commonly used as a ¹⁰B carrier. PET using 4‐borono‐2‐¹⁸F‐fluoro‐phenylalanine (¹⁸F‐FBPA PET) has been performed to estimate boron concentration and predict the therapeutic effects of BNCT; however, the association between tumor uptake of ¹⁸F‐FBPA and boron concentration in tumors remains unclear. The present study investigated the transport mechanism of ¹⁸F‐FBPA and BPA, and evaluated the utility of ¹⁸F‐FBPA PET in predicting boron concentration in tumors. The transporter assay revealed that 2‐aminobicyclo‐(2.2.1)‐heptane‐2‐carboxylic acid, an inhibitor of the L‐type amino acid transporter, significantly inhibited ¹⁸F‐FBPA and ¹⁴C‐4‐borono‐L‐phenylalanine (¹⁴C‐BPA) uptake in FaDu and LN‐229 human cancer cells. ¹⁸F‐FBPA uptake strongly correlated with ¹⁴C‐BPA uptake in 7 human tumor cell lines (r = .93; P < .01). PET experiments demonstrated that tumor uptake of ¹⁸F‐FBPA was independent of the administration method, and uptake of ¹⁸F‐FBPA by bolus injection correlated well with BPA uptake by continuous intravenous infusion. The results of this study revealed that evaluating tumor uptake of ¹⁸F‐FBPA by PET was useful for estimating ¹⁰B concentration in tumors.     

Health‐related quality‐of‐life in patients with head‐and‐neck cancer in Sri Lanka: psychometric properties of the ‘Sinhala’ version of the EORTC QLQ‐H&N35

Objective: To translate and validate the ‘Sinhala’ language version of the European Organization for Research and Treatment of Cancer head‐and‐neck cancer‐specific health‐related quality‐of‐life questionnaire module, the QLQ‐H&N35, for use in Sri Lanka. Methods: Psychometric testing assessed the hypothesized scale structure, scale reliability, construct validity and acceptability of the translated version of the QLQ‐H&N35 in a consecutive series of 196 newly diagnosed head‐and‐neck cancer patients, recruited from tertiary‐care oncology treatment centres in Sri Lanka. Results: Compliance was high (97.5%), although nearly 40% of patients required assistance with completion of the questionnaire. Twenty‐four sexually inactive patients declined to answer one or both items of the sexuality scale. Multi‐trait scaling confirmed the overall scale structure, with good item‐convergent (100%) and ‐discriminant (93.8%) validity, and scaling success (86.8%) rates. Cronbach's alpha coefficients exceeded 0.70 for all scales, except problems with sexuality (0.60) and problems with senses (0.61), which also evidenced a lower scaling success rate (50%). Confirmation of construct validity included satisfactory results for inter‐scale correlations and known‐groups comparisons for most scales; most correlations were statistically significant (p<0.01), with conceptually related scales showing relatively higher correlation. Most scale scores were able to discriminate clearly between pre‐ and current treatment patients. Conclusions: Results of the study provide strong support for the psychometric robustness of the ‘Sinhala’ version of the QLQ‐H&N35. It may be advisable to interpret the two items assessing sensory problems separately, and to elicit information on sexuality from only those who are sexually active. Copyright © 2009 John Wiley & Sons, Ltd.     

O‐phospho‐L‐tyrosine protects TP53 wild‐type cells against ionizing radiation

O‐phospho‐L‐tyrosine (P‐Tyr) has been reported previously to inhibit growth of several cancer cell lines at mM concentrations. In the present study, we investigated the effect of this compound on tumor cells and normal cells in combination with radiation exposure. It could be demonstrated for the first time that P‐Tyr at μM concentrations protects TP53 wild‐type cells against ionizing radiation (SF4 minus BBI = 0.28, SF4 plus BBI = 0.45). On the contrary, human transformed or tumor cell lines characterized by mutated or functional inactivated TP53 were not altered or increased in their radiation sensitivity (SF4 minus BBI = 0.32, SF4 plus BBI = 0.22). Treatment of wild‐type TP53 cells with P‐Tyr induced stabilization of TP53 within 3 and 16 hours and a subsequent increase in CDKN1A expression after treatment. Consequently, a 16‐hours pretreatment of cells with P‐Tyr led to a significant radioprotective effect. This was not observed in cell lines with mutated TP53, which shows no radioprotection by P‐Tyr. Thus, the present data suggest that P‐Tyr‐mediated radioprotection is dependent on preirradiation stabilization of TP53. The results indicate that P‐Tyr is a radioprotective agent that can potentially be very useful and easy to deliver for radiation protection in general and especially in radiation therapy of TP53‐mutated tumors. © 2002 Wiley‐Liss, Inc.     

miR‐135b‐ and miR‐146b‐dependent silencing of calcium‐sensing receptor expression in colorectal tumors

Studies have shown that the calcium‐sensing receptor (CaSR) mediates the antitumorigenic effects of calcium against colorectal cancer (CRC). Expression of the CaSR in colorectal tumors is often reduced. We have reported previously that silencing of CaSR in CRC is caused in part by methylation of CaSR promoter 2 and loss of histone acetylation. We investigated the impact of aberrant microRNA expression on loss of CaSR expression. A microarray study in two Caco‐2 subclones (Caco2/AQ and Caco2/15) that have similar genetic background, but different CaSR expression levels (Caco2/AQ expressing more CaSR than Caco2/15), identified 22 differentially expressed microRNAs that potentially target the CaSR. We validated these results by performing gain‐ and loss‐of‐function studies with the top candidates: miR‐9, miR‐27a, miR‐135b, and miR‐146b. Modulation of miR‐135b or miR‐146b expression by mimicking or inhibiting their expression regulated CaSR protein levels in two different colon cancer cell lines: Caco2/AQ (moderate endogenous CaSR expression) and HT29 (low endogenous CaSR levels). Inhibition of miR‐135b and miR‐146b expression led to high CaSR levels and significantly reduced proliferation. In samples of colorectal tumors we observed overexpression of miR‐135b and miR‐146b, and this correlated inversely with CaSR expression (miR‐135b: r = ?0.684, p < 0.001 and miR‐146b: r = ?0.448, p < 0.001), supporting our in vitro findings. We demonstrate that miR‐135b and miR‐146b target the CaSR and reduce its expression in colorectal tumors, reducing the antiproliferative and prodifferentiating actions of calcium. This provides a new approach for finding means to prevent CaSR loss, developing better treatment strategies for CRC.     

Early 18F‐2‐fluoro‐2‐deoxy‐d‐glucose positron emission tomography may identify a subset of patients with estrogen receptor‐positive breast cancer who will not respond optimally to preoperative chemotherapy

BACKGROUND:

A pathologic complete response (pCR) and minimal residual disease (pMRD) after preoperative chemotherapy (PCT) for early stage or locally advanced breast cancer (BC) correlates with a good prognosis.

METHODS:

Patients who received from 6 to 8 cycles of PCT for BC were monitored by ¹⁸F‐2‐fluoro‐2‐deoxy‐D‐glucose positron emission tomography (¹⁸F‐FDG‐PET), and the maximal standardized uptake value (SUVmax) was calculated at baseline, after 2 cycles, after 4 cycles, and at the end of PCT. SUVmax percentage changes (Δ‐SUV) were compared with the pathologic response rate. Patients who had a pCR or pMRD in the tumor and an absence of cancer cells in ipsilateral axillary lymph nodes were defined as having obtained an optimal pathologic response (pR), whereas all the other conditions were classified as a pathologic nonresponse (pNR).

RESULTS:

Of 34 patients, 7 (21%) achieved a pR (3 patients had a pCR, and 4 patients had pMRD). After the second cycle, the Δ‐SUV threshold with optimal negative predictive value to predict a pR was 50%. Twenty‐six patients (76%) had a Δ‐SUV >50%, including all 7 patients who had a pR and 19 patients who had a pNR. Conversely, all 8 patients who had a Δ‐SUV ≤50% had a pNR. All 8 of those patients had estrogen recepetor‐positive tumors.

CONCLUSIONS:

Early evaluation of metabolic response by ¹⁸F‐FDG‐PET during PCT was able to identify 30% of patients, all with estrogen receptor‐positive tumors, who would not obtain pR after completion of chemotherapy program. Cancer 2010. © 2010 American Cancer Society.     

MiR‐483‐5p and miR‐139‐5p promote aggressiveness by targeting N‐myc downstream‐regulated gene family members in adrenocortical cancer

Adrenocortical carcinoma (ACC) is a tumor with poor prognosis in which overexpression of a panel of microRNAs has been associated with malignancy but a very limited number of investigations on their role in ACC pathogenesis have been conducted. We examined the involvement of miR‐483‐5p and miR‐139‐5p in adrenocortical cancer aggressiveness. Using bioinformatics predictions and mRNA/miRNA expression profiles, we performed an integrated analysis to identify inversely correlated miRNA–mRNA pairs in ACC. We identified N‐myc downstream‐regulated gene family members 2 and 4 (NDRG2 and NDRG4) as targets of miR‐483‐5p and miR‐139‐5p, respectively. NDRG2 and NDRG4 expressions were inversely correlated respectively with miR‐483‐5p and miR‐139‐5p levels in aggressive ACC samples from two independent cohorts of 20 and 44 ACC. Moreover, upregulation of miR‐139‐5p and downregulation of NDRG4 demonstrated a striking prognostic value. A direct interaction between miR‐483‐5p or miR‐139‐5p and their targets was demonstrated in reporter assays. Downregulation of miR‐483‐5p or miR‐139‐5p in the ACC cell lines NCI‐H295R and SW13 increased NDRG2 or NDRG4 mRNA and protein expression, compromised adrenocortical cancer cell invasiveness and anchorage‐independent growth. MiR‐483‐5p or miR‐139‐5p overexpression and NDRG2 or NDRG4 inhibition produce similar changes, which are rescued by NDRG2 or NDRG4 ectopic expression. We established that key factors mediating epithelial‐to‐mesenchymal transition are downstream effectors of miR‐483‐5p/NDRG2 and miR‐139‐5p/NDRG4 pathways. Collectively, our data show for the first time that miR‐483‐5p/NDRG2 and miR‐139‐5p/NDRG4 axes promote ACC aggressiveness, with potential implications for prognosis and therapeutic interventions in adrenocortical malignancies.     

Classifying B‐cell non‐Hodgkin lymphoma by using MIB‐1 proliferative index in fine‐needle aspirates

BACKGROUND:

MIB‐1 proliferation index (PI) has proven helpful for diagnosis and prognosis in non‐Hodgkin lymphomas (NHLs). However, validated cutoff values for use in fine‐needle aspiration (FNA) samples are not available. We investigated MIB‐1 immunocytochemistry as an ancillary technique for stratifying NHL and attempted to establish PI cutpoints in cytologic samples.

METHODS:

B‐cell NHL FNA cases with available cytospins (CS) MIB‐1 immunocytochemistry results were included. Demographic, molecular, immunophenotyping and MIB‐1 PI data were collected from cytologic reports. Cases were subtyped according to the current World Health Organization classification and separated into indolent, aggressive, and highly aggressive groups. Statistical analysis was performed with pairwise Wilcoxon rank sum test and linear discriminant analysis to suggest appropriate PI cutpoints.

RESULTS:

Ninety‐one NHL cases were subdivided in 56 (61.5%) indolent, 30 (33%) aggressive, and 5 (5.5%) highly aggressive lymphomas. The 3 groups had significantly different MIB‐1 PIs from each other. Cutpoints were established for separating indolent (<38%), aggressive (≥38% to ≤80.1%) and highly aggressive (>80.1%). The groups were adequately predicted in 76 cases (83.5%) using the cutpoints and 15 cases showed discrepant PIs.

CONCLUSIONS:

MIB‐1 immunohistochemistry on CS can help to stratify B‐cell NHL and showed a significant increase in PI with tumor aggressiveness. Six misclassified cases had PIs close to the cutpoints. Discrepant MIB‐1 PIs were related to dilution of positive cells by non‐neoplastic lymphocytes and to the overlapping continuum of features between diffuse large B‐cell lymphoma and Burkitt lymphoma. Validation of our approach in an unrelated, prospective dataset is required. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.     

μ‐Calpain regulates caspase‐dependent and apoptosis inducing factor‐mediated caspase‐independent apoptotic pathways in cisplatin‐induced apoptosis

Cisplatin, an effective anticancer agent, can induce tumor cell apoptosis via caspase‐dependent and‐independent pathways. However, the precise mechanism that regulates the pathways remains unclear. In this study, we showed that μ‐calpain mediated both caspase‐dependent and‐independent pathways during cisplatin‐induced apoptosis in human lung adenocarcinoma cells. After cisplatin treatment, calpain activation, as measured by a fluorescent substrate, was an early event, taking place well before apoptosis inducing factor (AIF) release and caspase‐9/‐3 activation. Confocal imaging of cells transfected with AIF‐GFP demonstrated that AIF release occurred about 9 hr after cisplatin treatment. The increase of μ‐calpain activity proved to be a crucial event in the apoptotic machinery, as demonstrated by the significant protection of cell death in samples suppressed the endogenous μ‐calpain expression level, as well as cotreated with the calpain inhibitors, calpeptin and PD150606. Inhibition of μ‐calpain not only significantly reduced caspase‐9/‐3 activities but also completely blocked AIF redistribution. Our study also showed that endogenous mitochondrial μ‐calpain could directly induce the truncation and release of AIF, while caspases and cathepsins were not necessary for this process. In conclusion, the study demonstrated that activation of μ‐calpain played an essential role in regulating both caspase‐dependent and AIF‐mediated caspase‐independent apoptotic pathways in cisplatin‐induced apoptosis. © 2009 UICC     

The NF‐κB‐modulated miR‐19a‐3p enhances malignancy of human ovarian cancer cells through inhibition of IGFBP‐3 expression

Ovarian cancer is the most lethal gynecologic malignancy due to the lack of symptoms until advanced stages, and new diagnosis and treatment strategy is in urgent need. In this study, we found higher expression of miR‐19a‐3p in ovarian cancer tissues compared with that in the adjacent normal tissues. By chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA) analysis, we showed that nuclear factor‐kappaB (NF‐κB) binds to the promoter of miR‐19a‐3p, leading to reduced expression in ovarian cancer cells. Further study indicated that miR‐19a‐3p inhibits the expression of insulin‐like growth factor binding protein‐3 (IGFBP‐3), resulting in enhanced growth and migration of ovarian cancer cells in vitro and tumor growth in vivo. These results showed that miR‐19a‐3p enhances the oncogenesis of ovarian cancer through inhibition of IGFBP‐3 expression, and which can be inhibited by NF‐κB, suggesting an NF‐κB/miR‐19a‐3p/IGFBP‐3 pathway in the oncogenesis of ovarian cancer, which expands our understanding of ovarian cancer and they may contribute to the development of new diagnosis and treatment of ovarian cancer.     

Ikaros is a critical target during simultaneous exposure to X‐rays and N‐ethyl‐N‐nitrosourea in mouse T‐cell lymphomagenesis

Cancer risk associated with radiation exposure is considered the result of concurrent exposure to other natural and manmade carcinogens. Available data on the molecular characteristics of cancer after simultaneous exposure to radiation and chemicals are insufficient. In our study, we used a mouse thymic lymphoma (TL) model that was synergistically induced by simultaneous exposure to X‐rays and N‐ethyl‐N‐nitrosourea (ENU) at subcarcinogenic doses and analyzed the mutation frequency and spectrum of the TL‐associated genes Ikaros, Notch1, p53 and Kras. We found that the point mutation frequency in Ikaros was significantly increased to 47% for simultaneous exposure compared to 13 and 0% for X‐ray and ENU exposure alone, respectively. These mutations were mostly G:C > A:T at non‐CpG sites and T:A > C:G, both of which are characteristic of ENU mutagenesis. About half of the point mutations were accompanied by loss of heterozygosity (LOH), typical of X‐irradiation. The remaining half did not include LOH, which suggests that they were dominant‐negative mutations. In Notch1, the frequency of abnormalities was high (>58%) regardless of the treatment, suggesting that Notch1 aberration may be important for T‐cell lymphomagenesis. The p53 and Kras mutation frequencies were low for all treatments (<23%). Importantly, the frequency of TLs containing mutations in multiple genes, especially both Ikaros and Notch1, increased after simultaneous exposure. Thus, after simultaneous exposure, Ikaros is a critical target and is inactivated by ENU‐induced point mutations and/or X‐ray‐induced LOH in T‐cell lymphomagenesis. Furthermore, concomitant alterations of multiple tumor‐associated genes may contribute to enhanced lymphomagenesis after simultaneous exposure.     

Improved survival of chimeric antigen receptor‐engineered T (CAR‐T) and tumor‐specific T cells caused by anti‐programmed cell death protein 1 single‐chain variable fragment‐producing CAR‐T cells

Chimeric antigen receptor‐engineered T (CAR‐T)‐cell therapy holds significant promise for the treatment of hematological malignancies, especially for B‐cell leukemia and lymphoma. However, its efficacy against non‐hematological malignancies has been limited as a result of several biological problems characteristic of the tumor microenvironment of solid tumors. One of the main hurdles is the heterogeneous nature of tumor‐associated antigens (TAA) expressed in solid tumors. Another hurdle is the inefficient activation and limited persistence of CAR‐T cells, mainly as a result of T‐cell exhaustion caused by immunosuppressive factors in the tumor microenvironment. In the present study, to address these problems, we engineered CAR‐T cells to produce antagonistic anti‐programmed cell death protein 1 (PD‐1) single‐chain variable fragment (scFv), by which PD‐1‐dependent inhibitory signals in CAR‐T cells and adjacent tumor‐specific non‐CAR‐T cells are attenuated. In mouse solid tumor models, PD‐1 scFv‐producing CAR‐T cells induced potent therapeutic effects superior to those of conventional CAR‐T cells, along with a significant reduction of apoptotic cell death not only in CAR‐T cells themselves but also in TAA‐specific T cells in the tumor tissue. In addition, the treatment with anti‐PD‐1 scFv‐producing CAR‐T cells resulted in an increased concentration of PD‐1 scFv in tumor tissue but not in sera, suggesting an induction of less severe systemic immune‐related adverse events. Hence, the present study developed anti‐PD‐1 scFv‐producing CAR‐T cell technology and explored its cellular mechanisms underlying potent antitumor efficacy.     

Oncogenic microRNA‐27a is a target for anticancer agent methyl 2‐cyano‐3,11‐dioxo‐18β‐olean‐1,12‐dien‐30‐oate in colon cancer cells

Methyl 2‐cyano‐3,11‐dioxo‐18β‐olean‐1,12‐dien‐30‐oate (CDODA‐Me) is a synthetic derivative of glycyrrhetinic acid, a triterpenoid phytochemical found in licorice extracts. CDODA‐Me inhibited growth of RKO and SW480 colon cancer cells and this was accompanied by decreased expression of Sp1, Sp3 and Sp4 protein and mRNA and several Sp‐dependent genes including survivin, vascular endothelial growth factor (VEGF), and VEGF receptor 1 (VEGFR1 or Flt‐1). CDODA‐Me also induced apoptosis, arrested RKO and SW480 cells at G₂/M, and inhibited tumor growth in athymic nude mice bearing RKO cells as xenografts. CDODA‐Me decreased expression of microRNA‐27a (miR‐27a), and this was accompanied by increased expression of 2 miR‐27a‐regulated mRNAs, namely ZBTB10 (an Sp repressor) and Myt‐1 which catalyzes phosphorylation of cdc2 to inhibit progression of cells through G₂/M. Both CDODA‐Me and antisense miR‐27a induced comparable responses in RKO and SW480 cells, suggesting that the potent anticarcinogenic activity of CDODA‐Me is due to repression of oncogenic miR‐27a. © 2009 UICC     

Use of non‐steroidal anti‐inflammatory drugs and risk of non‐Hodgkin lymphoma: a systematic review and meta‐analysis

Epidemiological study findings regarding the association between use of non‐steroidal anti‐inflammatory drugs (NSAIDs) and risk of non‐Hodgkin lymphoma (NHL) have been inconsistent. We aimed to systematically review epidemiological studies of the association and calculate pooled relative risks using meta‐analytic methods. We searched eight electronic literature databases and three clinical trial registers to identify all studies (including observational studies and randomized clinical trials) of the association published prior to October 2013. Identified studies were independently reviewed by two researchers. We used a random effects model to calculate pooled odds ratio (PORs). Heterogeneity amongst studies was examined using Cochran's Q and I‐squared (I²) tests; and sources of heterogeneity were explored using subgroup and meta‐regression analyses. A total of 17 studies (12 case‐control studies and five cohort studies), all adult studies, were included. Use of NSAIDs was not associated with overall risk of NHL [POR = 1.05, and 95% confidence interval (95% CI) 0.90–1.22] or NHL subtypes including B‐cell lymphoma, T‐cell lymphoma, follicular lymphoma, diffuse large B‐cell lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Aspirin use was associated with reduced risk of CLL/SLL (POR = 0.70, 95% CI 0.54–0.91) but not with the risk of all NHLs (POR = 1.02, 95% CI 0.89–1.17). Use of non‐aspirin NSAIDs was associated with increased risk of NHL (POR = 1.41, 95% CI 1.01–1.97) amongst females only. The epidemiologic evidence remains inconclusive. Effects of NSAIDs may differ by drug type, NHL subtype, and sex and more studies taking into consideration these differences are needed. Copyright © 2014 John Wiley & Sons, Ltd.