DNA-dependent protein kinase is a therapeutic target and an indicator of poor prognosis in B-cell chronic lymphocytic leukemia.

PURPOSE: del(17p), del(11q), and associated p53 dysfunction predict for short survival and chemoresistance in B-cell chronic lymphocytic leukemia (CLL). DNA-dependent protein kinase (DNA-PK) is activated by DNA damage and mediates DNA double-strand break repair. We hypothesized that inhibiting DNA-PK would sensitize CLL cells to drug-induced DNA damage and that this approach could increase the therapeutic index of agents used to treat CLL. EXPERIMENTAL DESIGN: Fifty-four CLL cases were characterized for poor prognosis markers [del(17p), del(11q), CD38, and ZAP-70]. In selected cases, DNA-PK catalytic subunit (DNA-PKcs) expression and activity and p53 function were also measured. Ex vivo viability assays established sensitivity to fludarabine and chlorambucil and also tested the ability of a novel DNA-PK inhibitor (NU7441) to sensitize CLL cells to these drugs. The effects of NU7441 on fludarabine-induced DNA damage repair were also assessed (Comet assays and detection of gammaH2AX). RESULTS: DNA-PKcs levels correlated with DNA-PK activity and varied 50-fold between cases but were consistently higher in del(17p) (P = 0.01) and del(11q) cases. NU7441 sensitized CLL cells to chlorambucil and fludarabine, including cases with del(17p), del(11q), p53 dysfunction, or high levels of DNA-PKcs. NU7441 increased fludarabine-induced double-strand breaks and abrogated drug-induced autophosphorylation of DNA-PKcs at Ser2056. High DNA-PK levels predicted for reduced treatment-free interval. CONCLUSIONS: These data validate the concept of targeting DNA-PKcs in poor risk CLL, and demonstrate a mechanistic rationale for use of a DNA-PK inhibitor. The novel observation that DNA-PKcs is overexpressed in del(17p) and del(11q) cases indicates that DNA-PK may contribute to disease progression in CLL.     

Downregulated Dicer expression predicts poor prognosis in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the western world. Alterations in microRNAs (miRNAs) expression have been proposed to play a role in CLL pathogenesis. Dicer and Drosha are the main regulators of miRNA biogenesis, and deregulation of their expression has been indicated as a possible cause of miRNA alterations observed in various cancers. To investigate the role of Dicer and Drosha in CLL, we assessed the expression of Dicer and Drosha and their correlation with other prognostic factors, including Binet stages, immunoglobulin heavy chain variable gene (IGHV) mutation status, TP53 mutation status, ZAP-70 protein and CD38 expression level in 165 CLL patients by using real-time polymerase chain reaction methods. Patients with unmutated IGHV genes had significantly lower expression of Dicer than patients with IGHV mutations. The lower expression level of Dicer was also significantly associated with higher level of CD38 and ZAP-70, and more aggressive Binet stage. We also analyzed Dicer expression in different cytogenetic subgroups. Lower Dicer level was found in patients with unfavorable cytogenetic aberrations (deletion in 17p13 or 11q22.3) in contrast to higher level in good risk cytogenetics (deletion in 13q14 as the sole abnormality). Furthermore, the lower expression of Dicer in CLL shows a strong association with shorter overall survival (OS) (P = 0.0046) as well as with reduced treatment free survival (TFS) (P = 0.0006). By contrast, no differences in the expression of Drosha among these groups of patients were observed. Our data suggest that Dicer expression may play an important role in the progression and prognosis of CLL.     

NAT10 upregulation indicates a poor prognosis in acute myeloid leukemia

Background: N-acetyltransferase 10 (NAT10) is considered as an oncogene in many tumors. This study investigated the NAT10 expression in Chinese acute myeloid leukemia (AML) patients and evaluated the predictive significance of NAT10 with a single-center retrospective study. Methods: The Oncomine was used to analyze NAT10 expression in AML. We also collected bone marrow samples of 48 newly diagnosed AML patients and 20 benign individuals in our center. NAT10 mRNA expression levels were detected by real-time qPCR. Clinical data was obtained from inpatient medical records. Results: Two microarrays in Oncomine showed that NAT10 was upregulated in AML. Our data revealed that AML patients had higher NAT10 expression levels than the normal controls (P < 0.01). NPM1-mutant patients had higher NAT10 mRNA levels than NPM1-wt patients. NAT10 expression level was higher in nonremission group than in overall remission group (P < 0.05). High NAT10 expression indicated a poor progression-free survival and overall survival. Conclusions: The results support NAT10 as a potential prognostic and therapeutic biomarker for AML.     

Low T3 syndrome as a predictor of poor prognosis in chronic lymphocytic leukemia

Low triiodothyronine (T3) state is associated with poor prognosis in critical acute and prolonged illness. However, the information on thyroid dysfunction and cancer is limited. The aim of our study was to evaluate the prognostic value of low T3 syndrome in chronic lymphocytic leukemia (CLL). Two hundred and fifty‐eight patients with detailed thyroid hormone profile at CLL diagnosis were enrolled. Low T3 syndrome was defined by low free T3 (FT3) level accompanied by normal‐to‐low free tetraiodothyronine (FT4) and thyroid‐stimulating hormone (TSH) levels. A propensity score‐matched method was performed to balance the baseline characteristics. Multivariate Cox regression analyses screened the independent prognostic factors related to time‐to‐first‐treatment (TTFT) and cancer‐specific survival (CSS). Area under the curve (AUC) assessed the predictive accuracy of CLL‐International Prognostic Index (IPI) together with low T3 syndrome. The results showed that 37 (14.34%) patients had low T3 syndrome, which was significantly associated with unfavorable TTFT and CSS in the propensity‐matched cohort, and it was an independent prognostic indicator for both TTFT and CSS. Serum FT3 level was positively related to protein metabolism and anemia, and inversely related to inflammatory state. Patients with only low FT3 demonstrated better survival than those with synchronously low FT3 and FT4, while those with synchronously low FT3, FT4 and TSH had the worst clinical outcome. Low T3 syndrome together with CLL‐IPI had larger AUCs compared with CLL‐IPI alone in TTFT and CSS prediction. In conclusion, low T3 syndrome may be a good candidate for predicting prognosis in future clinical practice of CLL.     

MAGE-D4B is a novel marker of poor prognosis and potential therapeutic target involved in breast cancer tumorigenesis

Melanoma-associated antigen (MAGE) family members are generally described as tumor-specific antigens. An association between MAGE-D4B and breast cancer has yet to be reported and the functional role of the encoded protein has never been established. We performed microarray analysis of 104 invasive breast tumors and matched non-cancerous breast biopsies. qPCR was used for validation in an independent biobank. To investigate the biological relevance of MAGE-D4B in breast tumorigenesis, its phenotypic effects were assessed in vitro. Overall, MAGE-D4B was detected in 43% of tumors while undetected in normal breast tissue. MAGE-D4B was found to correlate with tumor progression and to be an independent prognostic marker for poor outcome in term of relapse-free and overall survival, with potential predictive relevance in relation to response to chemotherapy. RNA interference-mediated knockdown of MAGE-D4B significantly hampered the invasive properties of Hs578T cells by affecting anchorage-independent growth, adhesion, migration and invasion affecting anchorage-independent growth, adhesion, migration and invasion and by modulating expression of invasion-suppressor gene E-cadherin.     

SKP2 overexpression is associated with a poor prognosis of rectal cancer treated with chemoradiotherapy and represents a therapeutic target with high potential

The S-phase kinase-associated protein 2 (SKP2) oncoprotein is an E3 ubiquitin ligase. Overexpression of SKP2 was found in various human cancers, including colorectal cancers, but its potential role as a prognostic marker after neoadjuvant chemoradiotherapy (CRT) and for therapeutic intervention in rectal cancers is unknown. This study examined the correlation of SKP2 expression in the prognosis of rectal cancer patients and the viability of colorectal cancer cells treated with CRT. SKP2 immunoexpression was retrospectively assessed in pretreatment biopsies of 172 rectal cancer patients treated with neoadjuvant CRT followed by surgery. Results were correlated with clinicopathological features, therapeutic responses, and patient survival. Pharmacologic assays were used to evaluate the therapeutic relevance of Bortezomib in two colorectal cancer cell lines (HT-29 and SW480). High expression of SKP2 was correlated with the advanced Post-Tx nodal status (p?=?0.002), Post-Tx International Union for Cancer Control stage (p?=?0.002), and a lower-degree tumor regression grade (p?<?0.001). Moreover, high expression of SKP2 (p?=?0.027, hazard ratio 3.21) was an independent prognostic factor for local recurrence-free survival. In vitro, Bortezomib downregulated SKP2 expression, induced caspase activation, and decreased the viability of colorectal cancer cells with or without a combination with fluorouracil. Bortezomib also promoted caspase activation and gamma-H2AX formation in colorectal cancer cells concurrently treated with CRT. High expression of SKP2 was associated with a poor therapeutic response and adverse outcomes in rectal cancer patients treated with neoadjuvant CRT. In the presence of chemotherapy with or without radiotherapy, the promoted sensitivity of colorectal cancer cells to Bortezomib with an SKP2-repressing effect indicated that it is a potential therapeutic target.     

Somatic MED12 mutations are associated with poor prognosis markers in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. We performed systematic database search and identified highly specific MED12 mutations in CLL patients. To study this further, we collected three independent sample series comprising over 700 CLL samples and screened MED12 exons 1 and 2 by direct sequencing. Mutations were identified at significant frequency in all three series with a combined mutation frequency of 5.2% (37/709). Positive mutation status was found to be associated with unmutated IGHV and ZAP70 expression, which are well-known poor prognosis markers in CLL. Our results recognize CLL as the first extrauterine cancer type where 5′ terminus of MED12 is mutated at significant frequency. Functional analyses have shown that these mutations lead to dissociation of Cyclin C-CDK8/19 from the core Mediator and to the loss of Mediator-associated CDK kinase activity. Additional studies on the role of MED12 mutation status as a putative prognostic factor as well as mutations'' exact tumorigenic mechanism in CLL are warranted.     

Cullin1 is a novel marker of poor prognosis and a potential therapeutic target in human breast cancer

BackgroundTo investigate the role of Cullin1 (Cul1) in the development of breast cancer, we examined the expression of Cul1 in breast cancer tissues and analyzed the correlation between Cul1 expression and clinicopathologic variables and patients survival.Patients and methodsWe evaluated the Cul1 expression by immunohistochemistry using a tissue microarray (TMA) which includes 393 breast cancer tissues. We also studied the role of Cul1 in breast cancer cell proliferation, migration and invasion by carrying out CCK8 cell proliferation assay, cell migration and invasion assay.ResultsThe Cul1 expression was significantly correlated with breast cancer histology grade (P = 0.000), estrogen receptor status (P = 0.001), progesterone receptor status (P = 0.001) and human epidermal growth factor receptor 2 status (P = 0.002). Furthermore, we showed a strong correlation between high Cul1 expression and worse 5-year overall and disease-specific survival rates in breast cancer patients (P = 0.026 and P = 0.015, respectively). Finally, we found that Cul1 knockdown inhibits cell proliferation, migration and invasion abilities.ConclusionsCul1 overexpression is significantly correlated with breast cancer progression and predicts worse survival. Cul1 regulates breast cancer cell proliferation, migration and invasion.     

GOLPH3 is a novel marker of poor prognosis and a potential therapeutic target in human renal cell carcinoma

Background:

Golgi phosphoprotein 3 (GOLPH3) has been reported to be involved in the development of several human cancers. The present study was conducted to investigate the expression of GOLPH3 and its prognostic significance in renal cell carcinoma (RCC). Meanwhile, the function of GOLPH3 in human RCC was further investigated in cell culture models.

Methods:

Expression of GOLPH3 was examined in 43 fresh RCC tissues and paired adjacent normal renal tissues by real-time quantitative PCR and western blotting. Immunohistochemistry for GOLPH3 was performed on additional 218 RCC tissues. The clinical significance of GOLPH3 expression was analysed. Downregulation of GOLPH3 was performed using small-interfering RNA (siRNA) in Caki-1 and 786-O cells with high abundance of GOLPH3, and the effects of GOLPH3 silencing on cell proliferation, migration, invasion in vitro, and tumour growth in vivo were evaluated.

Results:

Expression of GOLPH3 was upregulated in the majority of the RCC clinical tissue specimens at both mRNA and protein levels. Clinicopathological analysis showed that GOLPH3 expression was significantly correlated with T stage (P<0.001), lymph-node status (P=0.003), distant metastasis (P<0.001), tumour-node-metastasis (TNM) stage (P<0.001), and Fuhman grade (P=0.001). Expression of GOLPH3 was inversely correlated with both overall and recurrence-free survival of RCC patients. Multivariate analysis showed that GOLPH3 expression was an independent prognostic indicator for patient''s survival. Knockdown of the GOLPH3 expression reduced cell proliferation, anchorage-independent growth, migration, invasion, and tumour growth in xenograft model mice.

Conclusions:

These results suggest that GOLPH3 expression is likely to have important roles in RCC development and progression, and that GOLPH3 is a prognostic biomarker and a promising therapeutic target for RCC.     

Steroid effects on ZAP-70 and SYK in relation to apoptosis in poor prognosis chronic lymphocytic leukemia

There is resurgent interest in glucocorticoids (GCs) in the treatment of poor prognosis chronic lymphocytic leukemia (CLL). Little is known however on how GCs induce apoptosis in CLL. Methylprednisolone (MP) induces apoptosis in ZAP-70 positive CLL more readily than in ZAP-70 negative CLL, which is in contrast to the effects of radiation and chemotherapy. The increased GC sensitivity of ZAP-70⁺ CLL was studied in relation to the expression status of ZAP-70 and the related signal transducing tyrosine kinase SYK. Both ZAP-70 and SYK were downregulated by GC treatment. Moreover, SYK was dephosphorylated by the phosphatase PTP1B of which the expression and translation levels were induced by GCs. Inhibition of PTP1B successfully restored ZAP-70 expression and SYK phosphorylation but did not interfere with GC-induced apoptosis. Therefore, the downregulation of ZAP-70 and P-SYK per se during treatment with GCs is not sufficient to induce apoptosis, and different mechanisms must therefore be responsible for the increased steroid sensitivity of ZAP-70⁺ CLL.     

Association of interleukin-6 and interleukin-8 with poor prognosis in elderly patients with chronic lymphocytic leukemia

In population studies, the relative survival in chronic lymphocytic leukemia (CLL) decreases with age. In this study, we demonstrated in a cohort of 189 patients from a CLL clinic that overall survival was lower in the sub-cohort of patients aged ≥ 70 years, but causes of death were similar for all age groups, being progressive CLL, secondary malignancies and infections. As normal individuals age, the plasma levels of inflammatory cytokines, such as interleukin-6 (IL-6) and IL-8, can increase. In our patients with CLL, IL-6, IL-8 and tumor necrosis factor-α (TNF-α) levels increased with age to a greater degree than in normal individuals, and the levels correlated closely with plasma β(2)-microglobulin and with one another. In addition, in patients ≥ 70 years, IL-6 was found to be a better prognostic marker than immunoglobulin variable heavy chain gene (IgV(H)) status. In vitro studies demonstrated that IL-6 and IL-8 could enhance the binding of CLL cells to stromal cells, suggesting that their clinical activity may be mediated through their effects on the microenvironment. Thus, plasma IL-6 is an important prognostic marker for the elderly with CLL, and this study highlights that the utility of prognostic markers may depend on patient age.     

Mammalian target of rapamycin (mTOR) inhibition in chronic lymphocytic B-cell leukemia: a new therapeutic option

Chronic lymphocytic B-cell leukemia (B-CLL) is an incurable disease characterized by the accumulation of monoclonal mature B cells, although disease progression relies upon cycling B-CLL cells in proliferation centers in central lymph organs. Rapamycin and its analogs are immunosuppressant drugs that exert their activity by specific inhibition of the mammalian target of rapamycin (mTOR). mTOR inhibition induces cell cycle arrest not only in normal lymphocytes but also in malignant cells. Therefore, rapamycins have recently entered the field of cancer treatment. In the present review we discuss how progression through the cell cycle is regulated in B-CLL cells and how rapamycin and its analogs can be used as target therapies against proliferating B-CLL cells. We also focus on additional effects of rapamycin, such as targeting the interaction between malignant B cells and the microenvironment.     

The apoptotic pathway: a target for therapy in chronic lymphocytic leukemia

Cell division and apoptosis (programmed cell death) are the two major physiological processes which control the size of cell populations. Chronic lymphocytic leukaemia arises as a result of the clonal expansion of, usually B-, lymphocytes in which a dysregulation of apoptosis leads to prolonged cell survival. The same process becomes exaggerated with increasing drug resistance, the usual cause of treatment failure in this condition. The identification of points in the apoptotic pathway at which dysregulation occurs is beginning to open up new therapeutic opportunities where the conventional cytotoxic chemotherapy approach is found to fail. Although these strategies are still in their infancy they may increase understanding of the pathogenesis of the disorder and overcome the problem of drug resistance.     

Overexpression of LARP1 predicts poor prognosis of colorectal cancer and is expected to be a potential therapeutic target

This study investigated the significance of La-related protein 1 (LARP1) in the development and progression of colorectal cancer (CRC). Quantitative real-time polymerase chain reaction and Western blot analyses were carried out to determine the mRNA and protein expression of LARP1 in CRC tumor tissues and paired adjacent normal mucosa. The expression of LARP1 was upregulated in CRC. Immunohistochemical analysis using tissue microarray was performed. A positive correlation between LARP1 and proliferating cell nuclear antigen (PCNA) in the area of proliferation was observed using the Spearman’s correlation coefficient test (r = 0.332, P < 0.01). The elevated expression of LARP1 significantly correlated with T stage (P = 0.02), N stage (P = 0.006), M stage (P < 0.001), American Joint Committee on Cancer (AJCC) stage (P = 0.04), differentiation rank (P < 0.001), and PCNA level (P < 0.001). In addition, the inhibitory effect of LARP1 knockdown on CRC cell proliferation was demonstrated using Cell Counting Kit-8 (CCK8) and colony-forming cell (CFC) assays. Multivariate analysis showed that LARP1 was an independent prognostic factor for overall survival (OS; hazard rate (HR) = 0.244; 95 % confidence interval (CI), 0.078–0.769; P = 0.016) and disease-free survival (DFS; HR = 0.281; 95 % CI, 0.086–0.917; P = 0.035) in CRC patients. LARP1 plays an important role in the proliferation of colorectal cancer and represents a new prognostic indicator.     

CD147 overexpression is a prognostic factor and a potential therapeutic target in bladder cancer

CD147, also named extracellular matrix metalloproteinase inducer (EMMPRIN), has been shown to be involved in the progression of malignancy by regulating expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). The goal of this study was to evaluate the role of CD147 in the biology of bladder cancer and to determine its potential as a therapeutic target. CD147 protein expression was detected by immunohistochemistry in 108 bladder cancers using a tissue microarray annotated with patient follow-up. In immunohistochemistry, CD147 protein expression was associated with poor prognosis (P < 0.001), lymph node status (P < 0.001), tumor stage (P = 0.003), histologic grade (P = 0.011). Multivariate analysis showed that CD147 overexpression was an independent prognostic factor (P = 0.019). Infection of T24 bladder cancer cells with an adenovirus that expressed a small interfering RNA (siRNA) against CD147 efficiently inhibited CD147 protein and mRNA expression. This resulted in decreased proliferation, soft agar colony formation, migration, and invasion of T24 cells in vitro. Moreover, downregulation of CD147 reduced secretion of MMP-2 and MMP-9 and expression of VEGF in these cells. Our findings suggest that CD147 overexpression plays an important role in progression of bladder cancer, and CD147 could be a potential target of bladder cancer therapy.