Uncovering the clinical impact of kallikrein-related peptidase 5 (KLK5) mRNA expression in the colorectal adenoma-carcinoma sequence.

Background Kallikrein-related peptidases (KLKs) are a subgroup of serine proteases located on chromosome 19q13.3. Most KLKs have been extensively studied as potential biomarkers for several carcinomas and other diseases. KLK5 was originally identified from a keratinocyte library, and its enzyme was purified from the stratum corneum of human skin. KLK5 was shown to be differentially expressed in a variety of endocrine tumors, although it is not as yet examined widely in colorectal cancer (CRC). Methods In this study, we quantitatively assessed the mRNA expression status of KLK5 in 197 colorectal tissues from 133 patients (70 cancerous and their paired normal colonic mucosa for 64 of them, as well as 63 colorectal adenomas) by quantitative real-time PCR (qPCR) using TaqMan probes. Statistical analysis evaluated the results. Results It was shown that KLK5 expression is reduced following the histologically non-cancerous-adenoma sequence (p<0.001), whereas it is increased during the sequence adenoma-carcinoma (p<0.001). Furthermore, KLK5 positive expression is associated with positive nodal status (p=0.022), advanced tumor stage (p=0.038) and high histological grade (p=0.033). Cox univariate analysis revealed that KLK5 positive expression is associated with disease-free survival (DFS) (p=0.028) and overall survival (OS) of patients (p=0.048). Kaplan-Meyer survival models showed that patients with positive KLK5 expression have lower DFS (p=0.009) and OS (p=0.019). Receiver operating characteristic (ROC) analysis demonstrated for first time that KLK5 expression had significant discriminatory values between cancer and adenoma tissues (area under the curve [AUC] 0.77; 95% confidence interval [CI]=0.69-0.85, p=0.03). Conclusions KLK5 mRNA expression may be useful for the differentiation of CRC from colorectal adenoma and represents a potential unfavorable prognostic biomarker for CRC.

Human kallikrein-related peptidase 12 (KLK12) splice variants discriminate benign from cancerous breast tumors.

OBJECTIVES: As kallikrein-related peptidase 12 (KLK12) has been implicated in the cancer progression and alternative splicing plays significant role in this disease, the aim of this study was to examine the expression profile and the clinical impact of the KLK12 splice variants in breast cancer. DESIGN AND METHODS: Total RNA was isolated and reverse transcripted from 141 tissues. Afterwards, quantitative real-time PCR were conducted, followed by the performance of the comparative CT (2-ΔΔCT) method for relative quantification, whilst their correlation with the clinicopathological features of breast malignancies were assessed by statistical analysis. RESULTS: Both KLK12sv1/2 and KLK12sv3 showed higher expression in non-cancerous than in cancerous samples. KLKsv1/2 (P = 0.001) upregulated and KLK12sv3 (P < 0.001) downregulated in the malignant compared to the benign tumors and their discriminative ability was verified by ROC curve analysis. Moreover, KLK12sv3 was associated with grade (P = 0.012) and hormonal receptor status (P = 0.001). Furthermore, Kaplan-Meier and Cox regression analyses showed that patients with positive KLK12sv1/2 and KLK12sv3 levels presented a significantly longer disease-free survival (P = 0.014 and P = 0.013, respectively) and overall survival (P = 0.062 and P = 0.004, respectively). CONCLUSIONS: Our results demonstrate the discriminative value of KLK12sv1/2 and KLK12sv3 between benign and malignant breast tumors as well as their potential favorable prognostic significance in breast adenocarcinoma.

Kallikrein-related peptidase 6 (KLK6) expression in the progression of colon adenoma to carcinoma.

KLK6 is a secreted trypsin-like serine protease. KLK6 mRNA expression and its association with colon cancer (CC) progression was studied using quantitative real-time PCR. We examined the expression of KLK6 in 232 colon tissues (cancerous, non-cancerous, and adenomatous). We proved that KLK6 expression in CC behaves as a continuous variable, as its expression correlates significantly with increasing tumor stage (p=0.004) and histological grade (p=0.007). Interestingly, the expression of KLK6 in adenomas was significantly higher than that in the cancerous or non-cancerous tissues examined (p<0.001). Cox proportional hazard regression model using univariate analysis revealed that positive KLK6 expression is a significant factor for disease-free survival (DFS) (p=0.017) and overall survival (OS) (p=0.002) of patients. Kaplan-Meier survival curves demonstrated that KLK6-negative expression is significantly associated with longer DFS (p=0.009) and OS (p=0.001). ROC analysis showed that KLK6 expression has significant discriminatory power in distinguishing cancerous from non-cancerous colon tissues (p<0.001), or cancerous from adenoma tissues (p=0.001), or adenoma from non-cancerous colon tissues (p<0.001). Additionally, strong KLK6 immunostaining was seen in the cancer cells of selected CC sections, as well as in glandular cells and inflammatory cells of adenomas. In conclusion, KLK6 may represent a potential unfavorable prognostic biomarker for CC.

Parallel overexpression and clinical significance of kallikrein-related peptidases 7 and 14 (KLK7KLK14) in colon cancer.

Currently available colon cancer (CC) markers lack sensitivity and specificity. Kallikrein-related peptidases (KLKs) present a new class of biomarkers under investigation for diverse diseases, including cancer. KLKs are co-expressed in various tissues participating in proteolytic cascades. KLK7 in human tumours facilitates metastasis by degrading components of the extracellular matrix. KLK14 promotes tumourigenesis by activating proteinase-activated receptors. In the present study we examined the concomitant expression of KLK7 and KLK14 in245 colonic tissue specimens from 175 patients; 70 were pairs of cancerous-normal tissues, 31 were cancerous tissues and 74 were colonic adenomas. We used quantitative real-time PCR and proved that both genes are up-regulated in CC at the mRNA level. Receiver-operating characteristic (ROC) analysis of our results showed that both genes have discriminatory value between CC and adenoma tissues, with KLK14 obtaining greater distinguishing power (area under the curve [AUC]=0.708 for KLK14; AUC=0.669 for KLK7). Current work showed that the two genes are fairly co-expressed in all three types of colon tissues examined (normal rs=0.667, p<0.001, adenomas rs=0.373, p=0.001, carcinomas rs=0.478, p<0.001). KLK14 is associated with shorter disease-free survival (DFS) and overall survival (OS) of patients (p=0.003, p=0.016 respectively), whereas KLK7only with shorter DFS (p=0.004). KLK7 and KLK14 gene expression can be regarded as markers of poor prognosis for CC patients with discriminating power between CC and adenoma patients.

Significant alterations in the expression pattern of kallikrein-related peptidase genes KLK4, KLK5 and KLK14 after treatment of breast cancer cells with the chemotherapeutic agents epirubicin, docetaxel and methotrexate.

Given that 1.3 million new cases of breast cancer are universally registered among women and approximately 36 % of the patients die annually, the revelation of new predictive markers for treatment efficiency is of vital importance. Recently, our group has depicted that KLK4, KLK5, and KLK14 are differentially expressed in breast carcinoma. The objective of this study was to determine and investigate the expression pattern of the KLK4, KLK5, and KLK14 genes in breast cancer cells after treatment with established chemotherapeutic agents. We evaluated these genes' expression after treatment of the BT-20 cells with epirubicin, docetaxel and methotrexate, determining their cytotoxic effect by MTT and trypan blue assays. The relative quantification of genes' mRNA levels was performed by using the SYBR Green® chemistry, and the HPRT1 served as an endogenous control gene. The drugs triggered apoptosis in treated cells and induced deregulations in the expression of the above KLKs. The most significant alterations were a 12-fold and tenfold increase of KLK5 in docetaxel and methotrexate-treated cells, respectively, while the KLK4 levels decreased by ten-fold in epirubicin, five-fold in docetaxel and twenty-fold in methotrexate treated-cells, compared to the untreated ones. In the case of KLK14 levels, a twofold increase in epirubicin and threefold decrease in methotrexate-treated cells were observed. Present significant alterations in the expression pattern of KLK4, KLK5, and KLK14 could comprise an initial stage for predicting chemotherapy response in breast cancer and should be further investigated as predictive markers in the future.

Kallikrein-related peptidase 6 (KLK6)gene expression in intracranial tumors.

Kallikrein-related peptidases (KLKs) are emerging novel new biomarkers for prognosis, diagnosis and therapeutic intervention of cancer. Kallikrein-related peptidase 6 (KLK6) has the highest expression in normal brain among other tissues. Although its expression has been extensively studied in many types of cancer and in neurodegenerative diseases, very little is known for its expression in intracranial tumors. In the present study, 73 intracranial tumor samples were examined for KLK6 messenger ribunucleic acid (mRNA) gene expression using quantitative real-time polymerase chain reaction. Statistical analysis revealed the significant association of KLK6 expression with clinical and pathological parameters. Follow-up information was available for a median time of 20 months (range 1-59 months). KLK6 is expressed more frequently in tumors of high malignancy like the glioblastomas (70.6 %) and less in tumors of low malignancy like the meningiomas (12.5 %). KLK6 positive expression is associated with tumor grade (p < 0.001), malignancy status (p < 0.001), and tumor histologic type (p = 0.001). Cox proportional hazard regression model using univariate analysis revealed for the first time that positive KLK6 expression is a significant factor for disease-free survival (DFS; p = 0.041) of patients suffering from intracranial tumors. Kaplan-Meier survival curves demonstrated that negative KLK6 expression is significantly associated with longer DFS (p = 0.032). KLK6 gene expression may have clinical utility as a marker of unfavorable prognosis for intracranial tumors, and consequently, it could be used as target for therapeutic intervention.

Human kallikrein-related peptidase 12 (KLK12) splice variants expression in breast cancer and their clinical impact.

Kallikrein-related peptidases (KLKs) are a group of 15 serine proteases, hormonally regulated, and localized on chromosome 19q13.4. Alternative splicing is a process that plays significant role in the development, physiology, and different diseases, like cancer. Kallikrein family numbers more than 82 alternative transcripts. Understanding the role that those gene transcripts play in various cancer types, could lead to the discovery of diagnostic markers or drug targets. The present study was designed to analyze the expression profile of the splice variants of kallikrein-related peptidase 12 (KLK12) in breast cancer patients and to evaluate their clinical significance. KLK12 splice variants (KLK12sv3 and KLK12sv1/KLK12sv2) were examined in 69 tissue samples of breast cancer using quantitative real-time PCR as well as semi-quantitative PCR. Relative quantitative expression of KLK12 was statistically associated to clinicopathological parameters. From the splice variants examined, statistical associations with clinicopathological parameters were obtained only from KLK12sv3 variant. KLK12sv3 is more frequently expressed in tumors of lower grade (p = 0.040), early patient TNM stage (p = 0.024), and smaller tumor size (p = 0.023). Positive KLK12sv3 expression is associated with longer patient disease-free survival (DFS) (p = 0.042) and higher progesterone receptor concentration (p = 0.008). KLK12sv1/KLK12sv2 expression is statistically associated with KLK12sv3 expression (p = 0.001). KLK12sv3 can be regarded as a marker of good prognosis in breast cancer.

Evaluation of kallikrein-related peptidase 5 expression and its significance for breast cancer patients: association with kallikrein-related peptidase 7 expression.

BACKGROUND: Kallikrein-related peptidases (KLKs) have been proposed as potential cancer biomarkers. Contradictions in literature led us to clarify the role of KLK5 as a breast cancer predictor, as well as its association with KLK7 expression. PATIENTS AND METHODS: Semi-quantitative RT-PCR detected KLKs 5 and 7 in 80 breast tissues, 74 neoplastic and 6 normal. Steroid hormone receptors were quantified in all samples. Associations between KLK5 status and clinicopathological variables, as well as disease-free survival (DFS) and overall survival (OS) of patients were analyzed. RESULTS: Forty tumor tissues showed high KLK5 expression, which was significantly associated with estrogen receptor status. Significant co-expression of KLKs 5 and 7 was observed in the same cancer samples (p=0.02). Increased KLK5 expression was a statistically significant independent prognostic factor for DFS (p=0.009 univariate analysis and p=0.028 multivariate analysis) and OS of patients (p=0.014, univariate analysis). CONCLUSION: Increased KLK5 expression can contribute to the prognosis of DFS and OS of breast cancer patients. KLKs 5 and 7 are co-expressed in breast cancer.

Expression analysis and clinical evaluation of kallikrein-related peptidase 10 (KLK10) in colorectal cancer.

Kallikrein-related peptidases (KLKs) represent a serine protease family having 15 members. KLK10 is a secreted protease with a trypsin-like activity. The function of KLK10 is poorly understood, although it has been suggested that KLK10 may function as a tumor suppressor gene. In human cancer, KLK10 gene shows organ-specific up- or down-regulation. Since KLKs are promising tumor biomarkers, the examination of KLK10 mRNA expression and its association with colorectal cancer (CRC) progression was studied using semi-quantitative PCR. One hundred and nineteen primary CRC specimens were examined for which follow-up information was available for a median period of 29 months (range, 1-104 months). KLK10 expression was found to be significantly associated with TNM stage (p=0.028). Cox proportional hazard regression model using univariate analysis revealed for the first time that high status KLK10 expression is a significant factor for disease-free survival (DFS; p=0.002) and overall survival (OS; p=0.026) of patients. Kaplan-Meier survival curves demonstrated that KLK10 expression of low status is significantly associated with longer DFS (p=0.001) as well as OS (p=0.021), suggesting that KLK10 gene expression may be used as a marker of unfavorable prognosis for CRC. As the epigenetics of cancer are unraveled, KLK10 may represent not only a novel biomarker, but also a promising future therapeutic target for the disease.

Clinical evaluation of PRMT1 gene expression in breast cancer.

Methylation of arginine residues has been implicated in many cellular activities like mRNA splicing, transcription regulation, signal transduction and protein-protein interactions. Protein arginine methyltransferases are the enzymes responsible for this modification in living cells. The most commonly used methyltransferase in man is protein arginine methyltransferase 1 (PRMT1). Since methylation processes appear to interfere in the emergence of several diseases, including cancer, we investigated the localisation of the protein in cancer tissue and, for the first time, the relation that possibly exists between the expression of PRMT1 gene and breast cancer progression. We used tumour specimens from 62 breast cancer patients and semi-quantitative RT-PCR to determine the expression of PRMT1 gene and was found to be associated with patient's age (p = 0.002), menopausal status (p = 0.006), tumour grade (p = 0.03), and progesterone receptor status (p = 0.001). Survival curves revealed that PRMT1-v1 status-low expression relates to longer disease-free survival (DFS; p = 0.036). To the contrary, PRMT1-v2 status is not associated neither with the clinical or pathological parameters nor with DFS (p = 0.31). PRMT1-v3 was not statistically significantly expressed in breast cancer tissue. Selected cancer and normal breast samples were stained for PRMT1. In both normal and cancerous breast tissues, staining was in the cytoplasm and only in rare cases the cell nucleus appeared stained. Present results show a potential use for this gene as a marker of unfavourable prognosis for breast cancer patients.

KLK5 gene expression is severely upregulated in androgen-independent prostate cancer cells after treatment with the chemotherapeutic agents docetaxel and mitoxantrone.

Kallikrein-related peptidases (KLKs), including KLK5, have been proposed as promising biomarkers for prostate cancer diagnosis and prognosis. In the present study, we report that distinct augmentations (up to 6.4-fold) of KLK5 mRNA expressional levels, calculated via quantitative real-time PCR, occur after treatment of DU145 cells with appropriate concentrations, determined by the MTT method, of docetaxel and mitoxantrone. Our data reveal the endogenous need of prostate cancer cells for modified KLK5 expression to cope with the administration of chemotherapeutic drugs. Furthermore, it is proposed that the expression profile of KLK5 could serve as a putative biomarker for monitoring the treatment response in hormone refractory prostate cancer patients.

Colon cancer and protein arginine methyltransferase 1 gene expression.

BACKGROUND: In this study, the possible relation of the expression pattern of arginine methyltransferase 1 and colon cancer progression is investigated. MATERIALS AND METHODS: Colon cancer samples as well as normal colon samples were used to define the arginine methyltransferase 1 expression by RT-PCR. The results were associated with clinical and histological parameters of the tissues. RESULTS: In colon cancer tissue, only PRMT1 variants v1 and v2 were often expressed. Statistical significance for the clinicopathological parameters examined was found only for PRMT1 variant v2. PRMT1 v2 expression was associated with nodal status and tumour grade. PRMT1 v2 expression analysis in 25 pairs of cancerous/non-cancerous colon tissue showed higher or equal expression in cancer versus normal tissue. In 18 inflamed colon tissues examined for PRMT1 expression and compared with the expression of 90 colon cancer tissue samples, statistical significance was found only for variants v1 and v2. A higher percentage of PRMT1 v2 expression was observed in older patients. CONCLUSION: From the present preliminary results, it can be said that PRMT1 variant v2 can probably be regarded as a marker of unfavourable prognosis in colon cancer patients.

Clinical significance of kallikrein-related peptidase 7 (KLK7) in colorectal cancer.

Human tissue kallikrein-related peptidases are a family of 15 secreted serine proteases, located at chromosome 19q13.4. Most of them have been reported to be potential biomarkers for several carcinomas and other diseases. Human tissue kallikrein-related peptidase 7 (KLK7) has been purified from human stratum corneum and resembles a chymotryptic endopeptidase originally called stratum corneum chymotryptic enzyme (SCCE). In this study, we examined for the first time, the prognostic value of KLK7 mRNA expression, using a semi-quantitative RT-PCR method, in 105 colorectal cancer tissues for 54 of which, paired normal colonic mucosa were available. Furthermore, we analysed the expression of KLK7 in 10 adenomas, in 18 biopsies of inflamed colon mucosa, as well as in 22 human cancer cell lines of various origin, four of them being of colon. A defined number of colon cancer samples were also examined by immunohistochemistry. KLK7 expression was higher in cancerous than in normal tissues. Less differentiated tumors of more advanced stage showed higher KLK7 expression. Follow-up analysis revealed that KLK7 was significantly associated with shorter overall survival (OS) and disease-free survival (DFS). In addition, selected colon cancer samples highly expressing KLK7 gene, showed intense immunohistochemical staining for KLK7, enhancing RT-PCR results. Present data suggest that KLK7 gene is up-regulated in colon cancer and its expression predicts poor prognosis for colon cancer patients.

Treatment of PC3 prostate cancer cells with mitoxantrone, etoposide, doxorubicin and carboplatin induces distinct alterations in the expression of kallikreins 5 and 11.

Several of the novel kallikrein-related peptidases (tissue kallikreins; KLKs) are emerging new serum and/or tissue biomarkers for prostate cancer (CaP) diagnosis, prognosis and monitoring. In the present research approach, our objective was to investigate the possible alterations in the mRNA expression levels of KLK5 and KLK11 genes in prostate cancer cells PC3 as a response to treatment with mitoxantrone, etoposide, doxorubicin and carboplatin. Viability was assessed with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay after cell treatment with either mitoxantrone (2 microM), etoposide (20 microM), doxorubicin (1 microM), or carboplatin (15 microM), for 24, 48 and 72 hours. Additionally, trypan blue staining revealed that in PC3 cells all drugs displayed almost the same limited necrotic effects which appeared mainly at 72 hours of treatment. PC3 prostate cancer cells showed a concentration- and time-dependent increased cytotoxicity to the drugs under study which was mainly due to reduction of cell proliferation efficiency. Distinct modulations of KLK5 and KLK11 genes, at the mRNA level, were observed, supporting a drug-dependent cell response. Our experimental data demonstrate that the molecular profile mainly of KLK5 gene may serve as a new potential molecular biomarker predicting treatment response in CaP cells.

Cathepsin B protein levels in endometrial cancer: Potential value as a tumour biomarker.

OBJECTIVE: Lysosomal cysteine protease Cathepsin-B has been implicated in the progression of various human tumours. We examined Cathepsin-B protein levels in endometrial carcinoma patients-mainly post-menopausal-and investigated their possible association with clinical and pathological parameters in order to assess Cathepsin-B's significance as a potential tumour biomarker. METHODS: The indirect immunoperoxidase method was used for Cathepsin-B immunohistochemical staining of 64 paraffin-embedded endometrial tumour tissues, having follow-up period of 18-240 months. Steroid hormone receptors were measured as well. Tissue samples were staged following the FIGO criteria. RESULTS: Positive Cathepsin-B immunostaining was observed in 27 patients (42.2%) and was significantly associated with the FIGO stage of the disease (p=0.006), as well as cervical and stromal invasion (p=0.001 and p=0.037, respectively) and progesterone receptor status (p=0.027). Positive Cathepsin-B expression was also inversely related to Disease-free Survival (p=0.034) and Overall Survival (p=0.035) in univariate analysis, as well as in multivariate analysis (p=0.022 and p=0.035, respectively). CONCLUSION: Increased Cathepsin-B expression was found to be predictive of more aggressive tumour behaviour over time and can be regarded as an unfavourable and independent tumour marker for endometrial cancer patients with a long follow-up.

Prognostic value of the apoptosis related genes BCL2 and BCL2L12 in breast cancer.

Many members of BCL2 (Bcl-2) apoptosis-related genes were found to be differentially expressed in various malignancies and were proposed as prognostic cancer biomarkers. Recently, a new member of the BCL2 gene family, BCL2L12, was cloned and was found to be expressed in mammary gland. In the present study, 55 specimens from patients with, histologically confirmed, epithelial breast carcinoma were analyzed for BCL2 and BCL2L12 gene expression by RT-PCR. Increased expression of BCL2 gene was found in patients belonging to the age groups <45 or >55 years, as well as in estrogen receptors (ER)-positive patients and in BCL2L12-positive tumors. In addition, BCL2 or BCL2L12-positive patients were found to be almost four times less likely to relapse or die in comparison to BCL2 or BCL2L12-negative patients, respectively. Multivariate analysis revealed that BCL2 and BCL2L12 might be used as independent prognostic biomarkers in breast cancer.

Prognostic significance of the expression of SR-A1, encoding a novel SR-related CTD-associated factor, in breast cancer.

SR-A1 is a human high-molecular-weight SR-related CTD-associated factor that links the machineries of transcription and mRNA splicing. In this study we examined the prognostic value of SR-A1 gene expression using a semi-quantitative RT-PCR method. High SR-A1 expression was observed in 31/81 (38.3%) breast cancer tissues and was found to be more frequent in patients with tumors of large size (p=0.027), as well as in lymph node-positive patients (p=0.035). Follow-up analysis revealed that low SR-A1 expression increases the probability of both overall and disease-free survival of patients. Our results suggest that SR-A1 may possibly be characterized as a new marker of unfavorable prognosis for breast cancer.

The role of human tissue kallikreins 7 and 8 in intracranial malignancies.

Recent evidence suggests that many tissue kallikreins are implicated in carcinogenesis. Kallikrein 8 (KLK8) plays a role in the physiology of the central nervous system. Kallikrein 7 (KLK7) takes part in skin desquamation. Both show altered expression in ovarian and breast cancer. In this study, we examined the level of mRNA expression of the KLK7 and KLK8 genes in 73 intracranial tumors using qualitative RT-PCR. The results were correlated with clinical and histomorphological variables and patient outcome. The expression of both genes was also examined in the brain cancer cell lines U-251 MG, D54 and SH-SY5Y and the invasive capacity of glioblastoma cells U-251 MG overexpressing hK7 or hK8 was also investigated in an in vitro Matrigel assay. Follow-up analysis revealed that expression of KLK7 mRNA was associated with shorter overall survival (OS) compared to patients with no KLK7 expression, as determined by Cox proportional hazard regression analysis. Overexpression of hK7 protein by cultivated brain tumor cells significantly enhanced the invasive potential in the Matrigel invasion assay, in contrast to cells overexpressing hK8 protein. Our data suggest that hK7 protein overexpression is associated with a more aggressive phenotype in brain cancer cells.

Topotecan and methotrexate alter expression of the apoptosis-related genes BCL2, FAS and BCL2L12 in leukemic HL-60 cells.

The BCL2 family of genes (B-cell CLL/lymphoma 2; Bcl-2) plays a pivotal role in the highly regulated process of apoptosis. We have recently cloned a newly identified member of this family, BCL2L12, which was found to be differentially expressed in many tumors. It is known that topotecan and methotrexate act through induction of apoptosis in cancer cells. In the present study we investigated the expression profile of the novel apoptotic gene BCL2L12 in relation to other apoptotic genes in the human leukemic cell line HL-60, after treatment with topotecan or methotrexate. The kinetics of apoptosis induction and cell toxicity were investigated by DNA laddering and the MTT method, respectively. Gene expression levels were analyzed by RT-PCR using gene-specific primers. Downregulation of BCL2L12, BCL2 and FAS was observed after treatment of HL-60 cells with topotecan, while treatment with methotrexate led to downregulation of BCL2 and FAS, with no change in BCL2L12 expression. Our results support the significance of mRNA modulations in the expression of apoptosis-related genes during treatment of human leukemic cells with anticancer drugs.