Search

Cure for multiple myeloma is rare; the success of treatment is measured by response, and length of remissions and survival. Initial treatment for patients young and fit enough is high-dose chemotherapy with autologous stem cell transplantation. Various chemotherapy regimens are employed as initial therapy in patients who cannot withstand the autologous stem cell transplantation regimen, and for treatment of refractory or relapsed disease. Commonly used agents either alone or in combination have included dexamethasone, vincristine, doxorubicin, melphalan, cyclophosphamide, etoposide, cisplatin and, more recently, thalidomide. Within the past few years, the first-in-class proteasome inhibitor bortezomib has been introduced for the treatment of relapsed multiple myeloma with data demonstrating efficacy and safety. Throughout Europe, a faculty of experts conducted a series of debates with over 450 clinicians to discuss the efficacy of bortezomib vis-à-vis other available therapies. Of primary concern was the place of bortezomib in maximizing efficacy throughout the course of the disease and treatment by increasing response rates and improving duration of response, while maintaining an acceptable level of toxicity. The experts concluded that bortezomib, with its unique mechanism of action and demonstrated clinical efficacy and safety, should be considered as standard, early treatment in patients with relapsed multiple myeloma, especially after first relapse.

Cardiac glycosides (CGs), prescribed to treat cardiovascular alterations, display potent anti-cancer activities. Despite their well-established target, the sodium/potassium (Na+/K+)-ATPase, downstream mechanisms remain poorly elucidated. UNBS1450 is a hemi-synthetic cardenolide derived from 2″-oxovorusharin extracted from the plant Calotropis procera, which is effective against various cancer cell types with an excellent differential toxicity. By comparing adherent and non-adherent cancer cell types, we validated Mcl-1 as a general and early target of UNBS1450. A panel of CGs including cardenolides ouabain, digitoxin and digoxin as well as bufadienolides cinobufagin and proscillaridin A allowed us to generalize our findings. Our results show that Mcl-1, but not Bcl-xL nor Bcl-2, is rapidly downregulated prior to induction of apoptosis. From a mechanistic point of view, we exclude an effect on transcription and demonstrate involvement of a pathway affecting protein stability and requiring the proteasome in the early CG-induced Mcl-1 downregulation, without the involvement of caspases or the BH3-only protein NOXA. Strategies aiming at preventing UNBS1450-induced Mcl-1 downregulation by overexpression of a mutated, non-ubiquitinable form of the protein or the use of the proteasome inhibitor MG132 inhibited the compound’s ability to induce apoptosis. Altogether our results point at Mcl-1 as a ubiquitous factor, downregulated by CGs, whose modulation is essential to achieve cell death.

This article has been retracted consistent with Elsevier Policy on Article Withdrawal. Please see . The Publisher apologises for any inconvenience this may cause.

This article has been retracted consistent with Elsevier Policy on Article Withdrawal. Please see . The Publisher apologises for any inconvenience this may cause.

The neo-adjuvant, surgical and adjuvant treatment of gastric adenocarcinoma. Current expert opinion derived from the Seventh World Congress on Gastrointestinal Cancer, Barcelona, 2005.

The inducible transcription factor nuclear factor kappaB (NF-kappaB) plays a central role in the regulation of immune, inflammatory and carcinogenic responses. While normal activation of NF-kappaB is required for cell survival and immunity, its deregulated expression is a characteristic of inflammatory and infectious diseases. In this study, we investigated the molecular mechanisms induced by lactones and chalcones isolated from Fijian kava (Piper methysticum) used in traditional medicine against urinary tract infections and asthma. In order to understand underlying regulatory mechanisms, inhibition of both NF-kappaB-driven reporter gene expression and TNFalpha-induced binding of NF-kappaB to a consensus response element was achieved at concentrations of 320 microM (flavokavain A), 175 microM (flavokavain B) and 870 microM (kavain and dihydrokavain). Moreover, kavain and flavokavains A and B treatment led to inhibition of both inhibitor of kappaB (IkappaB) degradation and subsequent translocation of p50 and p65 NF-kappaB subunits from the cytoplasm to the nucleus as shown by Western blot analysis. Additionally, kinase selectivity screening demonstrates that flavokavain A, but not kavain, nor flavokavain B, inhibits the IkappaB kinase (IKK) as well as PRAK (p38-regulated/activated kinase), MAPKAP-K3 (MAPK-activated protein kinase 3), DYRK1A (dual-specificity tyrosine-phosporylated and regulated kinase 1A) and Aurora B. Altogether, these results give a first insight into anti-inflammatory mechanisms triggered by traditionally used chemopreventive kava compounds.

Cancer-related anemia is a cytokine-mediated disorder resulting from complex interactions between tumor cells and the immune system. Overexpression of certain inflammatory cytokines results in shortened survival of red blood cells, suppression of erythroid progenitor cells, impaired iron utilization, and inadequate erythropoietin production. Numerous other factors may also contribute to the development of anemia in cancer patients. The European Cancer Anaemia Survey (ECAS) has provided the most current, comprehensive, prospectively collected data on the incidence and prevalence of anemia among cancer patients, as well as important perspectives on anemia treatment and relationship of hemoglobin and performance status. ECAS enrolled over 15,000 treated and untreated patients with various malignancies from cancer centers in 24 European countries and followed them for up to 6 months. The initial analysis of the ECAS data revealed that 39% of the total cancer patient population was anemic (hemoglobin

GATA-1 is the founding member of the GATA family of transcription factors. GATA-1 and GATA family member GATA-2 are expressed in erythroid and megakaryocytic lineages, in which they play a crucial role in cell maturation and differentiation. GATA-1 regulates the transcription of many specific and nonspecific erythroid genes by binding to DNA at the consensus sequence WGATAR, which is recognized by all of the GATA family of transcription factors. However, it was identified in eosinophilic cells and also in Sertoli cells in testis. Its activity depends on close cooperation with a functional network of cofactors, among them Friend of GATA, PU.1, and CBP/p300. The GATA-1 protein structure has been well described and includes two zinc fingers that are directly involved in the interaction with DNA and other proteins in vivo. GATA-1 mutations in the zinc fingers can cause deregulation of required interactions and lead to severe dysfunction in the hematopoietic system.

Over-expression of glutathione S-transferase P1 is related to chemotherapeutic drug resistance as well as to differentiation of human erythroleukemia cells. In opposition to previously described differentiating inducers which enhance the GST-resistance phenotype, time- and concentration-dependent activation of both erythroid and megakaryocytic differentiation pathways by butyric acid progressively diminished GSTP1 mRNA expression. GSTP1 mRNA expression decreased by 25% (p0.01) and 64% (p0.01) in 1mM and 2mM butyric acid-differentiated K562 cells, respectively. These results were associated to both a reduction of GATA-1 binding activity to the GSTP1 promoter and to a posttranscriptional destabilization of GSTP1 mRNA in a concentration dependent manner. Indeed, GSTP1 mRNA half-life decreased from 43.8 to 36.2 h and 12.6 h in 1mM- and 2mM-treated cells, respectively.

This paper is a review of the recommendations for the prophylaxis of acute emesis induced by moderately emetogenic chemotherapy as concluded at the third Perugia Consensus Conference, which took place in June 2009. The review will focus on new studies appearing since the Second consensus conference in April 2004. The following issues will be addressed: dose and schedule of antiemetics, different groups of antiemetics such as corticosteroids, serotonin(3) receptor antagonists, dopamine(2) receptor antagonists, and neurokinin(1) receptor antagonists. Furthermore, antiemetic prophylaxis in patients receiving multiple cycles of moderately emetogenic chemotherapy will be reviewed. Consensus statements are given, including optimal dose and schedule of serotonin(3) receptor antagonists, dexamethasone, and neurokinin(1) receptor antagonists. The most significant recommendations (and changes since the 2004 version of the guidelines) are as follows: the best prophylaxis in patients receiving moderately emetogenic chemotherapy (not including a combination of an anthracycline plus cyclophosphamide) is the combination of palonosetron and dexamethasone on the day of chemotherapy, followed by dexamethasone on days 2-3. In patients receiving a combination of an anthracycline plus cyclophosphamide, a combination of a serotonin(3) receptor antagonist plus dexamethasone, plus the neurokinin(1) receptor antagonist aprepitant on the day of chemotherapy, followed by aprepitant days 2-3, is recommended.

Glutathione S-transferase P1-1 (GSTP1-1) is a phase II drug metabolism enzyme implicated in carcinogenesis and development of resistance to anti-cancer drugs. It was previously shown that both activating protein 1 (AP-1) and nuclear factor kappaB (NF-kappaB) are involved in its regulation. In the present study we examined the inhibitory effect of several chemopreventive agents on the tumor necrosis factor (TNF) alpha- or 12-O-tetradecanoylphorbol 13 acetate (TPA)-induced promoter activity of GSTP1-1, as demonstrated by transient transfection experiments in K562 and U937 leukemia cells. Our results provide evidence for a differential effect of chemopreventive agents such as beta-lapachone, emodin, sanguinarine and capsaicin, which significantly inhibit reporter gene expression as well as TNFalpha- and TPA-induced binding of AP-1 and NF-kappaB, whereas trans-anethole and silymarin do not produce any inhibitory effect. Our results demonstrate the ability of selected chemopreventive agents to decrease GSTP1-1 gene expression mechanisms and could thus contribute to reduce the incidence of glutathione related drug resistance in human leukemia.

GSTP1-1 gene expression mechanisms were investigated in hemin-induced erythroid differentiation of K562 cells. Hemoglobin production during differentiation was followed by a significant increase in GSTP1-1 mRNA (1.7-fold, P < 0.01) and protein (1.2-fold, P < 0.01) after 4 days of induction. This increase in mRNA production was not due to transcriptional up-regulation by GATA-1 previously shown to regulate GSTP1-1 during erythroid and megakaryocytic differentiation. Moreover, a drastic decrease in differentiation-specific GATA-1 mRNA expression was correlated to a reduction in GATA-1 promoter binding activity. Neither AP-1 nor NF-κB transcription factor binding activities could provide an explanation to the GSTP1-1 mRNA overexpression in hemin-treated cells. GSTP1-1 mRNA stability analysis using actinomycin D as an inhibitor of mRNA neosynthesis showed that mRNA half-life was doubled in hemin-induced erythroid differentiation of K562 cells. These results allow us to add stabilization of GSTP1-1 mRNA as a novel regulatory mechanism during hemin-mediated differentiation of K562 cells.

Glutathione S-transferases (GST) are involved in cellular protection against xenobiotics, oxidative stress as well as in resistance against chemotherapeutic compounds such as doxorubicin. Levels of human placental type GSTP1-1 are known to be increased in many tumors and hematopoietic diseases. In this work, we compare transcriptional mechanisms in cells that express or not GSTP1-1. Transient transfection assays are used to show that different GST-promoter reporter constructs generate cell-type specific levels of luciferase activity. In expressing cells, transcriptional activity is strongly dependent on AP-1 binding elements within the -65 to -75 bp region of the GSTP1 gene as shown by site-directed mutagenesis. Electrophoretic mobility shift assays show that DNA binding activity is exclusively observed in GSTP1-1-expressing cells and is increased after stimulation with hydrogen peroxide, TPA, tert-butylhydroquinone and doxorubicin. Non-expressing cells present neither constitutive nor inducible AP-1 binding. Taken together, our results provide evidence for the induction of the GSTP1 gene via AP-1 binding activity in leukemia cells and contribute to a better understanding of the molecular events regulating genes involved in drug resistance mechanisms.

Expression of glutathione S-transferase P1-1 (GSTP1-1) is correlated to carcinogenesis and resistance of cancer cells against chemotherapeutic agents. Curcumin, a natural compound extracted from Curcuma longa, has shown strong antioxidant and anticancer properties and also the ability to regulate a wide variety of genes that require activating protein 1 and nuclear factor kappaB (NF-kappaB) activation. In the present study, we examined the inhibitory effect of curcumin on the expression of GSTP1-1 mRNA as well as protein, and we correlated this inhibition with the apoptotic effect of curcumin on K562 leukemia cells. Curcumin efficiently inhibited the tumour necrosis factor alpha- and phorbol ester-induced binding of AP-1 and NF-kappaB transcription factors to sites located on the GSTP1-1 gene promoter. TNFalpha-induced GSTP1-1 promoter activity was also inhibited by curcumin as shown by reporter gene assay. In parallel, curcumin induced pro-caspases 8 and 9 as well as poly ADP ribose polymerase cleavage and thus leading to apoptosis in K562 cells. Our results overall add a novel role for curcumin as this chemoprotective compound could contribute to induce apoptosis by its ability to inhibit the GSTP1-1 expression at the level of transcription.

For several years it has been possible to routinely detect numerous mutations in the human genome by different methods. The most common technique is a standard PCR, but real time fluorescence PCR is increasingly being used. The purpose of this paper is to compare these two different techniques from the point of view of reliability, time consumption, and cost. More than 600 DNA samples of prevalence studies and from cancer patients were used to determine mutations in the genes of coagulation factor V Leiden, prothrombin, and methylenetetrahydrofolate reductase using standard PCR. A subset of 132 samples from the same pool was also tested by LightCycler PCR for the same coagulation gene mutations. Originally LightCycler techniques were applied for quantitative PCR by real time fluorescence measuring. Adding a melting curve analysis allows mutation detection. The results were perfectly concordant. The cost for the reagents is nearly the same for both methods but the time consumption for standard PCR is much higher than for the LightCycler method, resulting in higher laboratory personnel costs.

Under visible irradiation, [Ru(TAP)2(phen)]2+(Cl-)2, [Ru(TAP)2(POQ-Nmet)]2+(Cl-)2 and [Ru(bpy)2(phen)]2+(Cl-)2 were able to dramatically reduce the in vitro transcription of a plasmid DNA template by a bacteriophage RNA polymerase. This photoactivity is related to two different mechanisms of reactivity towards DNA exhibited by these complexes under illumination.

High-dose chemotherapy (HDCT) with peripheral blood stem cell support is often used in high-risk patients with breast cancer. Most investigators performing these procedures provide anecdotal experience that complete remissions occur more commonly with HDCT than standard therapy. However, prospective studies have not convincingly demonstrated an advantage of HDCT in either the adjuvant or metastatic disease setting. The emergence of newer agents, such as the taxanes and trastuzumab, and their incorporation into treatment regimens may create a new standard against which HDCT must be evaluated. In addition, the heterogeneity of breast cancer patients represents an important barrier that must be addressed in future evaluations of HDCT. New prospective, randomized, clinical trials of HDCT are needed, which will incorporate the newer anticancer agents in standard therapy and enroll patients according to multiple well-defined risk factors. Until these studies are conducted, many questions will remain unanswered concerning the role of HDCT in breast cancer. Given its encouraging results in other malignancies, there is ample evidence to continue evaluating HDCT in controlled clinical trials. Semin Oncol 29 (suppl 8):16-20. Copyright 2002, Elsevier Science (USA). All rights reserved.

Biosimilars have been available for a short period of time in hematology-oncology, and prescribing physicians have been wondering about their similarity in terms of safety and efficacy compared with standard comparator. In general, the market penetration in various countries is very similar to that of generic drugs, following prescription habits of the medical profession, variously dependent on the financial and administrative pressures of the country’s environment. A major difference compared to generics is that for biosimilars, before marketing, the European Medicines Agency (EMEA) and the US Food and Drug Administration (FDA) require producers to carry out additional clinical trials for efficacy and safety, as well as formal postmarketing surveillance. These requirements are therefore fulfilled at the time of marketing, at least in those countries dependent on these regulatory authorities. The European Union (EU) has developed a legal basis for biosimilars. EMA regulations require that the reference product be authorized in the EU. If this is also the case for other non-EU countries, it could require duplication of studies for each region. International guidelines can facilitate bringing to market and approvals. The World Health Organisation (WHO) has and is developing EU-similar procedures, as are many countries. It is interesting that Australia more or less adopted EMA regulations for biosimilars in 2008. With regards to the original natural human product, standard drugs produced by genetic engineering are already biosimilars. Over time, due to technical changes in cell cultures and other changes, these have also changed and are not necessarily identical to the initially marketed product (various insulins, erythropoietin [EPO], granulocytopoietins, thrombopoietins, etc.). Standard generic drugs were accepted a few years ago, albeit with some difficulties, and the discussion of biosimilars is a different one. In this issue of “Targeted Oncology”, a panel of international authors explores various regulatory, clinical and economic aspects. The topics are of direct interest to hematologists and oncologists. The area of biosimilars started in other medical areas with insulin, human growth hormone, etc., and will develop more in hematology and oncology in the near future with monoclonal antibodies and others. For presently available biosimilars, a measurable endpoint is, for the most part, proof of efficacy. For instance, for EPO, the standard parameter of response is the hemoglobin level, and the other aspects of this cytokine’s effects on angiogenesis, apoptosis, cellular differentiation, etc., are clinically less marked. Nevertheless, lately the association with thromboembolic disorders, possibly secondary to the effect on vascular endothelium has been widely discussed. The same applies to an effect on tumor progression that is still not fully settled. Long-term follow-up is necessary, due to the fact that, as seen in the present example, years after usage an unexpected adverse effect in relation to a production change, such as antibody-mediated pure red blood cell aplasia, has been noted. The example of low molecular weight heparins (LMWH) demonstrates other practical and conceptual difficulties. Heparins have a pleotrophic effect. Measuring the effect of LMWH is not limited to pharmacokinetics or pharmacodynamics laboratory parameters. It is not enough to determine This article is a modified reprint of Dicato M (2011) Biosimilars: Is absence of proof of difference, proof of absence of difference? Oncologie 13:181–182

To study the relationship between methylation and the transcriptional activity of the minimal promoter of the glutathione S-transferase GSTP1 gene encoding glutathione S-transferase P1-1, GSTP1 mRNA levels as well as basal promoter activity were compared in human leukemia cell lines. The K562 erythroleukemia cell line presented a strong GSTP1 promoter activity, as measured in transient transfection assays using a luciferase reporter plasmid, and correlated with a high mRNA whereas in Raji cells no mRNA was expressed. In order to establish a relationship between the expression and the methylation status, we used in vitro bisulfite sequencing which indicated that both methylated and unmethylated GSTP1 promoter alleles coexisted in K562 cells, whereas Raji lymphoma cells showed a nearly uniform hypermethylation of the promoter region. To determine the impact of methylation, we used in vitro SssI methylation of the minimal GSTP1 promoter, which led to the silencing of the promoter activity in transient transfection assays in expressing K562 as well as in non-expressing Raji cells. These data are in good agreement with previously obtained results and indicate that methylation of CpG sites of the basal promoter is an essential mechanism in the control of GSTP1 gene expression in human leukemia.

Overexpression of the glutathione S-transferase P1 (GSTP1) gene is related to drug resistance in human cancer cells. However, the mechanisms of the transcriptional activation of this gene remain unclear. In this study, we examined the molecular mechanisms underlying phorbol ester mediated gene regulation using human K562 leukemia cells as a model. Promoter deletion analyses revealed that the activator protein-1 (AP-1) transcription factor site was crucial for 12-O-tetradecanoyl phorbol 13-acetate (TPA)-mediated GSTP1 gene transcription. Electrophoretic mobility shift assays and transient transfection analysis demonstrated that both DNA binding and transactivation activities of AP-1 were induced by TPA. By supershift analysis, we identified transcription factors c-jun and fra-1 as well as NF-E2p45 as components of the induced binding complex. These results show for the first time that the phorbol ester TPA is involved in the molecular mechanism(s) mediating the activation of the GSTP1 promoter in a human leukemia model.

Mutations in the p53 tumor suppressor gene are usually associated with an advanced development of colorectal cancer characterized by the transition from the adenoma to the carcinoma stage. We used the polymerase chain reaction (PCR) followed by single-strand conformation polymorphism (SSCP) analysis to screen for the presence of mutations in the p53 gene of patients from Luxembourg and the German Saar region with colorectal cancers at various developmental stages. While we detected no mutations in 16 colic polypi at an early to intermediate stage (adenoma), we revealed seven (13.7C%c) non-silent point mutations (transitions) in exons 5 to 9 of the p53 gene in 51 colorectal tumors at a late stage (carcinoma). In addition to confirming previous observations, these results show that PCR-SSCP analysis can provide both a sensitive and rapid method for the genetic determination of the histopathological stage of colorectal samples. (Resume d'auteur)

The treatment of nausea and vomiting in patients receiving high doses of irradiation and/or chemotherapeutic agents as preparation for hematopoietic stem cell transplantation is discussed. Such patients have very high rates of both early and delayed emesis. Based on the available evidence it is recommended that 5-HT3 receptor antagonists be used to combat emesis in this setting. Continued research is also required to define the optimal antiemetic strategy for these patients.

Recent investigations of colorectal cancer (CRC) have suggested that the accumulation of specific alterations in cell-growth regulating genes trigger the stage-wise progression to malignancy and that at least some of them could be useful for prognosis. In this study, the frequency, location and type of mutations of the Ki-ras proto-oncogene exons 1-2 and p53 tumour-suppressor gene exons 5-9 were analysed in colorectal carcinomas of 72 patients from the European Saar-Luxembourg region using PCR-SSCP screening and direct sequencing. The incidences of Ki-ras activating and p53 inactivating point mutations in these European samples were much lower (Ki-ras: 5 (6.9%) and p53: 13 (18.1%)) than reported for both genes in American studies (40-50% at least) (P < 1 x 10(-3)). These results suggest that other genetic mechanisms than those proposed for the classic adenoma-carcinoma sequence model can frequently underlie CRC development and that Ki-ras and p53 mutations should not be considered as universal markers for CRC.

The mdr1 gene, first member of the human multidrug-resistance gene family, is a major gene involved in cellular resistance to several drugs used in anticancer chemotherapy. Its product, the drug-excreting P-glycoprotein, shows a bipartite structure formed by two similar adjacent halves. According to one hypothesis, the fusion of two related ancestral genes during evolution could have resulted in this structure. The DNA sequence analysis of the introns located in the region connecting the two halves of the human mdr1 gene revealed a highly conserved poly(CA) · poly (TG) sequence in intron 15 and repeated sequences of the Alu family in introns 14 and 17. These repeated sequences most likely represent “molecular fossils” of ancient DNA elements which were involved in such a recombination event.

Arterial thrombosis is not a specific cancer related disorder except in some patients on some antiangiogenic drugs, but remains an infrequent event compared to venous thromboembolism (VTE). VTE is the second most frequent cause of death in cancer patients and is a predictor of mortality in hospitalized cancer patients. The death rate is about 30% in cancer patients when VTE occurs within 3 months of diagnosis. About 15% of patients suffering from cancer will have a VTE during the course of their disease and about 10% of patients with an idiopathic (?) VTE develop a cancer in the following two years. Risk factors for VTE in oncology are patient dependent, treatment dependent, type of cancer and stage dependent, The pathophysiology of VTE is complex. In addition to the standard causes, biomarkers and a clinical risk assessment score can be useful in deciding on time and duration of VTE prophylaxis and treatment. Prophylactic treatment in the ambulatory cancer patient needs to be discussed as newer anticoagulants like ultra low molecular weight heparin have been used recently in clinical trials and other novel agents (dabigatran, rivaroxaban and apixaban) marketed for orthopedic surgery and atrial fibrillation have become routine. The latter drugs are given orally, have negligeable interference with other medications or with foodstuffs and do not need laboratory surveillance. Approval for market release in VTE therapy in the general medical situation is pending and will certainly be used in the oncological setting if cost compatible. Various guidelines (ESMO, ASCO, NCCN …) are concurrent in their recommendations depending on disease activity, anti-cancer treatments (surgery, chemotherapy …) and the patient's clinical situation. These will be discussed in regards to the ambulatory and hospitalized patient, for first episode and for recurrent VTE. Some data are available though not presently recommended, for anticoagulant therapy in oncology for improving survival. Disclosure The author has declared no conflicts of interest.

Introduction In order to evaluate various SNP's in different genes and chromosomal locations in Caucasian patients as markers of the predisposition to the colorectal cancer (CRC) disease, we analyzed the frequency of different tumour-associated single-nucleotide polymorphisms in several genes including p53 and SMAD7 of Caucasian CRC patients as compared to a healthy Caucasian control population. Methods Tumour samples were obtained from 188 CRC patients at the adenocarcinoma stage and from 98 healthy control individuals. After gDNA extraction, selected amplicons were amplified by PCR, followed by melting curve analysis. The statistical evaluation of the difference in genotype frequency at the different SNPs comparing CRC patients with healthy controls was carried out using the Chi-squared test. Results When analyzing 188 tumour samples and comparing with 98 healthy controls, a significant difference in the genotype distribution of the G429C SNP in the p53 gene was observed (P = 0.046). Similarly, a significant difference was found for rs4939827 C > T in the SMAD7 gene (P = 0.037), although no significant differences were found for rs4464148 T > C (P = 0.585) or rs12953717 C > T (P = 0.197) also in SMAD7. Differences in genotype distribution for CHR9 C > A rs719725 and CHR8 G > A rs7014346 were almost significant (P = 0.050 and P = 0.054 respectively). Significant results previously reported for two other genes were confirmed:- PAI, 5G vs. 4G, rs1799899 (P = 0.047) and TGFBR1 A > G rs334348, G > A rs334349 and A > C rs1591 (P Conclusion The results for p53, SMAD7, PAI, CHR8 and CHR9 are suggestive rather than conclusive and invite confirmation through further study. Concerning the association between the TGFBR1 SNP's and colorectal cancer, on the other hand, the results are already clear. For example, with the TGFBR1 SNP rs334348, the frequency of the GG genotype was as much as 43% for the CRC patients but 11% for the controls, while the frequency of the AA genotype was only 18% for the patients and 43% for the controls. Adding further markers like SNPs for SMAD7, PAI, CHR8 and CHR9 is not significant, p53 though statistically borderline (P = 0.046) does not add clinical relevance.

Gene amplification is responsible both for dihydrofolate reductase induced methotrexate resistance, and for the P-glycoprotein encoding multigene family induced multidrug resistance. The 6 pairs of hydrophobic regions of the P-glycoprotein fold up in a snake-like structure through the lipidic layers of the cell membrane. Other detoxification mechanisms include the glutathione S-transferase 'pi', but without gene amplification.

In a retrospective analysis of the literature, Hryniuk et al suggested a significant relationship between dose intensities of combination chemotherapies and tumor response rate in advanced breast carcinoma (BC) [1].

Multiple myeloma is, despite the emergence of new treatment strategies in recent years, still a lethal disease in 2005. Over the last several years, significant insights into the dysregulation of various signal transduction pathways of MM have emerged and have evolved the development of new agents. Histone deacetylase inhibitors as valproic acid are compounds that inhibit HDACs enzymes that, in conjunction with histone acetylases, regulate the acetylation state of histones and, by extension, the conformational status of chromatin. VPA is clinically known to be used in treatment of different types of epileptic disease. Effects and signal transduction pathways of cell death have been studied in cells harvested and purified from routine bone marrow aspirates of several patients with multiple myeloma, as well as on myeloma cell lines (OPM2, U266) treated with a physiologic dose range of valproic acid (1–4 mM). We observe significant in vitro toxicity starting at doses of 1 mM for 24h in cell lines as well as in patient cells using an XTT based cytotoxicity assay. The question we adressed was the mechanisms by which the MM died. Flow cytometric analysis with PI / Annexin V staining does not show apoptosis features, nor do TUNEL staining or DNA fragmentation assays, suggesting non activation of the intrinsic apoptosis pathway. In contrast, cell morphology of treated cells stained with May-Gruenwald-Giemsa staining show increase in multinucleated giant cells. Multinucleation has often been described in cells which die through mitotic catastrophe. Further experiments exploring this hypothesis will be conducted. Effect of 48h valproic ac on myeloma cell lines Effect of 48h valproic ac on myeloma cell lines Effect of 48h valproic ac on CD138 cells from myeloma patients Effect of 48h valproic ac on CD138 cells from myeloma patients

In order to identify specific DNA sequences useful as ‘genetic landmarks’ in the construction of a complete map of the human mdr1 (multidrug-resistance) gene, we investigated the introns in the central region. In intron 14, we identified a long stretch of a homopyrimidine·homopurine sequence most probably adopting an unconventional DNA conformation, followed by a cluster of three Alu repeated sequences in an inverted orientation. Here, we describe the structure, formation and nucleotide sequence of these DNA elements.