Selection of clinically relevant drug concentrations for in vitro studies of candidates drugs for cancer repurposing: a proposal

Drug repurposing of widely prescribed patent-off and cheap drugs may provide affordable drugs for cancer treatment. Nevertheless, many preclinical studies of cancer drug repurposing candidates use in vitro drug concentrations too high to have clinical relevance. Hence, preclinical studies must use clinically achievable drug concentrations. In this work, several FDA-approved cancer drugs are analyzed regarding the correlation between the drug inhibitory concentrations 50% (IC50) tested in cancer cell lines and their corresponding peak serum concentration (Cmax) and area under the curve (AUC) reported in clinical studies of these drugs. We found that for most targeted cancer drugs, the AUC and not the Cmax is closest to the IC50; therefore, we suggest that the initial testing of candidate drugs for repurposing could select the AUC pharmacokinetic parameter and not the Cmax as the translated drug concentration for in vitro testing. Nevertheless, this is a suggestion only as experimental evidence does not exist to prove this concept. Studies on this issue are required to advance in cancer drug repurposing.

Combinational therapies for the treatment of advanced cervical cancer

INTRODUCTION

From a therapeutic standpoint, invasive cervical cancer can be designated as early, locally advanced, and advanced stages. Systemic treatment remains the primary therapeutical modality for advanced cervical cancer patients who are not candidates for local curative treatments (surgery and radiation).

AREAS COVERED

In this review, the author discusses recent clinical studies published in PubMed on the treatment of advanced cervical carcinoma. The author also provides his expert perspectives on the current state of play.

EXPERT OPINION

Survival outcomes for advanced cervical cancer patients have been steadily improving since 1981, when single-agent cisplatin was adopted as the standard of care. In 2014, bevacizumab increased median overall survival (MOS) to 17 months when combined with standard chemotherapy (platinum-paclitaxel). In 2021, the checkpoint inhibitor (CPI) pembrolizumab, when used in the first line added to platinum-paclitaxel-bevacizumab, increased mOS to 24 months. Two other CPIs are in phase III trials as first-line treatments. As for second-line therapy, cemiplimab has shown increased survival compared to single-agent chemotherapy, and a phase III trial with tisotumab vedotin is currently ongoing. Nevertheless, there is still an unmet need for new more effective treatments and significant efforts are needed in the discovery of drugs for advanced cervical cancer beyond the current 'me-too' drugs.

The health system and access to treatment in patients with cervical cancer in Mexico

Cervical cancer (CC) is tightly related to a low Human Development Index. Mexico is an upper-middle-income country with 126 million inhabitants, and its public health system aims to provide universal health coverage. Currently, employment-based social insurance covers approximately 60% of the population, and the scope of the remaining 40% is on course via the "IMSS-Bienestar" Institute. However, the annual government spending on health remains at 3% of the Gross Domestic Product, which is well below the 6% recommended by the Organization for Economic Cooperation and Development. CC is the second in incidence and mortality among women. Regarding primary prevention with the Human Papilloma Virus-vaccine, the current coverage for girls aged 9 to 14 years is only around 7%. Among secondary prevention with screening, the program is yet to cover the total number of women at risk; nevertheless, the age-standardized CC mortality rate has decreased from 12 per 100,000 women in 1979 to 5.7 per 100,000 women in 2020 due in part to increased screening coverage. Still, around two-thirds of patients present with locally advanced disease at diagnosis. Data from our country demonstrate that even socially disadvantaged CC patients achieve "standard" survival outcomes if treatment is granted. Nevertheless, there is a shortage in almost every aspect regarding CC treatment, including oncologists, chemotherapy units, medical physicists, radiation technicians, and both teletherapy and brachytherapy facilities. In conclusion, advances in the public health system in Mexico are urgently required to achieve CC control and reduce the mortality from this neoplasia that mainly targets socially disadvantaged women.

Progress in Metabolic Studies of Gastric Cancer and Therapeutic Implications

Background:

Worldwide, gastric cancer is ranked the fifth malignancy in incidence and the third malignancy in mortality. Gastric cancer causes an altered metabolism that can be therapeutically exploited.

Objective:

To provide an overview of the significant metabolic alterations caused by gastric cancer and propose a blockade.

Methods:

A comprehensive and up-to-date review of descriptive and experimental publications on the metabolic alterations caused by gastric cancer and their blockade. This is not a systematic review.

Results:

Gastric cancer causes high rates of glycolysis and glutaminolysis. There are increased rates of de novo fatty acid synthesis and cholesterol synthesis. Moreover, gastric cancer causes high rates of lipid turnover via fatty acid -oxidation. Preclinical data indicate that the individual blockade of these pathways via enzyme targeting leads to antitumor effects in vitro and in vivo. Nevertheless, there is no data on the simultaneous blockade of these five pathways, which is critical, as tumors show metabolic flexibility in response to the availability of nutrients. This means tumors may activate alternate routes when one or more are inhibited. We hypothesize there is a need to simultaneously blockade them to avoid or decrease the metabolic flexibility that may lead to treatment resistance.

Conclusions:

There is a need to explore the preclinical efficacy and feasibility of combined metabolic therapy targeting the pathways of glucose, glutamine, fatty acid synthesis, cholesterol synthesis, and fatty acid oxidation. This may have therapeutical implications because we have clinically available drugs that target these pathways in gastric cancer.

BAPST. A Combo of Common use drugs as metabolic therapy of cancer-a theoretical proposal

Advances in cancer therapy have yet to impact worldwide cancer mortality. Poor cancer drug affordability is one of the factors limiting mortality burden strikes. Up to now, cancer drug repurposing had no meet expectations concerning drug affordability. The three FDA-approved cancer drugs developed under repurposing -all-trans-retinoic acid, arsenic trioxide, and thalidomide- do not differ in price from other drugs developed under the classical model. Though additional factors affect the whole process from inception to commercialization, the repurposing of widely used, commercially available, and cheap drugs may help. This work reviews the concept of the malignant metabolic phenotype and its exploitation by simultaneously blocking key metabolic processes altered in cancer. We elaborate on a combination called BAPST, which stands for the following drugs and pathways they inhibit: Benserazide (glycolysis), Apomorphine (glutaminolysis), Pantoprazole (Fatty-acid synthesis), Simvastatin (mevalonate pathway), and Trimetazidine (Fatty-acid oxidation). Their respective primary indications are: • Parkinson's disease (benserazide and apomorphine). • Peptic ulcer disease (pantoprazole). • Hypercholesterolemia (simvastatin). • Ischemic heart disease (trimetazidine). When used for their primary indication, the literature review on each of these drugs shows they have a good safety profile and lack predicted pharmacokinetic interaction among them. Most importantly, the inhibitory enzymatic concentrations required for inhibiting their cancer targets enzymes are below the plasma concentrations observed when these drugs are used for their primary indication. Based on that, we propose that the regimen BAPTS merits preclinical testing.

Perspectives on Drug Repurposing

Complex common diseases are a significant burden for our societies and demand not only preventive measures but also more effective, safer, and more affordable treatments. The whole process of the current model of drug discovery and development implies a high investment by the pharmaceutical industry, which ultimately impact in high drug prices. In this sense, drug repurposing would help meet the needs of patients to access useful and novel treatments. Unlike the traditional approach, drug repurposing enters both the preclinical evaluation and clinical trials of the compound of interest faster, budgeting research and development costs, and limiting potential biosafety risks. The participation of government, society, and private investors is needed to secure the funds for experimental design and clinical development of repurposing candidates to have affordable, effective, and safe repurposed drugs. Moreover, extensive advertising of repurposing as a concept in the health community, could reduce prescribing bias when enough clinical evidence exists, which will support the employment of cheaper and more accessible repurposed compounds for common conditions.

The combination of orlistat, lonidamine and 6-diazo-5-oxo-L-norleucine induces a quiescent energetic phenotype and limits substrate flexibility in colon cancer cells

Cancer upregulates glycolysis, glutaminolysis and lipogenesis, and induces a catabolic state in patients. The concurrent inhibition of both tumor anabolism and host catabolism, and the energetic consequences of such an approach, have not previously been fully investigated. In the present study, CT26.WT murine colon cancer cells were treated with the combination of anti-anabolic drugs orlistat, lonidamine and 6-diazo-5-oxo-L-norleucine (DON; OLD scheme), which are inhibitors of the de novo synthesis of fatty acids, glycolysis and glutaminolysis, respectively. In addition, the effects of OLD scheme sumplemented with the combination of anti-catabolic compounds, namely growth hormone, insulin and indomethacin (GII scheme), were also evaluated. The effects of the compounds used in combination on CT26.WT cell viability, clonogenicity and energetic metabolism were assessed in vitro. The results demonstrated that the anti-anabolic approach reduced cell viability, clonogenicity and cell cycle progression, and increased apoptosis. These effects were associated with decreased oxidative phosphorylation, glycolysis and fuel flexibility. Furthermore, the anti-catabolic scheme, alone or supplemented with anti-anabolic compounds, did not favor tumor growth. These findings indicated that the simultaneous pharmacological inhibition of tumor anabolism and host catabolism exhibits antitumor effects that should be further evaluated.

Antitumor effects of ivermectin at clinically feasible concentrations support its clinical development as a repositioned cancer drug

PURPOSE

Ivermectin is an antiparasitic drug that exhibits antitumor effects in preclinical studies, and as such is currently being repositioned for cancer treatment. However, divergences exist regarding its employed doses in preclinical works. Therefore, the aim of this study was to determine whether the antitumor effects of ivermectin are observable at clinically feasible drug concentrations.

METHODS

Twenty-eight malignant cell lines were treated with 5 μM ivermectin. Cell viability, clonogenicity, cell cycle, cell death and pharmacological interaction with common cytotoxic drugs were assessed, as well as the consequences of its use on stem cell-enriched populations. The antitumor in vivo effects of ivermectin were also evaluated.

RESULTS

The breast MDA-MB-231, MDA-MB-468, and MCF-7, and the ovarian SKOV-3, were the most sensitive cancer cell lines to ivermectin. Conversely, the prostate cancer cell line DU145 was the most resistant to its use. In the most sensitive cells, ivermectin induced cell cycle arrest at G₀-G₁ phase, with modulation of proteins associated with cell cycle control. Furthermore, ivermectin was synergistic with docetaxel, cyclophosphamide and tamoxifen. Ivermectin reduced both cell viability and colony formation capacity in the stem cell-enriched population as compared with the parental one. Finally, in tumor-bearing mice ivermectin successfully reduced both tumor size and weight.

CONCLUSION

Our results on the antitumor effects of ivermectin support its clinical testing.

Viral inhibitors of NKG2D ligands for tumor surveillance

INTRODUCTION

Natural Killer cells (NK) are key for the innate immune response against tumors and viral infections. Several viral proteins evade host immune response and target the NK cell receptor NKG2D and its ligands. Areas covered: This review aimed to describe the viruses and their proteins that interfere with the NKG2D receptor and their ligands, and how these interactions lead to immune evasion, host protection, and tissue damage from acute and chronic viral infections. Expert opinion: The study of viral proteins has already impacted the field of oncology. A prime example is the HBV vaccine and the development of antiviral drugs for HIV, Hepatitis C, and the family of Herpesviridae viruses. The NKG2D system seems to be a rational therapeutic target. Nevertheless, an effective cytotoxic response by NK cells is mediated by a network of activating and inhibitory receptors, the integration of which determines if the NK cell becomes cytotoxic or permissive. Immunotherapeutic agents that increase the antitumor lytic activity of NK cells through modulating activation and inhibitory signaling of NK cells are being developed. Nevertheless, more research is needed to dissect the integrative mechanism of NK cells function to fully exploit their antitumor and antiviral effector mechanisms.

Developmental DNA methyltransferase inhibitors in the treatment of gynecologic cancers

INTRODUCTION

DNA methylation has become an attractive target for the treatment of cancer. DNA methyltransferase inhibitors have proven useful for the treatment of myelodysplastic syndrome and are being evaluated in gynecological neoplasias.

AREAS COVERED

We provide an overview of the current knowledge on DNA methylation and cancer and the role of DNA methylation in cervical, ovarian and endometrial carcinomas. The results of recent clinical trials with demethylating agents for cervical and ovarian cancer treatment are also discussed.

EXPERT OPINION

There are few studies of DNA demethylating agents for cervical and ovarian cancer treatment; nevertheless, the results are promising. To accelerate these advances, there are at least two actions that can be simultaneously pursued. One is to greatly increase the number of small clinical exploratory trials with existing demethylating drugs and using methylome analyses to identify predictive factors for response and/or toxicity. The second is finding out epigenetic 'drivers' unique to gynecological cancers and their subtypes, and then proceed to clinical trials in a highly selected population of patients. It is expected that in the future, DNA demethylation could have a role in the treatment of gynecologic cancers.

New molecular targets against cervical cancer

Cervical cancer is the third most commonly diagnosed cancer worldwide and the fourth leading cause of cancer death in women. Major advances but still insufficient achievements in the treatment of locally advanced and high-risk early stage patients have occurred in the last decade with the incorporation of concurrent cisplatin with radiation and, lately, gemcitabine added to cisplatin chemoradiation. Despite a number of clinical studies incorporating molecular-targeted therapy as radiosensitizers being in progress, so far, only antiangiogenic therapy with bevacizumab added to cisplatin chemoradiation has demonstrated safety and shown encouraging results in a Phase II study. In advanced disease, cisplatin doublets do not have a great impact on the natural history of the disease with median survival rates not exceeding 13 months. The first Phase III study of bevacizumab, added to cisplatin or a non-cisplatin-containing doublet, showed significant increase in both overall survival and progression-free survival. Further studies are needed before bevacizumab plus chemotherapy can be considered the standard of care for advanced disease. Characterization of the mutational landscape of cervical cancer has already been initiated, indicating that, for now, few of these targetable alterations match with available agents. Progress in both the mutational landscape knowledge and developments of novel targeted therapies may result in more effective and individualized treatments for cervical cancer. The potential efficacy of knocking down the key alterations in cervical cancer – E6 and E7 human papillomavirus oncoproteins – must not be overlooked.

DNA methylation-independent reversion of gemcitabine resistance by hydralazine in cervical cancer cells

Background

Down regulation of genes coding for nucleoside transporters and drug metabolism responsible for uptake and metabolic activation of the nucleoside gemcitabine is related with acquired tumor resistance against this agent. Hydralazine has been shown to reverse doxorubicin resistance in a model of breast cancer. Here we wanted to investigate whether epigenetic mechanisms are responsible for acquiring resistance to gemcitabine and if hydralazine could restore gemcitabine sensitivity in cervical cancer cells.

Methodology/Principal Findings

The cervical cancer cell line CaLo cell line was cultured in the presence of increasing concentrations of gemcitabine. Down-regulation of hENT1 & dCK genes was observed in the resistant cells (CaLoGR) which was not associated with promoter methylation. Treatment with hydralazine reversed gemcitabine resistance and led to hENT1 and dCK gene reactivation in a DNA promoter methylation-independent manner. No changes in HDAC total activity nor in H3 and H4 acetylation at these promoters were observed. ChIP analysis showed H3K9m2 at hENT1 and dCK gene promoters which correlated with hyper-expression of G9A histone methyltransferase at RNA and protein level in the resistant cells. Hydralazine inhibited G9A methyltransferase activity in vitro and depletion of the G9A gene by iRNA restored gemcitabine sensitivity.

Conclusions/Significance

Our results demonstrate that acquired gemcitabine resistance is associated with DNA promoter methylation-independent hENT1 and dCK gene down-regulation and hyper-expression of G9A methyltransferase. Hydralazine reverts gemcitabine resistance in cervical cancer cells via inhibition of G9A histone methyltransferase.

Second hit in cervical carcinogenesis process: involvement of wnt/beta catenin pathway

The Human papillomavirus plays an important role in the initiation and progression of cervical cancer. However, it is a necessary but not sufficient cause to develop invasive carcinoma; hence, other factors are required in the pathogenesis of this malignancy. In this review we explore the hypothesis of the deregulation of wnt/beta-catenin signaling pathway as a "second hit" required to develop cervical cancer.

Valproic acid as epigenetic cancer drug: preclinical, clinical and transcriptional effects on solid tumors

Among many anticancer drugs collectively named "targeted or molecular therapies" epigenetic drugs are clearly promising. Differently from other agents targeting a single gene product, epigenetic drugs have chromatin as their target through inhibition of histone deacetylases (HDACs) and DNA methyltransferases (DNMTs) therefore, yet unspecific, they may act upon most or all tumor types, as deregulation of the methylation and deacetylation machinery are a common hallmark of neoplasia. In the last years, valproic acid (VPA) as emerged as a promising drug for cancer treatment. VPA has shown potent antitumor effects in a variety of in vitro and in vivo systems, and encouraging results in early clinical trials either alone or in combination with demethylating and/or cytotoxic agents. In addition, whole genome expression by microarray analysis from the primary tumors of patients treated with VPA show significant up-regulation of hundred of genes belonging to multiple pathways including ribosomal proteins, oxidative phosphorylation, MAPK signaling; focal adhesion, cell cycle, antigen processing and presentation, proteasome, apoptosis, PI3K, Wnt signaling, calcium signaling, TGF-beta signaling, and ubiquitin-mediated proteolysis among others. Despite in general, industry is not particularly interested in funding the clinical development of VPA, -at least in comparison to novel HDAC inhibitors-, existing preclinical and preliminary clinical data strongly suggest that VPA could be a drug that eventually will be used in combination therapies, either with classical cytotoxics, other molecular-targeted drugs or radiation in a number of solid tumors.

Tamoxifen-associated vasculitis in a breast cancer patient

Background

Estrogen plays a critical role in breast cancer. Thereafter, endocrine therapy is a standard of care in patients with breast carcinoma, expressing ER or PR.

Case presentation

Herein we report the case of a 53-year old patient, who developed cholestasis and vasculitis during the treatment with tamoxifen. This toxicity was reversable after the removal of the drug. Thereafter she continued adjuvant treatment for breast carcinoma with anastrazole. Since tamoxifen has been widely indicated for patients with breast carcinoma, we did a literature review, looking for other cases with this type of toxicity.

Conclusion

This case is the third with vasculitis informed in the literature, but the first one that additionally developed cholestasis and arthritis. Although it is rare, we discuss the indication of this drug in the actual era, where aromatase inhibitors offer a better security profile.

Radiation-sparing managements for cervical cancer: a developing countries perspective

Cervical cancer is the seventh most frequent cancer worldwide but more than 80% of cases occur in developing countries. Till date, radiation therapy with external beam and brachytherapy remains as the core treatment for most stages of cervical cancer. However, radiation treatment protocols and equipment modelled on the best developed countries can be seldom applied directly to developing countries owing to financial constraints and lack of qualified personnel, thus, a substantial proportion of patients do not have access to even palliative radiation therapy. Treatment options when the standard therapy is either not available or difficult to reproduce in particular settings is highly desirable with the potential to save lives that otherwise could be lost by the lack of adequate treatment. These options of treatment ideally had to have show, 1) that these are not inferior to the "standard" in terms of either survival or quality of life; 2) that these can be delivered in settings were the "standard" is not available or if available its quality is poor; and 3) that the treatment option be accepted by the population to be treated.

Based on these considerations, it is obvious that cervical cancer patients, particularly those who live in countries with limited resources and therefore may not have sufficient radiation therapy resources are in need of newer therapeutical options. There is now a considerable amount of information emanating from clinical studies where surgery has a major role in treating this disease. These forms of "radiation-sparing" treatments include total mesometrial resection that could make unnecessary the use of adjuvant radiation; neoadjuvant chemotherapy that could avoid the use of adjuvant radiation in around 85% of patients and preoperative chemoradiation that could make brachytherapy dispensable. The feasibility and therapeutical value of these potential forms of management need to be prospectively evaluated.

Can the state of cancer chemotherapy resistance be reverted by epigenetic therapy?

BACKGROUND

Transcriptome analysis shows that the chemotherapy innate resistance state of tumors is characterized by: poorly dividing tumor cells; an increased DNA repair; an increased drug efflux potential by ABC-transporters; and a dysfunctional ECM. Because chemotherapy resistance involves multiple genes, epigenetic-mediated changes could be the main force responsible of this phenotype. Our hypothesis deals with the potential role of epigenetic therapy for affecting the chemotherapy resistant phenotype of malignant tumors.

PRESENTATION OF THE HYPOTHESIS

Recent studies reveal the involvement of DNA methylation and histone modifications in the reprogramming of the genome of mammalian cells in cancer. In this sense, it can be hypothesized that epigenetic reprogramming can participate in the establishment of an epigenetic mark associated with the chemotherapy resistant phenotype. If this were correct, then it could be expected that agents targeting DNA methylation and histone deacetylation would by reverting the epigenetic mark induce a global expression profile that mirror the observed in untreated resistant cells.

TESTING THE HYPOTHESIS

It is proposed to perform a detailed analysis using all the available databases where the gene expression of primary tumors was analyzed and data correlated with the therapeutic outcome to determine whether a transcriptome profiling of "resistance" is observed. Assuming an epigenetic programming determines at some level the intrinsic resistant phenotype, then a similar pattern of gene expression dictated by an epigenetic mark should also be found in cell acquiring drug resistance. If these expectations are meet, then it should be further investigated at the genomic level whether these phenotypes are associated to certain patterns of DNA methylation and chromatin modification. Once confirmed the existence of an epigenetic mark associated to either the intrinsic or acquired chemotherapy resistant phenotype, then a causal association should be investigated. These preclinical findings should also be tested in a clinical setting.

IMPLICATIONS OF THE HYPOTHESIS

Our hypothesis on the ability of epigenetic therapy to revert the epigenetic changes leading to a transcritome profile that defines the resistant state will eventually be a more rational and effective way to treat malignant tumors.

Polymorphisms of the thiopurine S-methyl transferase gene (TMPT) in a Mexican population

20049

Background: Polymorphisms at the thiopurine S-methyltransferase coding gene (TPMT) determine enzyme activity and as a consequence the development of toxicity of thiopurine drugs. Methods: To test the frequency of polymorphisms of TPMT gene in Mexican population. 36 DNA samples from volunteer donors were analyzed. Genomic DNA from peripheral leukocytes was isolated by standard methods. Known (wild type and polymorphic) sequenced PCR fragments of the TPMT gene were used used as controls. PCR amplification: Fragments of the TPMT gene were amplified using the following oligonucleotides primers: Exon 5: 5′-CTGCATGTTCTTTGAAACCCTATGAA-3′ and 5′-CTTGAGGACAGAGAGGCTTTGACCTC-3′; exon 7: 5′-CTCCACACCCAGGTCC-ACACATT-3′ and 5′-GTATAGTACTAAAAAATTAAGACAGCTAAAC-3′; exon 10: 5′-AATCCTGATGTCATTCTTCATAGTATTT-3′ and 5′-CATCCATTACATTTTCAGG-CTTTAGCATAAT-3′. PCR products were then analyzed by denaturating high performance liquid chromatography (DHPLC) for the most frequent mutant TPMT alleles, according to the method developed by Schaeffeler et al (Clin Chem 2001; 47: 548) on an analysis system from Transgenomics Results: A high frequency of gene polymorphisms was identified, particularly in the exon 7 (14/36 = 38%), followed by exon 10 (3/36 = 8.3%) and 5 (2/36 = 5.5%). After analysing the three exons, the presence of mutations discriminating for TPMT alleles showed that 7/36 (19.4 %) were silent and located at T474C, in exon 7 (*1S) and 7/36 (19.4 %) were functional, and located in TPMT alleles *2 (2/36 = 5.5%), *3B (2/36 = 5.5%), *4 (2/36 = 5.5%) and *3B/4 (1/36= 2.7%). Conclusions: This is the first analysis of the polymorphisms at this gene in a Mexican population. The frequency of known silent polymorphisms was higher than those reported in other world regions but the frequency of functional polymorphism is within the range found in other reports. DHPLC is a highly sensitive, rapid and efficient method to identify relevant TPMT gene mutations which allows the screening for genetic variability in the TPMT gene . This trial was supported by a grant of CONACYT.

No significant financial relationships to disclose.

Antineoplastic effects of the DNA methylation inhibitor hydralazine and the histone deacetylase inhibitor valproic acid in cancer cell lines

Background

Among the epigenetic alterations occurring in cancer, DNA hypermethylation and histone hypoacetylation are the focus of intense research because their pharmacological inhibition has shown to produce antineoplastic activity in a variety of experimental models. The objective of this study was to evaluate the combined antineoplastic effect of the DNA methylation inhibitor hydralazine and the histone deacetylase inhibitor valproic acid in a panel of cancer cell lines.

Results

Hydralazine showed no growth inhibitory effect on cervical, colon, breast, sarcoma, glioma, and head & neck cancer cell lines when used alone. On the contrary, valproic acid showed a strong growth inhibitory effect that is potentiated by hydralazine in some cell lines. Individually, hydralazine and valproic acid displayed distinctive effects upon global gene over-expression but the number of genes over-expressed increased when cells were treated with the combination. Treatment of HeLa cells with hydralazine and valproic acid lead to an increase in the cytotoxicity of gemcitabine, cisplatin and adriamycin. A higher antitumor effect of adriamycin was observed in mice xenografted with human fibrosarcoma cells when the animals were co-treated with hydralazine and valproic acid.

Conclusion

Hydralazine and valproic acid, two widely used drugs for cardiovascular and neurological conditions respectively have promising antineoplastic effects when used concurrently and may increase the antitumor efficacy of current cytotoxic agents.

Response to gefitinib in bronchioloalveolar carcinoma in the absence of EGFR mutation

Mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene in non-small cell lung cancers are associated with increased sensitivity of these cancers to drugs that inhibit EGFR kinase activity such as gefitinib and erlotinib. Responses to TK inhibitors in the absence of EGFR gene mutation for BAC patients have not been reported. A case of a patient with BAC refractory to chemotherapy who responded to gefitinib in the absence of EGFR gene mutations is reported. Tyrosine kinase inhibitors may have a role in BAC in the absence of EGFR gene mutations. Additional studies on other molecular alterations of the EGFR family members are needed to better predict response to these agents.

Pre-exenterative chemotherapy, a novel therapeutic approach for patients with persistent or recurrent cervical cancer

Background

Most cervical cancer patients with pelvic recurrent or persistent disease are not candidates for exenteration, therefore, they only receive palliative chemotherapy. Here we report the results of a novel treatment modality for these patients pre-exenterative chemotherapy- under the rational that the shrinking of the pelvic tumor would allow its resection.

Methods

Patients with recurrent or persistent disease and no evidence of systemic disease, considered not be candidates for pelvic exenteration because of the extent of pelvic tumor, received 3-courses of platinum-based chemotherapy. Response was evaluated by CT scan and bimanual pelvic examination; however the decision to perform exenteration relied on the physical findings. Toxicity to chemotherapy was evaluated with standard criteria. Survival was analyzed with the Kaplan-Meier method.

Results

Seventeen patients were studied. The median number of chemotherapy courses was 4. There were 9 patients who responded to chemotherapy, evaluated by bimanual examination and underwent pelvic exenteration. Four of them had pathological complete response. Eight patients did not respond and were not subjected to surgery. One patient died due to exenteration complications. At a median follow-up of 11 months, the median survival for the whole group was 11 months, 3 months in the non-operated and 32 months in those subjected to exenteration.

Conclusion

Pre-exenterative chemotherapy is an alternative for cervical cancer patients that are no candidates for exenteration because of the extent of the pelvic disease. Its place in the management of recurrent disease needs to be investigated in randomized studies, however, its value for offering long-term survival in some of these patients with no other option than palliative care must be stressed.

A clinical and biological overview of gastrointestinal stromal tumors

In the last few years a body of knowledge has been generated on the molecular basis of gastrointestinal stromal tumors (GIST). These mesenchymal tumors are characterized by the expression of KIT protein and because they have an activating mutation in a class III receptor tyrosine kinase gene (KIT or PDGFRA). Several KIT-activating mutations, which are largely responsible for the development of this tumor, promote cell survival, proliferation, and migration through different pathways such as MAPK p42/44, AKT, S6K, STAT1, and STAT3. Likewise, gene-activating mutations in the gene PDGFRalpha which codes for the receptor tyrosine kinase, Platelet-derived growth factor receptor alpha have been identified in GIST lacking KIT mutations. This means that KIT and PDGFRalpha mutations appear to be alternative and mutually exclusive oncogenic pathways for GIST development. These tumors may occur anywhere along the gastrointestinal tract (GI). The most frequently involved sites are stomach and small intestine. They are typically chemo- and radioresistant. The discovery of a specific inhibitor of this tyrosine kinase, imatinib mesylate, has radically changed the prognosis of patients with unresectable disease. Only 4 yr after the first patient was successfully treated with imatinib, multiple phase II and III trials have been published and, currently, imatinib mesylate is the only effective systemic treatment available of these tumors. Response rates are approximately 70-90% with acceptable toxicity. GIST are the first model of a solid tumor efficiently treated with a molecular-targeted agent. This review summarizes the clinical and biological aspects of this unique neoplasm.

Histone acetylation and histone deacetylase activity of magnesium valproate in tumor and peripheral blood of patients with cervical cancer. A phase I study

BACKGROUND

The development of cancer has been associated with epigenetic alterations such as aberrant histone deacetylase (HDAC) activity. It was recently reported that valproic acid is an effective inhibitor of histone deacetylases and as such induces tumor cell differentiation, apoptosis, or growth arrest.

METHODS

Twelve newly diagnosed patients with cervical cancer were treated with magnesium valproate after a baseline tumor biopsy and blood sampling at the following dose levels (four patients each): 20 mg/kg; 30 mg/kg, or 40 mg/kg for 5 days via oral route. At day 6, tumor and blood sampling were repeated and the study protocol ended. Tumor acetylation of H3 and H4 histones and HDAC activity were evaluated by Western blot and colorimetric HDAC assay respectively. Blood levels of valproic acid were determined at day 6 once the steady-state was reached. Toxicity of treatment was evaluated at the end of study period.

RESULTS

All patients completed the study medication. Mean daily dose for all patients was 1,890 mg. Corresponding means for the doses 20-, 30-, and 40-mg/kg were 1245, 2000, and 2425 mg, respectively. Depressed level of consciousness grade 2 was registered in nine patients. Ten patients were evaluated for H3 and H4 acetylation and HDAC activity. After treatment, we observed hyperacetylation of H3 and H4 in the tumors of nine and seven patients, respectively, whereas six patients demonstrated hyperacetylation of both histones. Serum levels of valproic acid ranged from 73.6-170.49 microg/mL. Tumor deacetylase activity decreased in eight patients (80%), whereas two had either no change or a mild increase. There was a statistically significant difference between pre and post-treatment values of HDAC activity (mean, 0.36 vs. 0.21, two-tailed t test p < 0.0264). There was no correlation between H3 and H4 tumor hyperacetylation with serum levels of valproic acid.

CONCLUSION

Magnesium valproate at a dose between 20 and 40 mg/kg inhibits deacetylase activity and hyperacetylates histones in tumor tissues.

Serum nucleosomes during neoadjuvant chemotherapy in patients with cervical cancer. Predictive and prognostic significance

Background

It has been shown that free DNA circulates in serum plasma of patients with cancer and that at least part is present in the form of oligo- and monucleosomes, a marker of cell death. Preliminary data has shown a good correlation between decrease of nucleosomes with response and prognosis. Here, we performed pre- and post-chemotherapy determinations of serum nucleosomes with an enzyme-linked immunosorbent assay (ELISA) method in a group of patients with cervical cancer receiving neoadjuvant chemotherapy.

Methods

From December 2000 to June 2001, 41 patients with cervical cancer staged as FIGO stages IB2-IIIB received three 21-day courses of carboplatin and paclitaxel, both administered at day 1; then, patients underwent radical hysterectomy. Nucleosomes were measured the day before (baseline), at day seven of the first course and day seven of the third course of chemotherapy. Values of nucleosomes were analyzed with regard to pathologic response and to time to progression-free and overall survival.

Results

All patients completed chemotherapy, were evaluable for pathologic response, and had nucleosome levels determined. At a mean follow-up of 23 months (range, 7–26 months), projected progression time and overall survival were 80.3 and 80.4%, respectively. Mean differential values of nucleosomes were lower in the third course as compared with the first course (p >0.001). The decrease in the third course correlated with pathologic response (p = 0.041). Survival analysis showed a statistically significant, better progression-free and survival time in patients who showed lower levels at the third course (p = 0.0243 and p = 0.0260, respectively). Cox regression analysis demonstrated that nucleosome increase in the third course increased risk of death to 6.86 (95% confidence interval [CI 95%], 0.84–56.0).

Conclusion

Serum nucleosomes may have a predictive role for response and prognostic significance in patients with cervical cancer patients treated with neoadjuvant chemotherapy.

A phase I study of carboplatin concurrent with radiation in FIGO stage IIIB cervix uteri carcinoma

PURPOSE

Chemoradiation based on cisplatin, most commonly weekly, is the standard treatment of locally advanced cervical cancer; however, the nephrotoxic potential and the requirement for hydration of cisplatin somewhat restrains its use. The objective of this study was to determine the recommended dose of carboplatin when administered weekly during pelvic radiation (RT).

METHODS AND MATERIALS

Twenty-four histologically proven, International Federation of Gynecology and Obstetrics Stage IIIB patients were treated with standard pelvic RT concurrently with six weekly applications of carboplatin at the following dose levels: 100 mg/m(2), 116 mg/m(2), 133 mg/m(2), and 150 mg/m(2). Six patients per level were treated. Acute toxicity was assessed according to the Radiation Therapy Oncology Group Acute Radiation Morbidity Scoring Criteria. The recommended dose was defined as the one that was one level below the level at which dose-limiting toxicity was present in more than one-third of patients.

RESULTS

Between September 2001 and July 2002, 24 patients were accrued. All but two completed external beam radiotherapy and intracavitary treatment. The treatment was well tolerated. The median number of weekly applications of carboplatin was six, and the mean dose to points A and B was 85.6 Gy (range 75.2-91.6) and 62.9 Gy (range 58.2-74.6), respectively. RT was delivered within 41.7 days (range 33-70). Dose-limiting toxicity (leukopenia and/or neutropenia) was present in 50% of patients treated at the higher dose level (150 mg/m(2)). At the recommended dose of 133 mg/m(2), 33% of patients presented with Grade 3 leukopenia. At treatment completion, 75% of patients had a complete clinical response.

CONCLUSION

Carboplatin at 133 mg/m(2), weekly for 6 weeks, is a well tolerated and effective radiosensitizer in cervical cancer patients.

Concomitant chemoradiation versus neoadjuvant chemotherapy in locally advanced cervical carcinoma: results from two consecutive phase II studies

BACKGROUND

Randomized studies comparing induction chemotherapy followed by surgical resection with radiation alone found that the neoadjuvant approach produces better results. So far, this latter modality has not been compared with standard concomitant chemoradiation. The objective of this report was to compare the results of two consecutive phase II studies: neoadjuvant chemotherapy followed by surgery or chemoradiation for the unresectable cases versus standard cisplatin-based chemoradiation.

PATIENTS AND METHODS

From February 1999 to July 1999, 41 patients with cervical carcinoma, stages IB2-IIIB, were treated with neoadjuvant chemotherapy. Treatment consisted of three 21-day courses of cisplatin 100 mg/m(2) on day 1 and gemcitabine 1000 mg/m(2) on days 1 and 8, followed by either surgery or concomitant chemoradiation for the non-operable cases. From August 1999 to December 1999, an equal number of patients having comparable clinicopathological characteristics were treated with six weekly courses of cisplatin 40 mg/m(2) during standard pelvic radiation.

RESULTS

A total of 82 patients were analyzed. Both groups were similar with regard to age, histology, International Federation of Gynecology and Obstetrics (FIGO) stage, tumor size, pretreatment hemoglobin levels, parametrial infiltration and performance status. In the neoadjuvant arm the overall response rate to induction chemotherapy was 95% (95% confidence interval 88% to 100%). Twenty-three patients had surgery and 14 underwent chemoradiation. In the definitive chemoradiation study, 38 patients completed treatment, the median number of cisplatin courses was six for a dose intensity of 33 mg/m(2)/week. Doses to points A and B were 85 Gy (range 68-95) and 55 Gy (range 51-65), respectively. Chemoradiation was delivered in 44.6 (range 28-113) days. Complete response rates after all treatment were similar: 97% and 87% in the neoadjuvant and chemoradiation groups, respectively. At a median follow-up of 28 (range 2-33) and 24 (range 3-30) months, respectively, there were no differences in overall survival. To date, 15 and 13 patients in the neoadjuvant and chemoradiation groups, respectively, have died of disease (P = 0.8567).

CONCLUSIONS

The results of this non-randomized comparison suggest that induction chemotherapy followed by surgery or chemoradiation is at least as effective in terms of response and survival as standard cisplatin-based chemoradiation. A randomized study is needed to confirm these findings.