Molecular Mechanisms Involved In The Acquisition Of Resistance To Treatment Of Colon Cancer Cells

Cancer cells are remarkably resilient to therapies aimed at their elimination. The exploration of pathways that sustain cancer cells and that allow cancer cells to become resistant has revealed new avenues for chemotherapeutic development, as well as rational approaches to combination therapies based on existing treatment options. Several signaling pathways, such as Wnt, phosphoinositide 3-kinase (PI3K), and Ras-Raf-MEK, constitute integrated networks that work together to maintain cellular homeostasis under basal conditions and to drive cell-mass accumulation and cell cycle progression in the presence of appropriate mitogenic stimuli. During cancer development, these pathways are corrupted in malignant cells to maintain viability and proliferative activity under environmentally stressful conditions such as limited growth factors, oxygen, and nutrients that drive normal cells into quiescence or death. Importantly, dysfunction within any one of these pathways results in compensatory responses from the other networks. Thus, biological research is gradually shifting toward more general approaches that target entire pathways rather than isolated components and integrate those pathways into biological networks.

Drug Resistance in Colorectal Cancer: Molecular Mechanisms and Therapeutic Strategies, Volume Eight, summarizes the molecular mechanisms of drug resistance in colorectal cancer, along with the most up-to-date therapeutic strategies available. The book discusses reasons why colorectal tumors become refractory during the progression of the disease, but also explains how drug resistance occurs during chemotherapy. In addition, users will find the current therapeutic strategies used by clinicians in their practice in treating colorectal cancer. The combination of conventional anticancer drugs with chemotherapy-sensitizing agents plays a pivotal role in improving the outcome of colorectal cancer patients, in particular those with drug-resistant cancer cells. From a clinical point-of-view, the content of this book provides clinicians with updated therapeutic strategies for a better choice of drugs for drug-resistant colorectal cancer patients. It will be a valuable source for cancer researchers, oncologists and several members of biomedical field who are dedicated to better treat patients with colorectal cancer. Presents a systemic summary of molecular mechanisms for a quick and in-depth understanding Updates current trends in the field with pioneering information on drug resistance Encompasses both basic and clinical approaches for a better understanding of unsolved problems from a holistic point-of-view

Chemotherapy is one of the major treatment options for cancer patients; however, the efficacy of chemotherapeutic management of cancer is severely limited by multidrug resistance, in that cancer cells become simultaneously resistant to many structurally and mechanistically unrelated drugs. In the past three decades, a number of mechanisms by which cancer cells acquire multidrug resistance have been discovered. In addition, the development of agents or strategies to overcome resistance has been the subject of intense study. This book contains comprehensive and up-to-date reviews of multidrug resistance mechanisms, from over-expression of ATP-binding cassette drug transporters such as P-glycoprotein, multidrug resistance-associated proteins, and breast cancer resistance p- tein to the drug ratio-dependent antagonism and the paradigm of cancer stem cells. The book also includes strategies to overcome multidrug resistance, from the development of compounds that inhibit drug transporter function to the modulation of transporter expression. In addition, this book contains techniques for the detection and imaging of drug transporters, methods for the investigation of drug resistance in animal models, and strategies to evaluate the efficacy of resistance reversal agents. The book intends to provide a state-of-the-art collection of reviews and methods for both basic and clinician investigators who are interested in cancer multidrug resistance mechanisms and reversal strategies. Tianjin, China Jun Zhou v Contents Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Contributors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix 1 Multidrug Resistance in Cancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Bruce C. Baguley 2 Multidrug Resistance in Oncology and Beyond: From Imaging of Drug Efflux Pumps to Cellular Drug Targets . . . . . . . . . . . . . . . . . . . . . . . . . .

30 years after its discovery as an antitumor agent, cisplatin represents today one of the most successful drugs in chemotherapy. This book is intended to reminisce this event, to take inventory, and to point out new lines of development in this field. Divided in 6 sections and 22 chapters, the book provides an up-to-date account on topics such as - the chemistry and biochemistry of cisplatin, - the clinical status of Pt anticancer drugs, - the impact of cisplatin on inorganic and coordination chemistry, - new developments in drug design, testing and delivery. It also includes a chapter describing the historical development of the discovery of cisplatin. The ultimate question - How does cisplatin kill a cell? - is yet to be answered, but there are now new links suggesting how Pt binding to DNA may trigger a cascade of cellular reactions that eventually result in apoptosis. p53 and a series of damage recognition proteins of the HMG-domain family appear to be involved. The book addresses the problem of mutagenicity of Pt drugs and raises the question of the possible relevance of the minor DNA adducts, e.g. of interstrand cross-links, and the possible use of trans-(NH3)2Pt(II)-modified oligonucleotides in antisense and antigene strategies. Our present understanding of reactions of cisplatin with DNA is based upon numerous model studies (from isolated model nucleobases to short DNA fragments) and application of a large body of spectroscopic and other physico-chemical techniques. Thanks to these efforts there is presently no other metal ion whose reactions with nucleic acids are better understood than Pt. In a series of chapters, basic studies on the interactions of Pt electrophiles with nucleobases, oligonucleotides, DNA, amino acids, peptides and proteins are reported, which use, among others, sophisticated NMR techniques or X-ray crystallography, to get remarkable understanding of details on such reactions. Reactivity of cisplatin, once bound to DNA and formerly believed to be inert enough to stay, is an emerging phenomenon. It has (not yet) widely been studied but is potentially extremely important. Medicinal bioinorganic chemistry - the role of metal compounds in medicine - has received an enormous boost from cisplatin, and so has bioinorganic chemistry as a whole. There is hardly a better example than cisplatin to demonstrate what bioinorganic chemistry is all about: The marriage between classic inorganic (coordination) chemistry and the other life sciences - medicine, pharmacy, biology, biochemistry. Cisplatin has left its mark also on areas that are generally considered largely inorganic. The subject of mixed-valance Pt compounds is an example: From the sleeping beauty it made its way to the headlines of scientific journals, thanks to a class of novel Pt antitumor agents, the so-called "platinum pyrimidine blues". In the aftermath diplatinum (III) compounds were recognized and studies in large numbers, and now an organometalic chemistry of these diplatinum (III) species is beginning to emerge. The final section of the book is concerned with new developments such as novel di- and trinuclear Pt(II) drugs with DNA binding properties different from those of cisplatin, with orally active Pt(IV) drugs which are presently in clinical studies, and with attempts to modify combinatorial chemistry in such a way that it may become applicable to fast screening of Pt antitumor drugs. The potential of including computational methods in solving questions of Pt-DNA interactions is critically dealt with in the concluding chapter.

This volume examines in detail the role of chronic inflammatory processes in the development of several types of cancer. Leading experts describe the latest results of molecular and cellular research on infection, cancer-related inflammation and tumorigenesis. Further, the clinical significance of these findings in preventing cancer progression and approaches to treating the diseases are discussed. Individual chapters cover cancer of the lung, colon, breast, brain, head and neck, pancreas, prostate, bladder, kidney, liver, cervix and skin as well as gastric cancer, sarcoma, lymphoma, leukemia and multiple myeloma.

As the number of patients with colitis-associated cancer (CAC) is on the increase, the purpose of this book is to review the latest topics concerning management of the disease. In recent years, the diagnostic power of endoscopy and molecular pathology has also grown tremendously, as a result of which they now have a far greater influence on the treatment of CAC. At the moment, appropriate monitoring programs for ulcerative colitis and Crohn’s disease remain uncertain. At the same time, the latest findings on DNA methylation and microRNAs hold the promise of making revolutionary changes in these areas. Moreover, recent drug advances in the treatment of inflammatory bowel diseases have changed surgical indications. On the other hand, the indication of mucosectomy on colorectal cancer in ulcerative colitis and prophylactic abdominoperineal resection for Crohn’s disease remain controversial. This book provides the latest information on the remaining issues of CAC from the point of view of expert surgeons.

Colorectal cancer (CRC) is a major health problem because it represents around 10% of all cancers and achieves a worldwide estimate of 1.4 million newly diagnosed cases annually, resulting in approximately 700,000 deaths. Approximately 19-31% of patients present liver metastases. At diagnosis, a further 23-38% will develop extra-hepatic disease. Over the past decade, the widespread use of modern chemotherapeutic and biological agents, combined with laparoscopic surgical techniques, has improved the prognosis of metastatic CRC. A better understanding of the biology of the tumor, along with high efficiency of diagnostic and therapeutic methods, as well as the spread of screening programs, will improve the survival of the CRC patients in the near future.