Tumour treatment

The Phototherapy of Cancer a Mode of Treatment Still at the Research Stage. Cancer is the uncontrolled proliferation of cells which build up into tumours. Treatments rely on the elimination of diseased cells, through surgery, through the effects of ionizing radiation or through chemicals. 

Tumour treatment with few side effects requires both encapsulation and targeted release of the cytostatic agent directly into the tumour cell. The latter can be accomplished by attaching the active ingredient via a covalent acid-labile bond because, in contrast to healthy tissue (pH 7.4), a relatively low pH value of ca. 5.5 is found in tumour cells (Fig. 8.20). 

Deterministic irradiation is applied in nuclear medicine for therapeutic purposes (chapter 19). For tumour treatment, large doses are delivered to selected tissues. Gamma rays emitted by °Co (up to 2 lO " Bq) or Cs (up to 2 lO Bq) are preferred for irradiation of deeply located organs. The doses transmitted to malignant tumours vary between about 10 and 100 Sv, and the individual responses of patients to certain radiation doses may vary appreciably. 

There seem few likely applications in therapeutics for bradykinin receptor agonists, though there are many putative applications for antagonists. However, the synthetic bradykinin B2 receptor agonist analogue RMP-7 is of some value for increasing cerebrovascular permeability in order to allow delivery to the brain of drugs that would otherwise not pass the blood-brain barrier (e.g. methotrexate and carboplatin in tumour treatment). 

O. Ben-Yoseph and B.D. Ross, Oxidation therapy the use of a reactive oxygen speciesgenerating enzyme system for tumour treatment, Br. J. Cancer, 70 (1994) 1131. 

Both singlet oxygen, 02( Ag), and radical intermediates are characterised by short lifetimes, are unstable and can react efficiently with cellular components such as proteins, lipids and DNA, thus causing irreversible damage to the affected cells. This damage leads to cell death through apoptosis or necrosis and results in eradication of unwanted tissues, e.g. cancerous lesions or unwanted vasculature (in tumour treatments or in AMD). 

R. Sailer, W.S.L. Strauss, Ft. Emmert, M. Wagner, R. Steiner, H. Schneckenburger, Photodynamic Efficacy and Spectroscopic Properties of 5-ALA Induced Protoporphyrin DC in Human Glioblastoma Cells, in Optical Methods for Tumour Treatment and Detection Mechanisms and Techniques in Photodynamic Therapy (D. Kessel, ed.), Proc. SPIE, Vol. 5689, Bellingham, USA, 2005, in press. 

Several of the naturally occurring indoles also have clinical importance. The dimeric vinca alkaloid vincristine and closely related compounds were among the first of the anti-mitotic class of chemotherapeutic agents for cancer[14]. The mitomycins[15] and derivatives of ellipticine[16] are other examples of compounds having anti-tumour activity. Reserpine, while not now a major drug, was one of the first compounds to show beneficial effects in treatment of mental disorders[17]... 

Most of the herbal drugs that are used medicinally are comprised in these five groups of indications. Relative few are employed in a limited number of other areas occasionally in skm remedies, liver remedies, coronary remedies, blood circulation remedies, and in other groups of medicines. Summarizing, it can be said that the possibilities of treatment with herbal drugs are limited for a number of reasons for a series of illnesses like severe cardiac insufficiency, tumours, infectious diseases, diabetes, etc., herbal drugs arc not adequate remedies, even though, in contravention of the law, such claims are made in many publications. In a series of further cases, they only find use in support of the actual medical treatment they are nevertheless of value. 

As endothelins mediate potent vasoconstrictor effects, ECE inhibitors and endothelin receptor antagonists were developed for the treatment of cardiovascular diseases, such as acute and chronic heart failure, pulmonary hypertension and subarachnoid haemorrhage. As ETa recqrtors have potent mitogenic responses and may promote progression of ovarian and prostate cancer and bone metastases ETA receptors are also considered as a potential targets for anti-tumour activity. 

The antisense oligonucleotide LErafAON against the serine/threonine kinase c-Raf has been tested in phase I clinical trials. The antisense oligonucleotides ISIS-5132, which also inhibits c-Raf, and ISIS-3521, which inhibits PKC, went through different phase clinical trials with solid tumour patients. Unfortunately, no objective responses occurred with these PKI. GEM-231, an oligonucleotide targeting the RIa subunit of protein kinase A is currently undergoing phase I/II clinical trials alone or in combination with traditional therapy for the treatment of solid cancers [3]. 

Tumour necrosis factor 157 amino acids E. coli Animal cells Treatment of cancer ... 

L-Asparaginase, an enzyme derived from E. coli or Erwinia carotovora, has been employed in cancer chemotherapy where its selectivity depends upon the essential requirement of some tumours for the amino acid L-asparagine. Normal tissues do not require this amino acid and thus the enzyme is administered with the intention of depleting tumour cells of asparagine by converting it to aspartic acid and ammonia. Whilst L-asparaginase showed promise in a variety of experimentally induced tumours, it is only useful in humans for the treatment of acute lymphoblastic leukaemia, although it is sometimes used for myeloid leukaemia. 

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