"Nano": the new nemesis of cancer.

Materials at nano dimensions exhibit totally different properties compared to their bulk and atomic states. This feature has been harnessed by scientists from various disciplines, to develop functional nanomaterials for cancer diagnosis and therapeutics. The success stories range from delivering chemotherapeutic molecules in nano-sized formulations to functional nanomaterials, which deliver thermal and radiotherapy at specific targeted sites. This brief review summarizes the recent developments of various nanotechnologies in cancer therapy and diagnostics, both from the research sector and the upcoming products in pipeline on its route to commercialization. Supportive engineering innovations and frontiers in nanomolecular research, with a potential to revolutionize cancer therapy, have been discussed in brief.

A new indication of sildenafil in medicine: hypoxic cell sensitizer for penile cancer.

PURPOSE: To evaluate the feasibility and results of sildenafil used as radiosensitizer by causing penile vasodilatation and reducing tumor hypoxia in radical radiotherapy for penile cancer. MATERIALS AND METHODS: Three men with histopathologic diagnosis of squamous carcinoma of penis were treated with radical external radiotherapy with concomitant sildenafil. Acute and late adverse events were noted according to RTOG toxicity criteria. Response to radiotherapy, as well as disease-free and overall survivals, was evaluated. RESULTS: All three patients achieved tumescence, completed the treatment and achieved complete response. One patient had recurrence at 10 months and died of the disease after 23 months from starting the treatment. Other two patients are disease-free and alive at 48 and 53 months respectively. No excess acute or late adverse event was observed. CONCLUSION: Sildenafil may act as radiosensitizer by causing penile vasodilatation and reducing hypoxia. Larger controlled studies are required to validate the hypothesis.

T2 weighted MRI in assessment of volume changes during radiotherapy of high grade gliomas.

AIM: To determine whether any changes in gross tumor volume occur between pre treatment MRI and week 5 MRI in high grade gliomas treated by conformal radiotherapy. METHODS AND MATERIALS: Between July 2003-July 2005, 17 patients with WHO grades 3 and 4 malignant gliomas treated with conformal radiotherapy to a total dose of 60 Gy were included in this retrospective study. All patients had undergone T2 weighted MRI a day before treatment and then again at end of week 5 of treatment for definition of initial and boost fields respectively. Gross tumor volumes were delineated on the two MRI's of each patient and the differences were noted. Two patients with multifocal disease were excluded from the final analysis. RESULTS: Of the 15 patients with unifocal disease, 12/15 cases (80%) showed a reduction in tumor volumes (median 54.85 cc). Of these, 4/15 (26.6%) cases (two each of grade 3 and grade 4 gliomas) had an objective reduction in GTV (> or = 50%) and 3/15 (20%) cases (two of grade 4 and one of grade 3 gliomas) demonstrated an increase in tumor volume (median 14 cc). CONCLUSIONS: This study has shown that a change in gross tumor volume occurred in almost all patients on week 5 MRI. The likelihood of treatment success would appear to be decreased if the tumour is not within the treatment field and hence it may be worthwhile to do a mid treatment MRI for definition of boost volumes especially in dose escalation trials employing highly conformal radiotherapy fields.

Surface activity, lipid profiles and their implications in cervical cancer.

BACKGROUND: The profiles of lipids in normal and cancerous tissues may differ revealing information about cancer development and progression. Lipids being surface active, changes in lipid profiles can manifest as altered surface activity profiles. Langmuir monolayers offer a convenient model for evaluating surface activity of biological membranes. AIMS: The aims of this study were to quantify phospholipids and their effects on surface activity of normal and cancerous human cervical tissues as well as to evaluate the role of phosphatidylcholine (PC) and sphingomyelin (SM) in cervical cancer using Langmuir monolayers. METHODS AND MATERIALS: Lipid quantification was done using thin layer chromatography and phosphorus assay. Surface activity was evaluated using Langmuir monolayers. Monolayers were formed on the surface of deionized water by spreading tissue organic phase corresponding to 1 mg of tissue and studying their surface pressure-area isotherms at body temperature. The PC and SM contents of cancerous human cervical tissues were higher than those of the normal human cervical tissues. Role of PC and SM were evaluated by adding varying amounts of these lipids to normal cervical pooled organic phase. Statistical analysis: Student's t-test (p < 0.05) and one-way analysis of variance (ANOVA) was used. RESULTS: Our results reveals that the phosphatidylglycerol level in cancerous cervical tissue was nearly five folds higher than that in normal cervical tissue. Also PC and sphingomyelin SM were found to be the major phospholipid components in cancerous and normal cervical tissues respectively. The addition of either 1.5 microg DPPC or 0.5 microg SM /mg of tissue to the normal organic phase changed its surface activity profile to that of the cancerous tissues. Statistically significant surface activity parameters showed that PC and SM have remarkable roles in shifting the normal cervical lipophilic surface activity towards that of cancerous lipophilic component. CONCLUSION: The Langmuir monolayer technique was sensitive to detect changes in tensiometric profiles of cervical cancers and these could be modulated by alterations in phosphatidylcholine and sphingomyelin levels. Therapeutic strategies may be designed to modulate these tensiometric profiles and lipid constituents of cancerous tissues.

Thermometry studies of radio-frequency induced hyperthermia on hydrogel based neck phantoms.

A cylindrical phantom, resembling average human neck, was prepared by using hydrogel sheets containing vinyl and polysaccharide. The phantom was used to obtain temperature distributions for 6 values of input power of radio frequency (RF) at 8MHz,by invasive thermometry technique, using thermistor probes.The inclusion of cervical vertebrae and calcium carbonate pieces (human bone representative) with a hollow tube (windpipe equivalent) in the phantom simulates the change in thermal distributions. This is similar to the alterations in heat disposition obtained in the real human neck, during RF induced heating, without extensive distortion of the uniform temperature distribution provided by the RF heating instrument.This paper compares the hydrogel neck phantom with other phantoms, that have been developed for studying thermal distributions and optimization of novel non invasive thermometry techniques in hyperthermic oncology.

Sanazole as a sensitizer of hypoxic cells with radical radiation in the treatment of advanced cancer of cervix an Indian experience.

AK-2123, is a nitrotriazole with a potential to sensitize hypoxic tissue to radiation. Cancer of cervix in advanced stages are predominantly treated with radiation. These are the tumours which harbour a large hypoxic core. This is an Indian experience of the multicentric trial. Patients were randomized to control and AK-2123 arm. 49 patients were randomized to each group. Patients received external radiation with telecobalt to a dose of 50 Gy in five weeks. Those in the study arm received 600 mg/m2, on alternate days. The patients were further treated with intracavitory radiation a dose of 20 Gy. The total dose of 70 Gy was achieved. Patients in the study arm had a complete response of 71.43% (35 of 49) while only 21 of 49 (42.86%) responded in the control group. The overall survival at two years was 72.2% for the study group and 32.43% for control. Neuropathy, a drug related toxicity was transient except, in one patient, which has persisted. AK-2123, has shown significant radiation sensitizing potential.