がんの科学と治療

Clinicians should develop new hypotheses based on observations and interviews with patients, and basic researchers should go back to the bench to test compounds with anticipated anti-growth properties. Let’s not forget that the most popularly used anticancer agent, platinum, was discovered serendipitously when microbiologists were investigating the behavior of bacteria upon changes in voltage and observed growth inhibition due to electrolysis products from a platinum electrode. Hopefully, using all these resources, we will convert cancer into a treatable chronic disease. The current technological armamentarium provides cancer researchers with a unique opportunity to find new targets for old synthetic, abandoned compounds or newly discovered natural products.

The PI3K pathway is activated in a variety of human tumors including B-cell Non Hodgkin Lymphoma (B-NHL). Targeting this pathway has been validated in solid tumors, leukemia and lymphomas. SF1126, a novel pan-PI3K inhibitor designed by conjugating RGD peptide to LY294002 facilitates clinical testing of this prodrug, suppresses growth and survival of multiple solid tumors in vitro and in vivo. In this study, we demonstrated SF1126 had potent activity in a panel of aggressive B-NHL cell lines. Cells treated with SF1126 exhibited decreased phosphorylation of Akt and GSK-3β confirming the mechanism of action of a PI3K inhibitor. Also, treatment of B-NHL cell lines with SF1126 induced apoptosis in a dose-dependent manner and inhibited cell proliferation with an IC50 < 4 μM. However, the selective p110δ inhibitor, CAL-101 was less potent in inducing apoptosis and inhibiting cell proliferation compared to SF1126. Moreover, SF1126 induced G1 cell cycle arrest significantly at low concentrations which contributed to suppression of cell proliferation and corroborated to a decrease in cyclin D1. Finally, rituximab enhanced apoptosis induced by SF1126 and CAL-101. Taken together, our findings provide for the first time that SF1126 inhibits the constitutively activated PI3K/Akt pathway in aggressive B-cell NHL cell lines with associated inhibition of cell cycle progression, cell proliferation and promotion of apoptosis. These findings suggest that SF1126 is a novel therapeutic strategy in aggressive B-cell NHL and warrants early phase clinical trial evaluation ± rituximab.

Breast Cancer Stem (BCS) cells play critical roles in self-renewal, Multi Drug Resistance (MDR), differentiation and generation of secondary tumors. Conventional chemotherapy may efficiently kill the bulk of differentiated drug sensitive breast cancer cells, but not the MDR self-renewable BCS cells, leading to enrichment of the MDR BCS cells. In order to target the MDR BCS cells, we have isolated: 1) BCS cells from either breast cancer cell lines or fresh breast cancer specimens; 2) ATP binding cassette (ABC) transporter group G number 2 (ABCG2)-specific aptamers; and 3) BCS cell-binding aptamers. Interestingly, ABCG2-specific aptamers labeled the membrane surface of the ABCG2-expressing baby hamster kidney (BHK) cells, but stained whole cells of the BCS cells derived from mammospheres, implying that BCS cells might have much higher rate of endocytosis than the ABCG2-expressing BHK cells. In addition, 5D3, a monoclonal antibody that recognizes the extracellular loops of ABCG2 protein, also stained whole BCS cells. Furthermore, BCS cell-binding aptamers stained whole BCS cells, but not the differentiated breast cancer MCF-7 cells. All these results support above conclusion that BCS cells might have high rate of endocytosis. Further experiments performed with aptamers and human transferrin or lactosylceramide showed that BCS cells do have much higher endocytosis rate than the differentiated breast cancer cells. Interestingly, clathrin dependent endocytosis inhibitors, such as monodansylcadaverine or sucrose, or caveolin-dependent endocytosis inhibitors, such as methyl-β-cyclodextrin or genistein, can inhibit the internalization of transferrin or lactosylceramide into the differentiated breast cancer cells, but cannot block the internalization of these compounds into the BCS cells, suggesting that BCS cells undergo clathrin-independent and caveolinindependent endocytosis. Taken together, our data suggest that BCS cells have high rate of endocytosis and open the possibilities for delivering therapeutic agents directly into the MDR BCS cells with aptamer-coated liposomes.

Background: The combination of mitomycin C and cisplatin was proved to be beneficial in the treatment of lung cancer, breast cancer, anal carcinoma and human cervical cancer treatment. However, dose related toxicity happens to be one of the major concerns the treatment, leading to its discontinuation, although the patient’s response is encouraging. The aim of the present investigation was to study the protective effects of Berberis aristata (10 mg/kg body weight) on the mitochondrial dysfunction caused due to administration of mitomycin C (2 mg/kg body wt, i.p) and cisplatin (12 mg/kg body wt, i.p).

Methods: We have investigated the effects and protective effects on oxidative phosphorylation enzymes, of the electron transport system, lipid peroxidation and phospholipid composition in liver and kidney mitochondria.

Results: Co-administration of mitomycin C and cisplatin resulted in significant decrease in active respiration (State 3 Respiration), Respiratory Control Ratio (RCR) and P/O ratio’s using either succinate or glutamate plus malate as substrate. Altered enzyme activities of NADH dehydrogenase, succinate dehydrogenase, succinatecytochrome c reductase, NADH-cytochrome c reductase, cytochrome c oxidase was observed. The level of lipid peroxides was increased, and with a significant decrease in phospholipid content. Prior administration of Berberis aristata protected against observed mitochondrial dysfunction.

Conclusions: We believe that prior administration of Berberis aristata could reduce the damage to mitochondrial function, by scavenging free radicals and thereby, preventing uncoupling of oxidative phosphorylation, deactivation of enzymes of electron transport chain, generation of lipid peroxides, oxidation of phospholipids ultimately inhibiting the signaling wave propagation to the mitochondria death receptor (membrane bound cytochrome c), which generally leads to apoptosis.

We report two cases of renal cell carcinoma (RCC) that were amenable to surgical resection and cure 10 years after diagnosis. One of the cases was a 34 years old male who performed general duties in Army. He presented with left flank pain, fever, and loss of appetite of 10 days duration and on clinical examination, had a firm, non tender lump palpable in left lumbar region. The second case was 45 years old lady, a housewife, who presented with a large left flank lump. Further clinical and radiological evaluation revealed that the tumours were confined to Gerota’s fascia with no evidence of lymph node or distant metastasis in either of the cases. More importantly, both the patients were found to have been diagnosed with renal tumours ten years earlier as was evident from their past medical records and old imaging, although the tumour size was relatively smaller at that time. Both the patients, however, had defaulted from undergoing surgery. They underwent radical nephrectomy at our centre and histopathological examination revealed Furhmann Grade II clear renal cell carcinoma (Stage-T2bN0M0 in the first case and Stage-T3b N0 M0) in the second case. The first case has completed two years and the second case, one and half years, respectively, of follow up and is recurrence free. There is no other reported case of renal cell carcinoma in the published literature that were left untreated for ten years and still remained not only resectable but curable also.

Objective: To evaluate benefits of Recombinant Adeno-viral Human p53 (rAd-p53) gene therapy combined with radiotherapy in prevention of oral cancer recurrence after a radical resection. Methods: A total of 215 patients with resectable Tongue Cancer (TCa) and 268 patients with resectable Gingival Carcinoma (GCa) satisfying the inclusion criteria and were randomly assigned to two groups: the Experiment Group (EG) and the Control Group (CG). The EG received multi-point injections of rAd-p53 into the wound surface at a dose of 1 × 1012 Viral Particles (VP) after a radical resection. Both EG and CG were given radiotherapy at a total dose of 60 Gy three weeks after surgery. All these patients will be followed at least for 3 years. Results: Among these 483 cases, 107 patients (57 in EG and 50 in CG) finished 3-years follow-up. Two cases (2/27) of TCa and 2 (2/30) in GCa patients had a local recurrence in EG, but 8 (8/24) TCa and 8 (8/26) GCa patients in CG had a local recurrence. Both recurrent rates of TCa (33.3%) and GCa (30.8%) in CG are statistically significantly higher than that of TCa (7.4%) and GCa (6.7%) in EG, respectively. The overall recurrent rate in EG is 7.0%, which is also statistically significantly lower than that (32%) in CG. Overall 3-years survival (OS) rate of EG is 100% and the progress free survival (PFS) rate is 93.0% and the minimum PFS time is 29 months. The 3-years OS and PFS rates of CG are 94.0% and 68.0%, respectively. Except for self-limited fever, no other adverse reaction was found to be relative to rAd-p53. Conclusions: Post-tumorectomy wound surface injection of rAd-p53 combining with radiotherapy is safe, and may prevent local recurrence and increase both OS and PFS rate for the patients with TCa or GCa

Background: The p53 protein has pleiotropic functions in the modulation of genomic stability of cells. Disruption of p53 activity is commonly found in human cancers. The p53 codon 72 polymorphism is likely to play an important role in the susceptibility to OSCC. We aimed to investigate the association of p53 codon 72 polymorphism with oral squamous cell carcinoma in south Indian population.
 
Methods: We genotyped 150 OSCC patients and 150 controls, using PCR-RFLP method.
 
Results: Our results showed a significant difference in the distributions of p53 codon 72 genotypes among cases and controls. Genotype frequencies of p53 Arg/Arg, Arg/Pro and Pro/Pro were 50.8, 33.9 and 14.4% in the oral squamous cell carcinoma patients and 48.7, 45.1 and 6.2% in the controls, respectively. Arginine/arginine genotype was elevated in controls compared to patients (P<0.0001), where as Proline/Proline (P<0.005) and arginine/proline (P<0.002) genotypes were elevated in patients compared to controls. Arginine allele frequency showed high in cases than Proline.
 
Conclusion: The results of the present study detected that p53 codon 72 polymorphism may contribute to oral squamous cell carcinoma susceptibility in south Indian population.

Bronchiolitis Obliterans Syndrome (BOS) is a well-recognized complication of allogeneic Hematopoietic Stem Cell Transplantation (HSCT). The management of bronchiolitis obliterans has been frustrating, with patients developing progressive Air Flow Obstruction (AFO). The purpose of this study was to evaluate the efficacy of human Bone Marrow Derived Mesenchymal Stem Cells (BMMSC) as the salvage therapy for BOS after HSCT. One patient with BOS received intravenous infusions of BMMSC at a dose of 1.5×106/kg per patients’ weight, and rapid recovery from BOS without any side effects was observed. We concluded that BMMSC seems to be a promising therapeutic method in patients with BOS after HSCT.

Objectives: This study was designed to compare effectiveness of intra-pleural instillation of Bleomycin with instillation of Povidone-iodine for control of malignant pleural effusion among patients with non-small cell lung cancer, guided by results of thoracic Echography. Methods: Fifty one patients had the possibility of full lung expansion. Drainage of the effusion was followed by instillation of bleomycin or povidone- iodine through the thoracostomy tube. Four weeks after discharge, thoracic echography was performed and repeated 4 weeks later. Follow-up ranged between 4–32 months (mean: 21 ± 3.5 months). Results: We received 79 patients with malignant pleural effusion as stage IV non-small cell lung cancer during the last four years. Seventeen patients had centrally-located tumors with persistent lung atelectasis. Intrapleural injection of streptokinase to breakdown intra-pleural fibrinous adhesions was carried out in 9 cases; and was successful in 6 cases 66% (6/9). Finally, 54 patients had an evidence of possible lung expansion but three died before pleurodesis. Thus, 51 patients received intra-pleural instillation of bleomycin or povidone-iodine in a randomized prospective comparative study. Among bleomycin group (n = 26), echography showed excellent pleurodesis (n = 21), effective pleurodesis (n= 2) with one or two areas of free mobility and one area of fluid component, weak pleurodesis (no. = 3) with three areas of free lung movement (lung sliding sign) and areas of fluid component. Among povidone-iodine group (n= 25) excellent pleurodesis (no. = 20), effective (n= 2) and weak pleurodesis (n= 3). The six cases with weak pleurodisis in both groups were those who had streptokinase before pleurodesis. Complications and hospital stay were comparable for both groups. Chest X-ray proved recurrence of effusion in the six cases with weak pleurodesis after symptom-free intervals that varied between 4 and 6 weeks among these 6 patients. Conclusions: Both bleomycin and povidone-iodine produced comparable excellent and effective pleurodesis among patients with malignant pleural effusion. The cost is much lower with povidone-iodine.

Background: Tumor hypoxia is a common feature of various human malignancies. Hypoxia contributes to tumor progression, and is a major cause of tumor resistance to chemotherapy. Hypoxia-inducible factor (HIF)-1 is a key transcription factor in hypoxic responses, and regulates the transcription of genes that are involved in crucial aspects of cancer biology, including angiogenesis, cell survival, and invasion. We previously demonstrated that transcutaneous application of carbon dioxide (CO2) induced oxygenation in the treated tissue in vivo, therefore, we hypothesized that transcutaneous CO2 exposure could enhance the chemosensitivity by reducing hypoxia in a tumor tissue. The aim of this study was to examine the effect of oxygenation by transcutaneous application of CO2 on the therapeutic efficacy of doxorubicin (DOX) to treat human malignant fibrous histiocytoma (MFH) in vivo.

Methods: In this study, we utilized a murine model of human MFH, and mice were randomly divided into four groups: control, CO2, DOX and combination (CO2 + DOX) treatment groups to examine the effect of transcutaneous application of CO2 on the hypoxic condition, and to assess the therapeutic effect of combination therapy using transcutaneous CO2and DOX treatment in vivo.

Results: Transcutaneous application of CO2 treatment decreased HIF-1α expression in human MFH tumor tissues, suggesting that our transcutaneous CO2 treatment reduced the hypoxic conditions. Furthermore, transcutaneous CO2 treatment alone had an antitumoral effect, and increased the chemotherapeutic effect of DOX on MFH tumor growth in vivo, with no observable effects on body weight.

Conclusions: Our findings in this study strongly indicate that our transcutaneous CO2 system has antitumor effects and can enhance the chemosensitivity of tumor cells by reducing the local hypoxic conditions.