Effect of antineoplastic agents on smooth muscle cell proliferation in vitro: implications for prevention of restenosis after transluminal angioplasty

An integrative review of nonobvious puzzles of cellular and molecular cardiooncology

Oncologic patients are subjected to four major treatment types: surgery, radiotherapy, chemotherapy, and immunotherapy. All nonsurgical forms of cancer management are known to potentially violate the structural and functional integrity of the cardiovascular system. The prevalence and severity of cardiotoxicity and vascular abnormalities led to the emergence of a clinical subdiscipline, called cardiooncology. This relatively new, but rapidly expanding area of knowledge, primarily focuses on clinical observations linking the adverse effects of cancer therapy with deteriorated quality of life of cancer survivors and their increased morbidity and mortality. Cellular and molecular determinants of these relations are far less understood, mainly because of several unsolved paths and contradicting findings in the literature. In this article, we provide a comprehensive view of the cellular and molecular etiology of cardiooncology. We pay particular attention to various intracellular processes that arise in cardiomyocytes, vascular endothelial cells, and smooth muscle cells treated in experimentally-controlled conditions in vitro and in vivo with ionizing radiation and drugs representing diverse modes of anti-cancer activity.

Effects of 5-fluorouracil in nuclear and cellular morphology, proliferation, cell cycle, apoptosis, cytoskeletal and caveolar distribution in primary cultures of smooth muscle cells

Colon cancer is one of the most prevalent types of cancer in the world and is one of the leading causes of cancer death. The anti-metabolite 5- fluorouracil (5-FU) is widely used in the treatment of patients with colon cancer and other cancer types. 5-FU-based chemotherapy has been shown to be very efficient in the improvement of overall survival of the patients and for the eradication of the disease. Unfortunately, common side effects of 5-FU include severe alterations in the motility of the gastrointestinal tissues. Nevertheless, the molecular and cellular effects of 5-FU in smooth muscle cells are poorly understood. Primary smooth muscle cell cultures are an important tool for studies of the biological consequences of 5-FU at the cellular level. The avian gizzard is one of the most robust organs of smooth muscle cells. Here we studied the molecular and cellular effects of the chemotherapic drug 5-FU in a primary culture of chick gizzard smooth muscle cells. We found that treatment of smooth muscle cells with 5-FU inhibits cell proliferation by the arrest of cells in the G1 phase of cell cycle and induce apoptosis. 5-FU induced a decrease in the percentage of histone H3-positive cells. Treatment of cells with 5-FU induced changes in cellular and nuclear morphology, a decrease in the number of stress fibers and a major decrease in the number of caveolin-3 positive cells. Our results suggest that the disorganization of the actin cytoskeleton and the reduction of caveolin-3 expression could explain the alterations in contractility observed in patients treated with 5-FU. These findings might have an impact in the understanding of the cellular effects of 5-FU in smooth muscle tissues and might help the improvement of new therapeutic protocols for the treatment of colon cancer.

Effects of pegylated recombinant human megakaryocyte growth and development factor on 5-fluorouracil-induced thrombocytopenia in balloon-injured rats

We examined whether pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) affected 5-fluorouracil-induced thrombocytopenia without inducing more severe intimal thickening after injury to rat carotid arteries. Rat carotid arteries were injured using a balloon catheter on day 0. 5-Fluorouracil (100 mg kg(-1)) or vehicle was intravenously administered on day 1 in balloon-injured rats. PEG-rHuMGDF (100 microg kg(-1)) or vehicle was intravenously administered once a day on days 1-5 to balloon-injured rats given 5-fluorouracil or vehicle. 5-Fluorouracil (100 mg kg(-1), i.v.) caused a significant decrease in the platelet count from day 3 and peaked on days 7-9 in balloon-injured rats. PEG-rHuMGDF (100 microg kg(-1), i.v.) reduced this decrease on days 9 and 11. The administration of PEG-rHuMGDF did not accelerate the intimal thickening of balloon-injured arteries in rats treated with 5-fluorouracil compared with control balloon-injured rats. PEG-rHuMGDF did not increase plasma tumour growth factor-beta1 (TGF-beta1) from days 0-9 in balloon-injured rats compared with control balloon-injured rats. These results suggest that PEG-rHuMGDF ameliorated 5-fluorouracil-induced thrombocytopenia without accelerating the intimal thickening of balloon-injured arteries.

The effects of cyclophosphamide and its uroprotective agents, mesna and hyperbaric oxygen, on urinary bladder motility in guinea pigs

The aim of this research was to observe the effects of cyclophosphamide and its uroprotective agents, mesna and hyperbaric oxygen (HBO), on the motility of urinary bladder muscle in guinea pigs. In the experimental groups, mesna and cyclophosphamide were intraperitoneally injected at a dose of 21.5 mg/kg and 68.1 mg/kg, respectively. For the combination of mesna and cyclophosphamide, one dose of mesna was injected 20 min before cyclophosphamide administration and three additional injections of mesna were repeated every three hours. A total of 8 HBO exposures were performed at 2.8 ATA for 90 min twice daily for another experimental group. In the HBO and cyclophosphamide combined group 5 HBO exposures were given prophylactically before cyclophosphamide. The combination of mesna, HBO and cyclophosphamide was administered by the same procedure. The contractions obtained in response to acetylcholine (ACh, 10(-4) M) in the control group were reduced using cyclophosphamide and HBO individually, but not by mesna. However, the contractions belonging to the various combinations of these three agents were not different from those seen in the control group. On the other hand, the combinations of cyclophosphamide, mesna and HBO showed higher responses to ACh than the groups in which cyclophosphamide and HBO were used individually, while the responses elicited by the cyclophosphamide and HBO combination were greater than those seen in the group treated with HBO only.

Histopathologic study of stenotic and occluded transjugular intrahepatic portosystemic shunts

PURPOSE

A detailed histopathologic analysis of three stenotic and two occluded transjugular intrahepatic portosystemic shunts was performed to evaluate the nature and cause of each shunt abnormality.

PATIENTS AND METHODS

The study group consists of five patients who developed a shunt stenosis or occlusion and subsequently underwent liver transplantation or autopsy. Shunt specimens were examined grossly and microscopically.

RESULTS

The pseudointima was composed of granulation tissue, which was generally denser and more cellular near the luminal surface. Pseudointima was thicker in the parenchymal portion of the shunt than at the venous ends. A contiguous single layer of endothelial-like cells lined the majority of the luminal surface of each shunt. Scattered debris and clot covered 10%-15% of the luminal surfaces. Transected bile ducts were noted in three cases. Bile staining was detected around the transected ducts, and bile pigment was incorporated into the developing pseudointima.

CONCLUSIONS

Pseudointimal hyperplasia appears to be the causative lesion in these obstructions. An inflammatory reaction incited by bile extravasation may have contributed to pseudointimal proliferation in three cases.

Percutaneous femoropopliteal graft placement

PURPOSE

Femoropopliteal bypass surgery is now recommended for the treatment of long-segment or diffuse superficial femoral artery disease. The authors describe a technique for percutaneous placement of a prosthetic femoropopliteal graft.

PATIENTS AND METHODS

The technique has been accomplished with conventional polytetrafluoroethylene graft material and a variety of implantation techniques in eight patients.

RESULTS

Technical success was achieved in all patients who underwent graft placement. Grafts up to 28 cm in length were placed, and graft patency was demonstrated up to 10 months after implantation. Six of the eight patients were asymptomatic during the follow-up period; one patient who had symptoms during this time underwent thrombolysis and redilation of the distal stent, and the symptoms resolved. In the other patient with symptoms, the procedure failed clinically because of poor runoff.

CONCLUSION

This study demonstrates the feasibility of percutaneous graft placement in the femoral artery, but durability must be established in relation to traditional bypass surgery before it can be recommended on a wider scale.