Cell proliferation in a malignant angioendothelioma during sequential chemotherapy

Obtaining New Candidate Peptides for Biological Anticancer Drugs from Enzymatic Hydrolysis of Human and Bovine Hemoglobin

Enzymatic hydrolysis of bovine and human hemoglobin generates a diversity of bioactive peptides, mainly recognized for their antimicrobial properties. However, antimicrobial peptides stand out for their ability to specifically target cancer cells while preserving rapidly proliferating healthy cells. This study focuses on the production of bioactive peptides from hemoglobin and evaluates their anticancer potential using two distinct approaches. The first approach is based on the use of a rapid screening method aimed at blocking host cell protein synthesis to evaluate candidate anticancer peptides, using Lepidium sativum seed germination as an indicator. The results show that: (1) The degree of hydrolysis (DH) significantly influences the production of bioactive peptides. DH levels of 3 to 10% produce a considerably stronger inhibition of radicle growth than DH 0 (the native form of hemoglobin), with an intensity three to four times greater. (2) Certain peptide fractions of bovine hemoglobin have a higher activity than those of human hemoglobin. (3) The structural characteristics of peptides (random coil or alpha helix) play a crucial role in the biological effects observed. (4) The α137-141 peptide, the target of the study, was the most active of the fractions obtained from bovine hemoglobin (IC50 = 29 ± 1 µg/mL) and human hemoglobin (IC50 = 48 ± 2 µg/mL), proving to be 10 to 15 times more potent than the other hemoglobin fractions, attributed to its strong antimicrobial potential. The second approach to assessing anticancer activity is based on the preliminary in vitro analysis of hydrolysates and their peptide fractions, with a focus on the eL42 protein. This protein is of major interest due to its overexpression in all cancer cells, making it an attractive potential target for the development of anticancer molecules. With this in mind, astudy was undertaken using a method for labeling formylase (formyl-methionyl-tRNA transformylase (FMTS)) with oxidized tRNA. This approach was chosen because of the similarities in the interaction between formylase and the eL42 protein with oxidized tRNA. The results obtained not only confirmed the previous conclusions but also reinforced the hypothesis that the inhibition of protein synthesis plays a key role in the anticancer mechanism of these peptides. Indeed, the data suggest that samples containing α137-141 peptide (NKT) and total hydrolysates may have modulatory effects on the interaction between FMTS and oxidized tRNA. This observation highlights the possibility that the latter could influence molecular binding mechanisms, potentially resulting in a competitive situation where the ability of substrate tRNA to bind efficiently to ribosomal protein is compromised in their presence. Ultimately, these results suggest the feasibility of obtaining candidate peptides for biological anticancer drugs from both human and bovine hemoglobin sources. These scientific advances show new hope in the fight against cancer, which affects a large number of people around the world.

Antimicrobial peptides with selective antitumor mechanisms: prospect for anticancer applications

In the last several decades, there have been significant advances in anticancer therapy. However, the development of resistance to cancer drugs and the lack of specificity related to actively dividing cells leading to toxic side effects have undermined these achievements. As a result, there is considerable interest in alternative drugs with novel antitumor mechanisms. In addition to the recent approach using immunotherapy, an effective but much cheaper therapeutic option of pharmaceutical drugs would still provide the best choice for cancer patients as the first line treatment. Ribosomally synthesized cationic antimicrobial peptides (AMPs) or host defense peptides (HDP) display broad-spectrum activity against bacteria based on electrostatic interactions with negatively charged lipids on the bacterial surface. Because of increased proportions of phosphatidylserine (negatively charged) on the surface of cancer cells compared to normal cells, cationic amphipathic peptides could be an effective source of anticancer agents that are both selective and refractory to current resistance mechanisms. We reviewed herein the prospect for AMP application to cancer treatment, with a focus on modes of action of cationic AMPs.

Cutaneous angiosarcoma complicating morbid obesity

Herein, we report a case of cutaneous angiosarcoma in a 35-year-old, morbidly obese woman. The tumor arose in the most dependent portion of the lower abdominal panniculus and showed typical changes of chronic lymphedema. The patient underwent a radical resection of her lower abdominal wall panniculus, which showed a multicentric, high-grade angiosarcoma with bilateral superficial inguinal lymph node metastases. Histologically, conventional vasoformative areas were admixed with poorly differentiated sheets of spindle and epithelioid cells. Factor VIII was focally positive (membranous), whereas CD31 showed robust, diffuse positivity (membranous and cytoplasmic). The initial margins of resection were negative, and no follow-up radiation or chemotherapy was given. Following a recurrence at the previous excision site, the patient died 7 months after the surgery. Postmortem examination revealed a widely metastatic tumor that involved multiple organ systems. We believe this is the second report of cutaneous angiosarcoma occurring in a chronically lymphedematous abdominal panniculus due to morbid obesity.

Angiosarcoma of the face and scalp

Angiosarcoma of the face and scalp developed in 12 patients. The patients were five women and seven men with an average age of 71 years. Initial features were solitary or multiple violaceous vascular nodules or plaques. The clinical course was complicated by ulceration, secondary infection, bleeding, anemia, infiltration into the underlying bones, tumor cachexia, and death. Metastases were not observed. Histologically, seemingly benign hemangiomatous capillary-like structures were found in some areas of the tumors, with richly cellular, solid sarcomatous proliferations in other areas. Early and extensive surgical excision is the therapy of choice, but generally it does not alter the relentless course of the disease. Neither palliative radiation therapy nor polychemotherapy is capable of interfering with tumor progression.

Cutaneous pathobiology mediated by chemotherapy

A histopathologic study of side effects of chemotherapy on normal skin was made by light microscopy and radioautography after incorporation of tritiated thymidine. Two psoriatic patients were studied after methotrexate treatment and one after polychemotherapy for an osteosarcoma 2--5 days after administration of methotrexate. Four biological effects can occur: cellular death, recruitment of cells from a resting phase into the cell cycle of proliferation, synchronization of cells in that cycle and blockage of cells in specific phases. Sub-lethal signs and necrosis were recognized in the epidermis as vacuolar alterations, cytoplasmic inclusions, swelling of keratinocytes, apoptosis and dyskeratosis. Bullae resulted from epidermal necrolysis. The labelling index of normal looking keratinocytes was very high. Within capillaries, plump and hyperchromatic endothelial cells were increased in number, as was their labelling index. Fibroblasts and cells of the eccrine glands were also labelled in number. The number of labelled nuclei within these cell lines reflects the recruitment and synchronization in the cell cycle and the blockage in S phase.