Pllans-II: Unveiling the Action Mechanism of a Promising Chemotherapeutic Agent Targeting Cervical Cancer Cell Adhesion and Survival Pathways.

Despite advances in chemotherapeutic drugs used against cervical cancer, available chemotherapy treatments adversely affect the patient's quality of life. For this reason, new molecules from natural sources with antitumor potential and few side effects are required. In previous research, Pllans-II, a phospholipase A2 type-Asp49 from Porthidium lansbergii lansbergii snake venom, has shown selective attack against the HeLa and Ca Ski cervical cancer cell lines. This work suggests that the cytotoxic effect generated by Pllans-II on HeLa cells is triggered without affecting the integrity of the cytoplasmic membrane or depolarizing the mitochondrial membranes. The results allow us to establish that cell death in HeLa is related to the junction blockage between α5ß1 integrins and fibronectin of the extracellular matrix. Pllans-II reduces the cells' ability of adhesion and affects survival and proliferation pathways mediated by intracellular communication with the external environment. Our findings confirmed Pllans-II as a potential prototype for developing a selective chemotherapeutic drug against cervical cancer.

Pllans-II Induces Cell Death in Cervical Cancer Squamous Epithelial Cells via Unfolded Protein Accumulation and Endoplasmic Reticulum Stress.

Due to the lack of chemotherapeutic drugs that selectively affect cervical cancer cells, natural sources such as snake venom are currently being investigated for molecules with antitumor potential. Pllans-II, a phospholipase A2 type-Asp49 from Porthidium lansbergii lansbergii snake venom, induced cell death in a cervical cancer cell line-Ca Ski-related to dysfunction in the ability to resolve endoplasmic reticulum stress, evidenced by sub-expression of genes such as PERK, ERO1 PDIs, HSP70, and CHOP. Western blot analysis validated the last two genes' sub-expression at the protein level. In addition, Pllans-II presented a dose-dependent cytotoxic effect on cancer cells and an insignificant effect on healthy endothelial cells (HUVEC). Additionally, Pllans-II inhibited cancer cells' adhesion and migration capacity, induced cell cycle arrest in the G2/M phase, and induced apoptosis stimulated possibly by the extrinsic route. These results demonstrate for the first time that Pllans-II has an antitumor effect on a squamous epithelial cervical cancer cell line and represents a possible biotechnological tool for designing a prominent antitumor agent.

Evaluation of the systemic alterations triggers by Porthidium lansbergii lansbergii snake venom.

The systemic effects generated by Porthidium lansbergii lansbergii envenoming, a species found in the northern region of Colombia, is poorly known. The present study aimed to analyze for the first time the mice's behavior, the histological alterations, and changes in biochemical markers levels resulting from the intraperitoneal injection of an LD50 of P. lansbergii lansbergii snake venom on mice. The envenoming mice displayed hypodynamic condition, clonic head movements, accompanied by bradypnea and thoracoabdominal imbalance. After 7 h of envenoming, the mice showed an ecchymotic region at the injection site, including bleeding in the pleural, liver, and kidney capsules. The effect on the brain revealed a micro-hemorrhage in the sensorimotor cortex with substantial loss of neurons. The venom caused dilated blood vessels in lung tissue, with endothelial necrosis associated with alveolar rupture. The liver showed parenchyma alteration with many extravasated erythrocytes. The kidneys exhibited renal tubules necrosis and a statistically significant increase in creatinine concentration. ALP and ALT's enzymatic activities remained constant at 7 h after envenoming but increased at 12 h. AST and LDH were significantly increased at 7 h but decreased to the near baseline 12 h after venom administration. Massive hemorrhages could trigger a hypovolemic shock, which could lead to death after several h without treatment. Knowledge of P. lansbergii lansbergii snake bites' injuries is essential to make the appropriate diagnostic in human envenoming cases by this snake.

Antitumoral Potential of Lansbermin-I, a Novel Disintegrin from Porthidium lansbergii lansbergii Venom on Breast Cancer Cells.

BACKGROUND: Disintegrins from snake venoms bind with high specificity cell surface integrins, which are important pharmacological targets associated with cancer development and progression. OBJECTIVE: In this study, we isolated a disintegrin from the Porthidium lansbergii lansbergii venom and evaluated its antitumoral effects on breast cancer cells. METHODS: The isolation of the disintegrin was performed on RP-HPLC and the inhibition of platelet aggregation was evaluated on human platelet-rich plasma. The inhibition of cell adhesion was also evaluated in vitro on cultures of cell lines by the MTT method as well as the inhibition of breast cancer cell migration by the wound healing assay. The binding of the disintegrin to integrin subunits was verified by flow cytometry and confocal microscopy. Finally, inhibition of angiogenesis was assessed in vitro on HUVEC cells and the concentration of VEGF was measured in the cellular supernatants. RESULTS: The disintegrin, named Lansbermin-I, is a low molecular weight protein (< 10 kDa) that includes an RGD on its sequence identified previously. Lansbermin-I showed potent inhibition of ADP and collagen-induced platelet aggregation on human plasma and also displayed inhibitory effects on the adhesion and migration of breast cancer MCF7 and MDA-MB 231cell lines, without affecting nontumorigenic breast MCF-10A and lung BEAS cells. Additionally, Lansbermin-I prevented MCF7 cells to adhere to fibronectin and collagen, and also inhibited in vitro angiogenesis on human endothelial HUVEC cells. CONCLUSION: Our results display the first report on the antitumor and anti-metastatic effects of an RGDdisintegrin isolated from a Porthidium snake venom by possibly interfering with α2 and/or ß1-containing integrins. Thus, Lansbermin-I could be an attractive model to elucidate the role of disintegrins against breast cancer development.

Phylogeny and toxicological assessments of two Porthidium lansbergii lansbergii morphotypes from the caribbean region of Colombia.

After a snakebite accident, species identification is of vital importance. However, the existence of intraspecific differences in the body coloration patterns of venomous snakes can generate confusion and delay a convenient and effective treatment. This is the situation for Porthidium lansbergii lansbergii from Colombia, for which two distinctive color morphs occur, and the relationship of these morphs with venom toxicity is unknown. Therefore, venom samples from specimens of these two morphs were collected from the Colombian Caribbean region, and their protein profiles compared. Likewise, their venom functional activities were evaluated in vitro and in vivo in BALB/C mice. Additionally, using sequences of the mitochondrial cytochrome b (Cyt-b) gene, the relationship between these Colombian P. lansbergii lansbergii morphotypes was investigated, and their phylogenetic positions were determined for the first time using Bayesian inference. Despite the noticeable coloration divergence between the individuals analyzed, similar protein profiles of their venoms were observed. Additionally, neither their lethality nor biochemical activities were notably different. In general, both venoms were highly proteolytic, lacked a coagulant effect in vitro, and extended the clotting time due to the action of venom components, such as disintegrins and proteases, that induce defibrination. These results agreed with the result of our phylogenetic analysis, suggesting that the two chromatic morphs do not represent isolated populations. The phylogenetic analyses also supported the currently recognized P. lansbergii lansbergii subspecies as a monophyletic complex. In conclusion, the results of this investigation suggest similar clinical manifestations regardless of body coloration after a P. lansbergii lansbergii envenomation, and pools can therefore be used for antivenom development, medical treatments, and further research efforts.

Divergent functional profiles of acidic and basic phospholipases A2 in the venom of the snake Porthidium lansbergii lansbergii.

The Lansberg's hognose pitviper, Porthidium lansbergii lansbergii, inhabits northern Colombia. A recent proteomic characterization of its venom (J. Proteomics [2015] 114, 287-299) revealed the presence of phospholipases A2 (PLA2) accounting for 16.2% of its proteins. The two most abundant PLA2s were biochemically and functionally characterized. Pllans-I is a basic, dimeric enzyme with a monomer mass of 14,136 Da, while Pllans-II is an acidic, monomeric enzyme of 13,901 Da. Both have Asp49 in their partial amino acid sequences and, accordingly, are catalytically active upon natural or synthetic substrates. Nevertheless, these two enzymes differ markedly in their bioactivities. Pllans-I induces myonecrosis, edema, and is lethal by intracerebro-ventricular injection in mice, as well as cytolytic and anticoagulant in vitro. In contrast, Pllans-II is devoid of these effects, except for the induction of a moderate edema. In spite of lacking myotoxicity, Pllans-II enhances the muscle damaging action of Pllans-I in vivo. Altogether, results further illustrate the divergent functional profiles of basic and acidic PLA2s in viperid venoms, and suggest that Pllans-I plays a myotoxic role in envenomings by P. l. lansbergii, whereas Pllans-II, apparently devoid of toxicity, enhances muscle damage caused by Pllans-I.

Proteomic and functional analyses of the venom of Porthidium lansbergii lansbergii (Lansberg's hognose viper) from the Atlantic Department of Colombia.

The venom of the Lansberg's hognose pitviper, Porthidium lansbergii lansbergii, a species found in the northern region of Colombia, is poorly known. Aiming to increase knowledge on Porthidium species venoms, its proteomic analysis and functional evaluation of in vitro and in vivo activities relevant to its toxicity were undertaken. Out of 51 protein components resolved by a combination of RP-HPLC and SDS-PAGE, 47 were assigned to 12 known protein families. In similarity with two previously characterized venoms from species within this genus, Porthidium nasutum and Porthidium ophryomegas, that of P. lansbergii lansbergii was dominated by metalloproteinases, although in lower proportion. A common feature of the three Porthidium venoms appears to be a high content of disintegrins. Proteins not previously observed in Porthidium venoms belong to the vascular endothelium growth factor, phosphodiesterase, and phospholipase B families. P. lansbergii lansbergii venom showed relatively weak lethal activity to mice, and induced a moderate local myotoxicity, but considerable hemorrhage. Its isolated VEGF component showed potent edema-inducing activity in the mouse footpad assay. Significant thrombocytopenia, but no other major hematological changes, were observed in envenomed mice. In vitro, this venom lacked coagulant effect on human plasma, and induced a potent inhibition of platelet aggregation which was reproduced by its purified disintegrin components. Phospholipase A2 and proteolytic activities were also demonstrated. Overall, the compositional and functional data herein described for the venom of P. lansbergii lansbergii may contribute to a better understanding of envenomings by this pitviper species, for which specific clinical information is lacking. BIOLOGICAL SIGNIFICANCE: Porthidium lansbergii lansbergii is estimated to be responsible for nearly 20% of snakebite envenoming cases at the Atlantic Department of Colombia, but the identity and functional properties of its venom components are largely unknown. This study provides the first combined proteomic and functional analyses of the venom of this pitviper, which may contribute to a better understanding of the features of envenomings by this species.