Biomolecules 2019, 9, 92; doi:10.3390/biom9030092 www.mdpi.com/journal/biomolecules Article [Pt(O,O′-acac)(γ-acac)(DMS)] Induces Autophagy in Caki-1 Renal Cancer Cells Giovanna Antonaci 1 , Luca Giulio Cossa 1 , Antonella Muscella 2, *, Carla Vetrugno 2 , Sandra Angelica De Pascali 3 , Francesco Paolo Fanizzi 3, * and Santo Marsigliante 1 1 Laboratory of Cell Physiology, Department of Biological and Environmental Sciences and Technologies (Di.S.Te.B.A.), University of Salento, 73100 Lecce, Italy; giovanna.antonaci@unisalento.it (G.A.); lucagiulio.cossa@gmail.com (L.G.C.); santo.marsigliante@unisalento.it (S.M.) 2 Laboratory of Cell Pathology, Department of Biological and Environmental Sciences and Technologies (Di.S.Te.B.A.), University of Salento, 73100 Lecce, Italy; carlottavetrugno@virgilio.it 3 Laboratory of General Inorganic Chemistry, Department of Biological and Environmental Sciences and Technologies (Di.S.Te.B.A.), University of Salento, 73100 Lecce, Italy; sandra.depascali@unisalento.it * Correspondence: antonella.muscella@unisalento.it (A.M.); fp.fanizzi@unisalento.it (F.P.F.) Received: 24 January 2019; Accepted: 26 February 2019; Published: 6 March 2019 Abstract: We have demonstrated the cytotoxic effects of [Pt(O,O′-acac)(γ-acac)(dimethyl sulfide (DMS))] on various immortalized cell lines, in primary cultures, and in murine xenograft models in vivo. Recently, we also showed that [Pt(O,O’-acac)(γ-acac)(DMS)] is able to kill Caki-1 renal cells both in vivo and in vitro. In the present paper, apoptotic and autophagic effects of [Pt(O,O′-acac)(γ- acac)(DMS)] and cisplatin were studied and compared using Caki-1 cancerous renal cells. The effects of cisplatin include activation of caspases, proteolysis of enzyme poly ADP ribose polymerase (PARP), control of apoptosis modulators B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and BH3-interacting domain death agonist (Bid), and cell cycle arrest in G2/M phase. Conversely, [Pt(O,O’-acac)(γ-acac)(DMS)] did not induce caspase activation, nor chromatin condensation or DNA fragmentation. The effects of [Pt(O,O’-acac)(γ-acac)(DMS)] include microtubule-associated proteins 1A/1B light chain 3B (LC3)-I to LC3-II conversion, Beclin-1 and Atg- 3, -4, and -5 increase, Bcl-2 decrease, and monodansylcadaverine accumulation in autophagic vacuoles. [Pt(O,O’-acac)(γ-acac)(DMS)] also modulated various kinases involved in intracellular transduction regulating cell fate. [Pt(O,O’-acac)(γ-acac)(DMS)] inhibited the phosphorylation of mammalian target of rapmycin (mTOR), p70S6K, and AKT, and increased the phosphorylation of c-Jun N-terminal kinase (JNK1/2), a kinase activity pattern consistent with autophagy induction. In conclusion, while in past reports the high cytotoxicity of [Pt(O,O’-acac)(γ-acac)(DMS)] was always attributed to its ability to trigger an apoptotic process, in this paper we show that Caki-1 cells die as a result of the induction of a strong autophagic process. Keywords: autophagy; cancerous renal cells; apoptosis; cisplatin 1. Introduction Renal cell carcinoma (RCC) is among the top 10 most common cancers in the world; about 20%– 30% of patients with RCC have metastasis to the first diagnosis, and over 95% of patients have multiple metastases [1]. Renal cell carcinoma resistance to conventional medical therapy remains the main obstacle to survival, and it is therefore important to develop new therapeutic strategies [2,3]. Indeed, many chemotherapeutic agents have been experienced in the treatment of RCC; among them, the cisplatin-based drugs are among the most common and effective chemotherapeutic agents for