MTH1 inhibition synergizes with ROS-inducing agents to trigger cervical cancer cells undergoing parthanatos.

Cervical cancer cells possess high levels of reactive oxygen species (ROS); thus, increasing oxidative stress above the toxicity threshold to induce cell death is a promising chemotherapeutic strategy. However, the underlying mechanisms of cell death are elusive, and efficacy and toxicity issues remain. Within DNA, 8-oxo-7,8-dihydroguanine (8-oxoG) is the most frequent base lesion repaired by 8-oxoguanine glycosylase 1 (OGG1)-initiated base excision repair. Cancer cells also express high levels of MutT homolog 1 (MTH1), which prevents DNA replication-induced incorporation of 8-oxoG into the genome by hydrolyzing 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate (8-oxo-dGTP). Here, we revealed that ROS-inducing agents triggered cervical cancer to undergo parthanatos, which was mainly induced by massive DNA strand breaks resulting from overwhelming 8-oxoG excision by OGG1. Furthermore, the MTH1 inhibitor synergized with a relatively low dose of ROS-inducing agents by enhancing 8-oxoG loading in the DNA. In vivo, this drug combination suppressed the growth of tumor xenografts, and this inhibitory effect was significantly decreased in the absence of OGG1. Hence, the present study highlights the roles of base repair enzymes in cell death induction and suggests that the combination of lower doses of ROS-inducing agents with MTH1 inhibitors may be a more selective and safer strategy for cervical cancer chemotherapy.

Stereoselective Iron-Catalyzed Alkylation of Enamides with Cyclopropanols via Oxidative C(sp2)-H Functionalization.

Established herein is a radical-mediated C-H alkylation of enamides with cyclopropanols. An environmentally benign catalytic system with iron salt and air is used to permit the oxidative coupling process. The protocol demonstrates a broad substrate scope, allowing the stereoselective synthesis of alkylated enamides. The value of this strategy is further reflected by late-stage diversification of complex cyclopropanol-containing molecules and downstream transformations. Mechanistic studies reveal the dual role of iron salt in the reaction.

Celastrol Targets Cullin-Associated and Neddylation-Dissociated 1 to Prevent Fibroblast-Myofibroblast Transformation against Pulmonary Fibrosis.

Celastrol (CEL), a pentacyclic triterpene compound, has been proven to have a definite antipulmonary fibrosis effect. However, its direct targets for antipulmonary fibrosis remain unknown. In this study, we designed and synthesized a series of celastrol-based probes to identify the direct targets in human pulmonary fibroblasts using an activity-based protein profiling strategy. Among many fished targets, we identified a key protein, cullin-associated and neddylation-dissociated 1 (CAND1), which was involved in fibroblast-myofibroblast transformation (FMT). More importantly, we found that the inhibitory effect of celastrol on FMT is dependent on CAND1, through improving the interactions between CAND1 and Cullin1 to promote the activity of Skp1/Cullin1/F-box ubiquitin ligases. In silico studies and cysteine mutation experiments further demonstrated that Cys264 of CAND1 is the site for conjugation of celastrol. This reveals a new mechanism of celastrol against pulmonary fibrosis and may provide a novel therapeutic option for antipulmonary fibrosis.

Linking oxidative DNA lesion 8-OxoG to tumor development and progression.

Cells of the aerobic metabolic organism are inevitably subjected to the damage from reactive oxygen species (ROS). ROS cause multiple forms of DNA damage, among which the oxidation product of guanine G 8-hydroxyguanine (8-oxoG) is the most frequent DNA oxidative damage, recognized by the specific glycosidase OGG1 that initiates the base excision repair pathway. If left unrepaired, 8-oxoG may pair with A instead of C, leading to a mutation of G: C to T: A during replication. Thus, the accumulation of 8-oxoG or the abnormal OGG1 repair is thought to affect gene function, which in turn leads to the development of tumor or aging-related diseases. However, a series of recent studies have shown that 8-oxoG tends to be produced in regulatory regions of the genome. 8-oxoG can be regarded as an epigenetic modification, while OGG1 is a specific reader of this information. Substrate recognition, binding or resection by OGG1 can cause DNA conformation changes or affect histone modifications, causing up-regulation or down-regulation of genes with different properties. Thus, in addition to the potential genotoxicity, the association of guanine oxidative damage with development of tumors is closely related to its aberrant initiation of gene expression through epigenetic mechanisms. In this review, we summarize the underlying mechanism of 8-oxoG and repair enzyme OGG1 in tumor development and progression, with aims to interpret the relationship between DNA oxidative damage and tumor from a new perspective, and provide new ideas and targets for tumor treatment.

Coronaviruses Nsp5 Antagonizes Porcine Gasdermin D-Mediated Pyroptosis by Cleaving Pore-Forming p30 Fragment.

Coronaviruses (CoVs) are a family of RNA viruses that typically cause respiratory, enteric, and hepatic diseases in animals and humans. Here, we use porcine epidemic diarrhea virus (PEDV) as a model of CoVs to illustrate the reciprocal regulation between CoV infection and pyroptosis. For the first time, we elucidate the molecular mechanism of porcine gasdermin D (pGSDMD)-mediated pyroptosis and demonstrate that amino acids R238, T239, and F240 within pGSDMD-p30 are critical for pyroptosis. Furthermore, 3C-like protease Nsp5 from SARS-CoV-2, MERS-CoV, PDCoV, and PEDV can cleave pGSDMD at the Q193-G194 junction to produce two fragments unable to trigger pyroptosis. The two cleaved fragments could not inhibit PEDV replication. In addition, Nsp5 from SARS-CoV-2 and MERS-CoV also cleave human GSDMD (hGSDMD). Therefore, we provide clear evidence that PEDV may utilize the Nsp5-GSDMD pathway to inhibit pyroptosis and, thus, facilitate viral replication during the initial period, suggesting an important strategy for the coronaviruses to sustain their infection. IMPORTANCE Recently, GSDMD has been reported as a key executioner for pyroptosis. This study first demonstrates the molecular mechanism of pGSDMD-mediated pyroptosis and that the pGSDMD-mediated pyroptosis protects host cells against PEDV infection. Notably, PEDV employs its Nsp5 to directly cleave pGSDMD in favor of its replication. We found that Nsp5 proteins from other coronaviruses, such as porcine deltacoronavirus, severe acute respiratory syndrome coronavirus 2, and Middle East respiratory syndrome coronavirus, also had the protease activity to cleave human and porcine GSDMD. Thus, we provide clear evidence that the coronaviruses might utilize Nsp5 to inhibit the host pyroptotic cell death and facilitate their replication during the initial period, an important strategy for their sustaining infection. We suppose that GSDMD is an appealing target for the design of anticoronavirus therapies.

Variations in phenolic acids and antioxidant activity of navel orange at different growth stages.

Ripe navel orange has abundant amounts of phenolic compounds. Few studies monitored changes in these compounds during ripening. In this study, the effects of navel orange maturation on dynamic changes in antioxidant activity, total phenolic content (TPC), total flavonoid content (TFC) and phenolic acids were investigated. Five growth stages of navel orange were studied, and nine phenolic acids were detected via high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-QQQ-MS). Results showed that antioxidant activity, TFC and TPC decreased gradually with fruit ripening. The concentrations of most phenolic acids also declined during fruit maturation, except for free fractions of sinapic acid and bound fractions of ferulic and caffeic acids. Ferulic acid was the most dominant of all phenolic acids at all growth stages. Partial least-squares showed significant differences among fruits of different maturities. A significant correlation between antioxidant capacity, TPC, TFC and some phenolic acids was found.

A well-differentiated liposarcoma of the prevertebral space: a case report.

Liposarcoma is common in adults; however, it very rarely occurs in the retropharyngeal space, and to date, no cases of liposarcoma in the prevertebral space have been reported. A 78-year-old man presented at the Otolaryngology Department with a 1-month history of dyspnea and dysphonia. Magnetic resonance imaging of the neck reveled a retropharyngeal mass extending from the superior margin of the axis to the level of the 7th cervical vertebra. A computed tomography scan of the patient's neck uncovered the relationship between the mass and its' surrounding structures. Based on the above examinations, a diagnosis of retropharyngeal liposarcoma was made initially. The patient underwent transoral surgical excision with the assistance of a nasal endoscope. During surgery, the tumor was located in the prevertebral space. Combined with pathology and immunohistochemistry examinations, the diagnosis was modified to well-differentiated liposarcoma of the prevertebral space. At the 1-year follow-up, the patient was well and there was no evidence of recurrence. The long-term outcomes are not yet known. Liposarcoma of the prevertebral space may sometimes be misdiagnosed as retropharyngeal liposarcoma; however, in our view, it is not necessary to focus on differentiating between enormous retropharyngeal and prevertebral tumors. In relation to the short-term outcome, complete excision using the transoral approach with the aid of nasal endoscope may present a better choice than the cervical approach in treating these tumors, especially in old people.

Clinical practice guidelines for the diagnosis and treatment of adult diffuse glioma-related epilepsy.

BACKGROUND: Glioma-related epilepsy (GRE) is defined as symptomatic epileptic seizures secondary to gliomas, it brings both heavy financial and psychosocial burdens to patients with diffuse glioma and significantly decreases their quality of life. To date, there have been no clinical guidelines that provide recommendations for the optimal diagnostic and therapeutic procedures for GRE patients. METHODS: In March 2017, the Joint Task Force for GRE of China Association Against Epilepsy and Society for Neuro-Oncology of China launched the guideline committee for the diagnosis and treatment of GRE. The guideline committee conducted a comprehensive review of relevant domestic and international literatures that were evaluated and graded based on the Oxford Centre for Evidence-Based Medicine Levels of Evidence, and then held three consensus meetings to discuss relevant recommendations. The recommendations were eventually given according to those relevant literatures, together with the experiences in the diagnosis and treatment of over 3000 GRE cases from 24 tertiary level hospitals that specialize in clinical research of epilepsy, glioma, and GRE in China. RESULTS: The manuscript presented the current standard recommendations for the diagnostic and therapeutic procedures of GRE. CONCLUSIONS: The current work will provide a framework and assurance for the diagnosis and treatment strategy of GRE to reduce complications and costs caused by unnecessary treatment. Additionally, it can serve as a reference for all professionals involved in the management of patients with GRE.

Multiprotein Dynamic Combinatorial Chemistry: A Strategy for the Simultaneous Discovery of Subfamily-Selective Inhibitors for Nucleic Acid Demethylases FTO and ALKBH3.

Dynamic combinatorial chemistry (DCC) is a powerful supramolecular approach for discovering ligands for biomolecules. To date, most, if not all, biologically templated DCC systems employ only a single biomolecule to direct the self-assembly process. To expand the scope of DCC, herein, a novel multiprotein DCC strategy has been developed that combines the discriminatory power of a zwitterionic "thermal tag" with the sensitivity of differential scanning fluorimetry. This strategy is highly sensitive and could differentiate the binding of ligands to structurally similar subfamily members. Through this strategy, it was possible to simultaneously identify subfamily-selective probes against two clinically important epigenetic enzymes: FTO (7; IC50 =2.6 µm) and ALKBH3 (8; IC50 =3.7 µm). To date, this is the first report of a subfamily-selective ALKBH3 inhibitor. The developed strategy could, in principle, be adapted to a broad range of proteins; thus it is of broad scientific interest.

Effects of Anterior Capsulotomy on Decision Making in Patients with Refractory Obsessive-Compulsive Disorder.

Despite various lines of evidence implicating impaired decision-making ability in individuals with obsessive-compulsive disorder (OCD), neuropsychological investigation has generated inconsistent findings. Although the cortico-striato-thalamo-cortical (CSTC) circuitry has been suggested, the involvement of the cortex has not yet been fully demonstrated. Moreover, it is unknown whether surgical intervention on the CSTC circuitry results in a predicted improvement of decision-making ability of OCD. Here we present a study of decision making based on the Iowa Gambling Task (IGT) to investigate decision making in a large sample of individuals with treatment-resistant OCD with and without anterior capsulotomy (AC). Task performance was evaluated in healthy subjects, individuals with OCD that had not undergone surgery, and postsurgical OCD patients with AC. The latter group was further divided into a short-term postsurgical group and a long-term postsurgical group. We found that the OCD patients without surgery performed significantly worse than the healthy controls on the IGT. There were no significant differences in decision-making between the presurgical OCD patients and those at the short-term postsurgical follow-up. Decision-making ability of the long-term postsurgical OCD patients was improved to the level comparable to that of healthy controls. All clinical symptoms (OCD, depression, and anxiety) assessed by psychiatric rating scales were significantly alleviated post-surgically, but exhibited no correlation with their IGT task performance. Our findings provide strong evidence that OCD is linked to impairments in decision-making ability; that impaired CSTC circuitry function is directly involved in the manifestation of OCD; and that AC related improvements in cognitive functions are caused by long-term plasticity in the brain circuitry.

Mitochondrial-Targeting MET Kinase Inhibitor Kills Erlotinib-Resistant Lung Cancer Cells.

Lung cancer cells harboring activating EGFR mutations acquire resistance to EGFR tyrosine kinase inhibitors (TKIs) by activating several bypass mechanisms, including MET amplification and overexpression. We show that a significant proportion of activated MET protein in EGFR TKI-resistant HCC827 lung cancer cells resides within the mitochondria. Targeting the total complement of MET in the plasma membrane and mitochondria should render these cells more susceptible to cell death and hence provide a means of circumventing drug resistance. Herein, the mitochondrial targeting triphenylphosphonium (TPP) moiety was introduced to the selective MET kinase inhibitor PHA665752. The resulting TPP analogue rapidly localized to the mitochondria of MET-overexpressing erlotinib-resistant HCC827 cells, partially suppressed the phosphorylation (Y1234/Y1235) of MET in the mitochondrial inner membrane and was as cytotoxic and apoptogenic as the parent compound. These findings provide support for the targeting of mitochondrial MET with a TPP-TKI conjugate as a means of restoring responsiveness to chemotherapy.

Three-Way Laryngeal Mask Reduces Anesthesia-Related Stress Responses in Bronchoalveolar Lavage: An Experimental Canine Study.

OBJECTIVE: To compare the ventilatory effects of the three-way laryngeal mask airway (TLMA) and tracheal tube (TT) on hemodynamics, respiratory function, and stress responses in a canine model during bronchoalveolar lavage (BAL). STUDY DESIGN: Experimental study. PLACE AND DURATION OF STUDY: The 303rd Hospital of the Chinese People's Liberation Army in May 2013. METHODOLOGY: Sixteen dogs were divided into two groups. MAP, SpO2 and HR were recorded before anesthesia (T0), immediately before intubation (T1), during intubation (T2), at 3 (T3) and 10 (T4) minutes after mechanical ventilation, at 10 (T5), 20 (T6), and 30 (T7) minutes during the course of BAL, during extubation (T8), and 3 minutes after extubation (T9). Tidal volume, peak inspiratory airway pressure, and expiratory CO2 pressure were recorded at time points T2, T5, T6, T7, and T8. Stress responses variables, including epinephrine and norepinephrine levels, were examined at time points T0, T2, T3, T5, T8, and T9. RESULTS: BAL was successfully completed in all animals. In comparison to the TT, the TLMA was capable of maintaining hemodynamic stability and ventilation (p < 0.05), and producing less stress responses (p < 0.05). CONCLUSION: In a canine model, ventilation with the TLMA was better than the TT during BAL in terms of maintaining effective ventilation and stable hemodynamics, and producing less stress responses.

"Turn-off" fluorescent data array sensor based on double quantum dots coupled with chemometrics for highly sensitive and selective detection of multicomponent pesticides.

As a popular detection model, the fluorescence "turn-off" sensor based on quantum dots (QDs) has already been successfully employed in the detections of many materials, especially in the researches on the interactions between pesticides. However, the previous studies are mainly focused on simple single track or the comparison based on similar concentration of drugs. In this work, a new detection method based on the fluorescence "turn-off" model with water-soluble ZnCdSe and CdSe QDs simultaneously as the fluorescent probes is established to detect various pesticides. The fluorescence of the two QDs can be quenched by different pesticides with varying degrees, which leads to the differences in positions and intensities of two peaks. By combining with chemometrics methods, all the pesticides can be qualitative and quantitative respectively even in real samples with the limit of detection was 2 × 10(-8) mol L(-1) and a recognition rate of 100%. This work is, to the best of our knowledge, the first report on the detection of pesticides based on the fluorescence quenching phenomenon of double quantum dots combined with chemometrics methods. What's more, the excellent selectivity of the system has been verified in different mediums such as mixed ion disruption, waste water, tea and water extraction liquid drugs.

Antiproliferative, DNA intercalation and redox cycling activities of dioxonaphtho[2,3-d]imidazolium analogs of YM155: A structure-activity relationship study.

The anticancer agent YM155 is widely investigated as a specific survivin suppressant. More recently, YM155 was found to induce DNA damage and this has raised doubts as to whether survivin is its primary target. In an effort to assess the contribution of DNA damage to the anticancer activity of YM155, several analogs were prepared and evaluated for antiproliferative activity on malignant cells, participation in DNA intercalation and free radical generation by redox cycling. The intact positively charged scaffold was found to be essential for antiproliferative activity and intercalation but was less critical for redox cycling where the minimal requirement was a pared down bicyclic quinone. Side chain requirements at the N(1) and N(3) positions of the scaffold were more alike for redox cycling and intercalation than antiproliferative activity, underscoring yet again, the limited structural overlaps for these activities. Furthermore, antiproliferative activities were poorly correlated to DNA intercalation and redox cycling. Potent antiproliferative activity (IC50 9-23 nM), exceeding that of YM155, was found for a minimally substituted methyl analog AB7. Like YM155 and other dioxonaphthoimidazoliums, AB7 was a modest DNA intercalator but with weak redox cycling activity. Thus, the capacity of this scaffold to inflict direct DNA damage leading to cell death may not be significant and YM155 should not be routinely classified as a DNA damaging agent.

"Turn-off-on" fluorescent sensor for (N-methyl-4-pyridyl) porphyrin -DNA and G-quadruplex interactions based on ZnCdSe quantum dots.

As a new detection model, the reversible fluorescence "turn-off-on" sensor based on quantum dots (QDs) has already been successfully employed in the detections of many biochemical materials, especially in the researches on the interactions between anticancer drugs. The previous studies, however, mainly focused on simple-structured oligonucleotides and Calf thymus DNA. G-quadruplex, an important target for anti-cancer drug with special secondary structure, has been stimulating increasing research interests. In this paper, we report a new detection method based on the fluorescence "turn-off-on" model with water-soluble ZnCdSe QDs as the fluorescent probe, to analyze the interactions between anticancer drug (N-methyl-4-pyridyl) porphyrin (TMPyP) and nucleic acid, especially the G-quadruplex. The fluorescence of QDs can be quenched by TMPyP via photo-induced electron transfer and fluorescence resonance energy transfer, while on the other hand, the combination between TMPyP and G-quadruplex releases QDs from their quenchers and thus recovers the fluorescence. Most importantly, the fluorescence "turn-off-on" model has been employed, for the first time, to analyze the impacts of special factors on the interaction between TMPyP and G-quadruplex. The excellent selectivity of the system has been verified in the studies of the interactions between TMPyP and different DNAs (double-stranded DNA, single-stranded G-quadruplex, and different types of G-quadruplexes) in Na(+) or K(+)-containing buffer.

N'-Alkylaminosulfonyl Analogues of 6-Fluorobenzylideneindolinones with Desirable Physicochemical Profiles and Potent Growth Inhibitory Activities on Hepatocellular Carcinoma.

The benzylideneindolinone 6-chloro-3-(3'-trifluoromethylbenzylidene)-1,3-dihydroindol-2-one (4) was reported to exhibit potent and selective growth inhibitory effects on hepatocellular carcinoma (HCC). Corroborative evidence supported multi-receptor tyrosine kinase (RTK) inhibition as a possible mode of action. However, the poor physicochemical properties of 4 limited its furtherance as a lead compound. In this study, the modification of 4 was investigated with the aim of improving its potency and physicochemical profile. The 6-fluorobenzylideneindolinone 3-12 bearing a 3'-N-propylaminosulfonyl substituent was found to be a promising substitute. Compound 3-12 [6-fluoro-3-(3'-N-propylaminosulfonylbenzylidene)-1,3-dihydroindol-2-one] was found to be tenfold more soluble than 4 and to have sub-micromolar growth inhibitory activities on HCC cells. It is apoptogenic and inhibits the phosphorylation of several RTKs in HuH7, of which the inhibition of FGFR4 and HER3 are prominent. Compound 3-12 decreased the tumor load in a physiologically relevant orthotopic HCC xenograft murine model. Structure-activity relationships support pivotal roles for the fluoro and N'-propylaminosulfonyl moieties in enhancing cell-based activity and moderating the physicochemical profile (solubility, permeability) of 3-12.

Identification of 3,5,6-substituted indolin-2-one's inhibitors of Aurora B by development of a luminescent kinase assay.

Aurora B kinase plays an important role in the cell normal mitosis and overexpresses in a variety of tumors. Inhibition of Aurora B kinase resulted in an apoptosis of cancer cells, which prevented tumor growth in xenograft models. In this Letter, we developed a luminescent kinase assay to perform high-throughput screening for identification of small molecule Aurora B inhibitors. Two 3,5,6-substituted indolin-2-one derivatives were identified within an in-house compound library. Their new derivatives were then designed and synthesized that resulting two new inhibitors of Aurora B kinase with improved potency. Docking simulation further demonstrated the proposed binding modes between indolin-2-one inhibitor and Aurora B.

Chemical composition of total flavonoids from Polygonum amplexicaule and their pro-apoptotic effect on hepatocellular carcinoma cells: Potential roles of suppressing STAT3 signaling.

Polygonum amplexicaule D. Don var. sinense Forb (P. amplexicaule) is a medical plant traditionally used in the treatment of malignant diseases including hepatocellular carcinoma (HCC), but the scientific basis underlying its anti-HCC activity remains poorly understood. Here, we explored the chemical profile of total flavonoids from P. amplexicaule (TFPA). Nine compounds that constituted the major components of TFPA were separated and identified. Further investigations revealed that TFPA dose-dependently induced HepG2, Huh-7 and H22 HCC cell apoptosis. In HCC cells, TFPA dramatically inhibited the transcriptional activity of signal transducer and activator of transcription 3 (STAT3). In addition, TFPA increased the expression of SHP-1, a protein tyrosine phosphatase catalyzing STAT3 dephosphorylation, in HCC cells. Animal studies showed that TFPA considerably provoked transplanted H22 cell apoptosis with undetectable toxicological effects on tumor-bearing mice. Consistently, TFPA dose-dependently inhibited transcriptional activity of STAT3 in transplanted tumor tissues. This study collectively demonstrated that TFPA has the capacity of inducing HCC cell apoptosis both in vitro and in vivo with low toxic effects on normal hepatocytes and vital organs of tumor-bearing mice. Suppressing STAT3 signaling is implicated in TFPA-mediated HCC cell apoptosis.

An improved isoprenylcysteine carboxylmethyltransferase inhibitor induces cancer cell death and attenuates tumor growth in vivo.

Inhibitors of isoprenylcysteine carboxylmethyltransferase (Icmt) are promising anti-cancer agents, as modification by Icmt is an essential component of the protein prenylation pathway for a group of proteins that includes Ras GTPases. Cysmethynil, a prototypical indole-based inhibitor of Icmt, effectively inhibits tumor cell growth. However, the physical properties of cysmethynil, such as its low aqueous solubility, make it a poor candidate for clinical development. A novel amino-derivative of cysmethynil with superior physical properties and marked improvement in efficacy, termed compound 8.12, has recently been reported. We report here that Icmt (-/-) mouse embryonic fibroblasts (MEFs) are much more resistant to compound 8.12-induced cell death than their wild-type counterparts, providing evidence that the anti-proliferative effects of this compound are mediated through an Icmt specific mechanism. Treatment of PC3 prostate and HepG2 liver cancer cells with compound 8.12 resulted in pre-lamin A accumulation and Ras delocalization from the plasma membrane, both expected outcomes from inhibition of the Icmt-catalyzed carboxylmethylation. Treatment with compound 8.12 induced cell cycle arrest, autophagy and cell death, and abolished anchorage-independent colony formation. Consistent with its greater in vitro efficacy, compound 8.12 inhibited tumor growth with greater potency than cysmethynil in a xenograft mouse model. Further, a drug combination study identified synergistic antitumor efficacy of compound 8.12 and the epithelial growth factor receptor (EGFR)-inhibitor gefitinib, possibly through enhancement of autophagy. This study establishes compound 8.12 as a pharmacological inhibitor of Icmt that is an attractive candidate for further preclinical and clinical development.

"Turn off-on" fluorescent sensor for platinum drugs-DNA interactions based on quantum dots.

A "turn off-on" mode has been established by using the interaction between platinum anticancer drugs and DNA as input signal and the fluorescence reversible change of quantum dots (QDs) as output signal. The QDs fluorescence can be quenched by platinum anticancer drugs via photo-induced electron transfer process, rendering the system into "turn off" status, and the system can then be "turned on" when fluorescence is restored due to covalent conjugation between DNA and platinum anticancer drugs. This dual-directional fluorescence change realized the detection of cisplatin and DNA, overcoming the selectivity problem commonly existed in the traditional mono-directional fluorescence detection mode. The reversible fluorescent "turn off-on" mode has been further employed to study the interactions between DNA and different platinum anticancer drugs (cisplatin, oxaliplatin and carboplatin). Furthermore, the impacts of different types of DNAs (different in base sequence, chain length and ssDNA/dsDNA) on the mode are also explored. This simple, fast and convenient spectroscopic method owns promising applications in the study on interaction between medical molecules and DNA, and in biochemical detections.