N6-methyladenosine-modified circPLPP4 sustains cisplatin resistance in ovarian cancer cells via PIK3R1 upregulation.

BACKGROUND: Cisplatin (CDDP) is the first-line chemotherapeutic strategy to treat patients with ovarian cancer (OC). The development of CDDP resistance remains an unsurmountable obstacle in OC treatment and frequently induces tumor recurrence. Circular RNAs (circRNAs) are noncoding RNAs with important functions in cancer progression. Whether circRNAs function in CDDP resistance of OC is unclear. METHODS: Platinum-resistant circRNAs were screened via circRNA deep sequencing and examined using in situ hybridization (ISH) in OC. The role of circPLPP4 in CDDP resistance was assessed by clone formation and Annexin V assays in vitro, and by OC patient-derived xenografts and intraperitoneal tumor models in vivo. The mechanism underlying circPLPP4-mediated activation of miR-136/PIK3R1 signaling was examined by luciferase reporter assay, RNA pull-down, RIP, MeRIP and ISH. RESULTS: circPLPP4 was remarkably upregulated in platinum resistant OC. circPLPP4 overexpression significantly enhanced, whereas circPLPP4 silencing reduced, OC cell chemoresistance. Mechanistically, circPLPP4 acts as a microRNA sponge to sequester miR-136, thus competitively upregulating PIK3R1 expression and conferring CDDP resistance. The increased circPLPP4 level in CDDP-resistant cells was caused by increased RNA stability, mediated by increased N6-methyladenosine (m6A) modification of circPLPP4. In vivo delivery of an antisense oligonucleotide targeting circPLPP4 significantly enhanced CDDP efficacy in a tumor model. CONCLUSIONS: Our study reveals a plausible mechanism by which the m6A -induced circPLPP4/ miR-136/ PIK3R1 axis mediated CDDP resistance in OC, suggesting that circPLPP4 may serve as a promising therapeutic target against CDDP resistant OC. A circPLPP4-targeted drug in combination with CDDP might represent a rational regimen in OC.

FoxG1/BNIP3 axis promotes mitophagy and blunts cisplatin resistance in osteosarcoma.

Cisplatin (CDDP) is a commonly used chemotherapeutic for osteosarcoma (OS) patients, and drug resistance remains as a major hurdle to undermine the treatment outcome. Here, we investigated the potential involvement of FoxG1 and BNIP3 in CDDP resistance of OS cells. FoxG1 and BNIP3 expression levels were detected in the CDDP-sensitive and CDDP-resistant OS tumors and cell lines. Mitophagy was observed through transmission electron microscope analysis. The sensitivity to CDDP in OS cells upon FoxG1 overexpression was examined in cell and animal models. We found that FoxG1 and BNIP3 showed significant downregulation in the CDDP-resistant OS tumor samples and cell lines. CDDP-resistant OS tumor specimens and cells displayed impaired mitophagy. FoxG1 overexpression promoted BNIP3 expression, enhanced mitophagy in CDDP-resistant OS cells, and resensitized the resistant cells to CDDP treatment in vitro and in vivo. Our data highlighted the role of the FoxG1/BNIP3 axis in regulating mitophagy and dictating CDDP resistance in OS cells, suggesting targeting FoxG1/BNIP3-dependent mitophagy as a potential strategy to overcome CDDP resistance in OS.

Ultrasound-Mediated Lysozyme Microbubbles Targeting NOX4 Knockdown Alleviate Cisplatin-Exposed Cochlear Hair Cell Ototoxicity.

The nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) protein plays an essential role in the cisplatin (CDDP)-induced generation of reactive oxygen species (ROS). In this study, we evaluated the suitability of ultrasound-mediated lysozyme microbubble (USMB) cavitation to enhance NOX4 siRNA transfection in vitro and ex vivo. Lysozyme-shelled microbubbles (LyzMBs) were constructed and designed for siNOX4 loading as siNOX4/LyzMBs. We investigated different siNOX4-based cell transfection approaches, including naked siNOX4, LyzMB-mixed siNOX4, and siNOX4-loaded LyzMBs, and compared their silencing effects in CDDP-treated HEI-OC1 cells and mouse organ of Corti explants. Transfection efficiencies were evaluated by quantifying the cellular uptake of cyanine 3 (Cy3) fluorescein-labeled siRNA. In vitro experiments showed that the high transfection efficacy (48.18%) of siNOX4 to HEI-OC1 cells mediated by US and siNOX4-loaded LyzMBs significantly inhibited CDDP-induced ROS generation to almost the basal level. The ex vivo CDDP-treated organ of Corti explants of mice showed an even more robust silencing effect of the NOX4 gene in the siNOX4/LyzMB groups treated with US sonication than without US sonication, with a marked abolition of CDDP-induced ROS generation and cytotoxicity. Loading of siNOX4 on LyzMBs can stabilize siNOX4 and prevent its degradation, thereby enhancing the transfection and silencing effects when combined with US sonication. This USMB-derived therapy modality for alleviating CDDP-induced ototoxicity may be suitable for future clinical applications.

The tumor cell-intrinsic cGAS-STING pathway is associated with the high density of CD8+ T cells after chemotherapy in esophageal squamous cell carcinoma.

BACKGROUND: Chemotherapy has the potential to induce CD8+ T-cell infiltration in the tumor microenvironment (TME) and activate the anti-tumor immune response in several cancers including esophageal squamous cell carcinoma (ESCC). The tumor cell-intrinsic cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has been known as a critical component for regulating immune cell activation in the TME. However, its effect on the infiltration of immune cells induced by chemotherapy in the ESCC TME has not been investigated. METHODS: We examined the effect of the tumor-cell intrinsic cGAS-STING pathway on the infiltration of CD8+ T cells induced by chemotherapy in ESCC using ESCC cell lines and surgically resected ESCC specimens from patients who received neoadjuvant chemotherapy (NAC). RESULTS: We found that chemotherapeutic agents, including 5-fluorouracil (5-FU) and cisplatin (CDDP), activated the cGAS-STING pathway, consequently inducing the expression of type I interferon and T-cell-attracting chemokines in ESCC cells. Moreover, the tumor cell-intrinsic expression of cGAS-STING was significantly and positively associated with the density of CD8+ T cells in ESCC after NAC. However, the tumor cell-intrinsic expression of cGAS-STING did not significantly impact clinical outcomes in patients with ESCC after NAC. CONCLUSION: Our findings suggest that the tumor cell-intrinsic cGAS-STING pathway might contribute to chemotherapy-induced immune cell activation in the ESCC TME.

Melatonin and cisplatin co-treatment against cancer: A mechanistic review of their synergistic effects and melatonin's protective actions.

Combination chemotherapy appears to be a preferable option for some cancer patients, especially when the medications target multiple pathways of oncogenesis; individuals treated with combination treatments may have a better prognosis than those treated with single agent chemotherapy. However, research has revealed that this is not always the case, and that this technique may just enhance toxicity while having little effect on boosting the anticancer effects of the medications. Cisplatin (CDDP) is a chemotherapeutic medicine that is commonly used to treat many forms of cancer. However, it has major adverse effects such as cardiotoxicity, skin necrosis, testicular toxicity, and nephrotoxicity. Many research have been conducted to investigate the effectiveness of melatonin (MLT) as an anticancer medication. MLT operates in a variety of ways, including decreasing cancer cell growth, causing apoptosis, and preventing metastasis. We review the literature on the role of MLT as an adjuvant in CDDP-based chemotherapies and discuss how MLT may enhance CDDP's antitumor effects (e.g., by inducing apoptosis and suppressing metastasis) while protecting other organs from its adverse effects, such as cardio- and nephrotoxicity.

Compound Danshen dripping pills prevent early diabetic retinopathy: roles of vascular protection and neuroprotection.

Introduction: Diabetic retinopathy (DR) represents a major cause of adult blindness, and early discovery has led to significant increase in the number of patients with DR. The drugs currently used for treatment, such as ranibizumab, mainly focus on the middle and late periods of DR, and thus do not meet the clinical need. Here, the potential mechanisms by which compound Danshen Dripping Pills (CDDP) might protect against early DR were investigated. Methods: Db/db mice were used to establish a DR model. The initial weights and HbA1c levels of the mice were monitored, and retinal pathology was assessed by hematoxylin-eosin (HE) staining. The vascular permeability of the retina and thickness of each retinal layer were measured, and electroretinogram were performed together with fundus fluorescein angiography and optical coherence tomography. The levels of inflammatory factors were examined in retinal tissue, as well as those of intercellular adhesion molecule 1 (ICAM-1), IL-6, and monocyte chemoattractant protein 1 (MCP-1) in the serum using ELISA. Immunohistochemistry was used to evaluate levels of vascular endothelial growth factor (VEGF), B-cell lymphoma 2 (Bcl-2), and Bclassociated X protein (Bax). Retinal cell injury and apoptosis were examined by TdT-mediated dUTP Nick End Labeling (TUNEL) assays. Results: The data showed that CDDP significantly improved cellular disarrangement. Imaging data indicated that CDDP could reduce vascular permeability and the amplitude of oscillatory potentials (OPs), and restore the thickness of the ganglion cell layer. Moreover, CDDP reduced the expression levels of inflammatory factors in both the retina and serum. Conclusion: These findings strongly suggest that CDDP prevents early DR through vascular and neuroprotection.

The role and mechanism of IFITM1 in developing acquired cisplatin resistance in small cell lung cancer.

Platinum-based chemotherapies, historically the cornerstone of first-line treatment for small-cell lung cancer (SCLC), face a major hurdle: the frequent emergence of chemoresistance, notably to cisplatin (CDDP). Current understanding of the mechanisms driving CDDP resistance in SCLC is incomplete. Notably, Interferon inducible transmembrane protein1 (IFITM1) has been identified as a key player in the distant metastasis of SCLC. Analysis of The Cancer Genome Atlas (TCGA) database revealed that IFITM1 expression is markedly elevated in tumor tissues as compared to that from adjacent normal tissues, correlating with a worse prognosis for patients with SCLC. Our research focused on investigating the role of IFITM1 in the acquisition of cisplatin resistance in SCLC. Further clinical sample analysis highlighted a significant increase in IFITM1 levels in SCLC tissues from cisplatin-resistant patients versus those were responsive to CCDP treatment, with similar trends observed in cisplatin-resistant SCLC cells. Crucially, overexpression of IFITM1 reduced the sensitivity of SCLC cells to cisplatin, while silencing IFITM1 enhanced chemosensitivity in cisplatin-resistant strains. Our in vivo studies further confirmed that silencing IFITM1 significantly boosted the efficacy of cisplatin in inhibiting growth of subcutaneous tumors of NCI-H466/CDDP cells (cisplatin-resistant SCLC cells) in a mouse model. Mechanistically, IFITM1 appears to foster cisplatin resistance through activation of the Wnt/ß-catenin pathway. In summary, our findings suggest that targeting IFITM1, alongside cisplatin treatment, could offer a promising therapeutic strategy to overcome resistance and improve outcomes for SCLC patients.

Autophagy Inhibition and Sensitization to Cisplatin in Esophageal Cancer Stem-Like Cells via All-trans Retinoic Acid-induced miR-30a.

AIM: Providing insights into the chemoresistance of esophageal squamous cell carcinoma (ESCC) and its dependence on chemotherapy-induced autophagy. BACKGROUND: Autophagy is induced during chemotherapy of cancer cells, promoting resistance to anti-cancer treatments. OBJECTIVE: The objective of this study is to investigate the modulation of microRNA-30a (miR-30a), a known regulator of autophagy, in ESCC cells by all-trans retinoic acid (ATRA). METHODS: Treatment involved ESCC cells KYSE-30 and TE8 with cis-dichloro-diamine platinum (CDDP), enriching CDDP-surviving cells (CDDP-SCs). qRT-PCR and dual luciferase reporter assay (DLRA) were employed to evaluate miR-30a expression and its interaction with Beclin-1 (BECN1) in both CDDP-SCs and those treated with ATRA. RESULTS: Chemotherapy using CDDP led to a significant decrease in miR-30a expression within ESCC cells. Increased autophagy levels were identified in cancer cells exhibiting stem cell-like properties, characterized by the overexpression of specific stem cell markers. These results suggest that the downregulation of miR-30a induced by CDDP treatment may represent a potential underlying mechanism for increased autophagic activity, as evidenced by the upregulation of autophagy-related proteins, such as BECN1 and an elevated LC3-II/LC3-I ratio. ATRA treatment elevated miR-30a expression and disrupted hallmark cancer stem cell (CSC) features in ESCC cells. Further investigations demonstrated that increased miR-30a expression led to a reduction in the expression of its target gene, BECN1, and attenuated BECN1-mediated autophagy. This resulted in an augmentation of CDDP-induced apoptosis in ESCC cells and a G2/M cell cycle arrest. CONCLUSION: CDDP chemotherapy reduced miR-30a, promoting ESCC cell resistance through autophagy and CSC-like features, a process that may be modulated by ATRA.

Long term survival in adult osteosarcoma patients treated with a two-drug regimen: Final results of the OSAD93 phase II study of the FSG-GETO.

RATIONALE: We report a phase II trial (OSAD93) testing CDDP with ifosfamide (IFO), without doxorubicin in neoadjuvant phase, in adult osteosarcoma with a 25 years follow-up. PATIENTS AND METHODS: This is a multicentric phase II study of neoadjuvant chemotherapy with IFO and CDDP in localized high-grade osteosarcoma of patients. Patients received 4 pre-operative courses of IFO 9 g/m2 and CDDP 100 mg/m2 on day 4 (SHOC regimen), followed by local treatment. Doxorubicin was added post-operatively (HOCA regimen) in patients with > 10 % residual tumor cells. A Good Histological Response (GHR), ie ≤ 10 % residual tumor cells in > 30 % of patients, was the primary objective. Disease-free survival (DFS), overall survival (OS) and toxicity were secondary objectives. RESULTS: From Jan 1994 to Jun 1998, 60 patients were included. Median age was 27 (range: 16-63). Primary tumor sites were limbs (76 %), trunk, head or neck (24 %). After neoadjuvant SHOC, grade 3-4 and febrile neutropenia, thrombopenia, and re-hospitalization occurred in 58 %, 17 %, 17 % and 22 % of SHOC courses and in 76 %, 28 %, 47 %, 47 % of HOCA courses, respectively. GHR was obtained in 16/60 (27.5 %) patients. With a median follow-up of 322 months, the DFS and OS were 51.8 % and 64.4 % at 5 years. At 10 years, DFS and OS were 49.9 % and 64.4 %. At 25 years, DFS and OS were 47.8 % and 55.9 %. No long-term cardiac toxicity was observed. Three patients developed a second malignancy (one fatal) after 300 months. CONCLUSION: Though the primary endpoint of OSAD93 was not met, this pre-operative doxorubicin-free regimen led to excellent long-term survival with limited toxicity in localized osteosarcoma.

EIF4A3-mediated biogenesis of circSTX6 promotes bladder cancer metastasis and cisplatin resistance.

BACKGROUND: Cisplatin (CDDP)-based chemotherapy is a standard first-line treatment for metastatic bladder cancer (BCa) patients, and chemoresistance remains a major challenge in clinical practice. Circular RNAs (circRNAs) have emerged as essential regulators in carcinogenesis and cancer progression. However, the role of circRNAs in mediating CDDP chemosensitivity has yet to be well elucidated in BCa. METHODS: CircSTX6 (hsa_circ_0007905) was identified by mining the public circRNA datasets and verified by Sanger sequencing, agarose gel electrophoresis, RNase R treatment and qRT-PCR assays. Then, function experiments were performed to evaluate the effects of circSTX6 on BCa metastasis. Luciferase reporter assay, RNA pull-down, RNA immunoprecipitation (RIP), RNA stability assay, Fluorescence in situ hybridization (FISH) and Immunofluorescence (IF) were conducted to evaluate the interaction among circSTX6, miR-515-3p, PABPC1 and SUZ12. Animal experiments were performed to explore the function of circSTX6 in tumor metastasis and CDDP sensitivity. RESULTS: We identified that circSTX6 was significantly upregulated in clinical samples and cells of BCa. Functionally, circSTX6 promoted cell migration and invasion both in vitro and in vivo. Mechanistically, circSTX6 could act as a miR-515-3p sponge and abolish its effect on SUZ12. Moreover, circSTX6 was confirmed to increase the stability of SUZ12 mRNA by interacting with a mRNA stabilizer PABPC1 and subsequently promote the expression of SUZ12. Importantly, silencing of circSTX6 improved the chemosensitivity of CDDP-resistant bladder cancer cells to CDDP. Furthermore, in vivo analysis supported that knockdown of circSTX6 attenuated CDDP resistance in BCa tumors. CONCLUSION: These studies demonstrate that circSTX6 plays a pivotal role in BCa metastasis and chemoresistance, and has potential to serve as a therapeutic target for treatment of BCa.

HGFK1 Enhances the Anti-Tumor Effects of Angiogenesis Inhibitors via Inhibition of CD90+ CSCs in Hepatocellular Carcinoma.

The combination of anti-angiogenesis agents with immune-checkpoint inhibitors is a promising treatment for patients with advanced hepatocellular carcinoma (HCC); however, therapeutic resistance caused by cancer stem cells present in tumor microenvironments remains to be overcome. In this study, we report for the first time that the Kringle 1 domain of human hepatocyte growth-factor α chain (HGFK1), a previously described anti-angiogenesis peptide, repressed the sub-population of CD90+ cancer stem cells (CSCs) and promoted their differentiation and chemotherapy sensitivity mainly through downregulation of pre-Met protein expression and inhibition of Wnt/ß-catenin and Notch pathways. Furthermore, we showed that the i.p. injection of PH1 (a tumor-targeted and biodegradable co-polymer), medicated plasmids encoding Endostatin (pEndo), HGFK1 genes (pEndo), and a combination of 50% pEndo + 50% pHGFK1 all significantly suppressed tumor growth and prolonged the survival of the HCC-bearing mice. Importantly, the combined treatment produced a potent synergistic effect, with 25% of the mice showing the complete clearance of the tumor via a reduction in the microvessel density (MVD) and the number of CD90+ CSCs in the tumor tissues. These results suggest for the first time that HGFK1 inhibits the CSCs of HCC. Furthermore, the combination of two broad-spectrum anti-angiogenic factors, Endo and HGFK1, is the optimal strategy for the development of effective anti-HCC drugs.

Audiological profile of patients treated for childhood cancer / Perfil audiológico de pacientes tratados de câncer na infância

Abstract Objective: To characterize the hearing loss after cancer treatment, according to the type of treatment, with identification of predictive factors. Methods: Two hundred patients who had cancer in childhood were prospectively evaluated. The mean age at diagnosis was 6 years, and at the audiometric assessment, 21 years. The treatment of the participants included chemotherapy without using platinum derivatives or head and neck radiotherapy in 51 patients; chemotherapy using cisplatin without radiotherapy in 64 patients; head and neck radiotherapy without cisplatin in 75 patients; and a combined treatment of head and neck radiotherapy and chemotherapy with cisplatin in ten patients. Patients underwent audiological assessment, including pure tone audiometry, speech audiometry, and immittancemetry. Results: The treatment involving chemotherapy with cisplatin caused 41.9% and 47.3% hearing loss in the right and left ear, respectively, with a 11.7-fold higher risk of hearing loss in the right ear and 17.6-fold higher in the left ear versus patients not treated with cisplatin (p < 0.001 and p < 0.001, respectively). Children whose cancer diagnosis occurred after the age of 6 have shown an increased risk of hearing loss vs. children whose diagnosis occurred under 6 years of age (p = 0.02). Conclusion: The auditory feature found after the cancer treatment was a symmetrical bilateral sensorineural hearing loss. Chemotherapy with cisplatin proved to be a risk factor, while head and neck radiotherapy was not critical for the occurrence of hearing loss.

Resumo Objetivo: Caracterizar as alterações auditivas após o tratamento do câncer, segundo o tipo de tratamento identificando os fatores preditivos. Método: Foram avaliados prospectivamente duzentos pacientes que tiveram cancer na infância. A idade média ao diagnóstico foi de 6 anos e à avaliação audiométrica de 21 anos de idade. O tratamento incluiu quimioterapia sem uso de derivados de platina ou radioterapia em cabeça e pescoço em 51 pacientes; quimioterapia com uso de cisplatina sem radioterapia em 64 pacientes; radioterapia em cabeça e pescoço sem cisplatina em 75 pacientes; e 10 pacientes receberam o tratamento combinado de radioterapia em cabeça e pescoço e quimioterapia com cisplatina. Os pacientes foram submetidos à avaliação audiológica incluindo audiometria tonal, audiometria vocal e imitanciometria. Resultados: O tratamento envolvendo quimioterapia com cisplatina levou a 41,9% e 47,3% de perda auditiva na orelha direita e esquerda, respectivamente, apresentando risco 11,7 vezes maior de desenvolver perda auditiva na orelha direita e 17,6 vezes na orelha esquerda do que aqueles que não receberam cisplatina (p < 0,001 e p < 0,001; respectivamente). Crianças cujo diagnóstico do câncer ocorreu após os 6 anos de idade mostraram maior risco de apresentar perda auditiva do que crianças menores do que 6 anos de idade (p = 0,02). Conclusão: A característica audiológica encontrada após tratamento oncológico foi perda auditiva sensorioneural bilateral simétrica. A quimioterapia com cisplatina mostrou ser fator de risco, enquanto a radioterapia em cabeça e pescoço não foi determinante para aquisição da perda auditiva.