Low-dose all-trans retinoic acid enhances cytotoxicity of cisplatin and 5-fluorouracil on CD44+ cancer stem cells

Cis-diamminedichloridoplatinum(II)(CDDP)-based combination chemotherapy is frequently used in gastrointestinal cancer. The synergistic mechanism of all-trans retinoic acid (ATRA), cisplatin (CDDP) and 5-fluorouracil (5-FU) in combination remains unclear. Despite their potent antitumor properties, resistance to CDDP and 5-FU develops frequently in tumors. To clarify this mechanism, we determined the sensitivity to each drug and their combination in two gastrointestinal cancer stem cells (CSCs) subpopulation.Here, we report the identification and separation of CD44⁺ cells from human gastric carcinoma (AGS) and human esophageal squamous cell carcinoma (KYSE-30) cancer cell lines by magnetic activated cell sorting (MACS). We allowed the CD44^± cells to grow 6 days at a subtoxic concentration of ATRA and then treated with different concentration of CDDP and 5-FU for 24 h. The cytotoxicity was examined by cell proliferation MTT assay. Additionally, AO/EB staining was used for detection of apoptotic cells. In order to determine whether the growth inhibition was also associated with changes in cell cycle distribution, cell cycle analysis was performed using flow cytometry.Low concentration of ATRA (1 μM, 6days) followed by 5-FU and CDDP was found to be more effective than either drugs alone, thus resulting in synergistic cytotoxicity in Kyse-30 and AGSCD44^± cells. Furthermore, there was an indication that the combination of ATRA with 5FU and CDDP caused an increase in cell cycle arrest in G2/M and G0/G1.We conclude that low concentration of ATRA enhances the cytotoxicity of CDDP and 5FU by facilitating apoptosis and cell cycle arrest in gastrointestinal CSCs and provide a rational basis for the design of novel, well-tolerated CDDP- and 5FU-based chemotherapy in human gastrointestinal carcinoma.     

Evaluation of cisplatin-hydrogel for improving localized antitumor efficacy in gastric cancer

Gastric cancer, one of the most common disease, has become a major public health problem worldwide. Cisplatin (DDP) has been a widely used drug for the treatment of cancer, also usually applied in gastric cancer in clinic. However, the side effects including toxicity and drug-resistance restricted the usage of DDP in clinic, so we prepared a DDP-complexed hydrogel (DDP-Gel) and investigated its efficacy in gastric cancer. For in vivo studies, MKN45-Luc cells were injected into BLAB/C node mice subcutaneously to establish gastric cancer with orthotopically grown tumors. Mice bearing tumors were treated with normal saline, DDP and DDP-Gel. Body weight and survival condition were observed and recorded. The treatment efficacy in vivo was detected by luciferase imaging and histological evaluation was performed by H&E staining of different organs. Additionally, normal ICR mice were treated with different doses of DDP/DDP-Gel to calculate their LD₅₀ in vivo. The results showed that DDP-Gel prolonged survival time and ameliorated body weight changes of mice bearing tumors. DDP-Gel exhibited higher efficacy to inhibit tumor growth and metastasis, compared to DDP. Besides, LD₅₀ of DDP-Gel was 166.0?mg/kg, 13.2 folds higher than DDP. As a conclusion, DDP-Gel showed a more effective and safer function than DDP in gastric cancer, which indicating that DDP-Gel might be a novel strategy for gastric cancer therapy.     

FOLFCIS Treatment and Genomic Correlates of Response in Advanced Anal Squamous Cell Cancer

Background

Treatment of advanced anal squamous cell cancer (SCC) is usually with the combination of cisplatin and 5-fluorouracil, which is associated with heterogeneous responses across patients and significant toxicity. We examined the safety and efficacy of a modified schedule, FOLFCIS (leucovorin, fluorouracil, and cisplatin), and performed an integrated clinical and genomic analysis of anal SCC.

Platinum levels in various tissues of a patient who died 181 days after cisplatin overdosing determined by electrospray ionization mass spectrometry

Platinum (Pt) levels were determined in various tissues and body fluids obtained from a patient who died 181 days after cisplatin overdosing. The symptoms of cisplatin overdose, however, might have almost disappeared by day 40, and the patient’s death was ascribed to the recurrence of malignant lymphoma. Determination of Pt derived from cisplatin was performed by electrospray ionization mass spectrometry (ESI-MS) using silver (Ag) as internal standard. Pt and Ag complexed with diethyldithiocarbamate (DDC) in wetashed blood, and tissue solutions were extracted into isoamyl alcohol, and then acidified with oxalic acid. By injecting an aliquot of the isoamyl alcohol layer into a mass spectrometer in the direct flow injection mode, the quantitation was performed using the signals of Pt(DDC)₃ ⁺ and Ag(DDC)₂ ⁺ at m/z 639 and 403, respectively. The Pt levels ranged from 25ng/ml in blood to 2050ng/g wet weight in the liver of the patient, indicating that Pt remained at high levels in tissues, even after a period as long as 181 days after cisplatin overdosing.     

调整给药时间减轻顺铂肾毒性的研究

目的　观察不同给药时间对顺铂肾毒性的影响。　方法　 1 6例癌症患者分为两组各 8例 ,分别在上午 1 0时或下午 8时静滴 6 0mg m2 顺铂 ,3～ 4周后作第 2周期化疗时交换给药时间 ,以尿 β2 微球蛋白浓度作为肾小管功能改变的指标。　结果　治疗前两组的尿 β2 微球蛋白浓度均在 2 0 0 μg L以下。治疗后 ,上午 1 0时给药组的尿β2 微球蛋白浓度在第 1周期为 4 96± 6 6 μg L ,第 2周期为 5 0 4± 74 μg L ,下午 8时给药组分别为 2 77± 4 3μg L(t=3.6 6 ,P <0 .0 1 )和 2 83± 39μg L(t=3.6 3,P <0 .0 1 )。 　结论　不同时间给药对顺铂的肾毒性有显著影响 ,下午 8时给药可明显减轻顺铂的肾毒性。     

长春瑞滨加异环磷酰胺加顺铂治疗晚期非小细胞肺癌98例临床疗效观察

目的观察长春瑞滨(NVB)、异环磷酰胺(IFO)、顺铂(PDD)三药联合(NIP)治疗晚期非小细胞肺癌的疗效和毒性.方法共收治ⅢB～Ⅳ期非小细胞肺癌98例,其中鳞癌51例,腺癌42例,大细胞癌5例.ⅢB期59例,Ⅳ期39例.初治71例,复治27例.方案:NVB 25 mg/m2静滴,第1,8天;IFO 1.5 g/m2,静滴,第1～3天;PDD 30 mg/m2,静滴,第1～3天.4周为一周期.结果 CR 1例,PR 44例,NC 45例,PD 8例,总有效率(CR PR)为45.9%.中位缓解期8个月,中位生存期11个月,1年生存率为48.0%.骨髓抑制为剂量限制性毒性,其中Ⅲ～Ⅳ度占40.8%.结论 NIP方案是治疗晚期非小细胞肺癌有效且安全的方案.     

Sequence-dependent Termination of Mammalian DNA Polymerase Reaction by a New Platinum Compound, (–)-(R)-2-Aminomethylpyrrolidine(1,1-cyclobutane-dicarboxylato)-2-platinum(II) Monohydrate

We examined the mechanisms of the inhibition of DNA synthesis by a new platinum compound, (-)-( R )-2-aminomethylpyrrolidine(1,1-cyclobutane-dicarboxylato)-2-platinum(II) monohydrate (DWA-2114R), a derivative of the antitumor drug cis- diamminedichloroplatinum(II) (CDDP), using prokaryotic and eukaryotic DNA polymerases. Preincubating activated DNA with CDDP or DWA-2114R reduced its template activity for prokaryotic and eukaryotic DNA polymerases in a dose-dependent manner. DWA2114R required six times greater drug concentration and two times longer incubation time to show the same decrease of the template activity compared to CDDP. Treatment of primed pUC118 ssDNA templates with the two drugs followed by second-strand synthesis by prokaryotic and eukaryotic DNA polymerases revealed that DWA2114R bound to DNA in a similar manner to CDDP and these adducts blocked DNA elongation by DNA polymerases of eukaryotes as well as of prokaryotes. With these two drugs, the elongations by E. coli DNA polymerase I (Klenow fragment), T7 DNA polymerase and calf thymus DNA polymerase α were strongly arrested at guanine-guanine sequences (GG). Stop bands were also observed at adenine-guanine sequences (AG) guanine-adenine-guanine sequences (GAG) and mono-guanine sequence (G). Calf testis DNA polymerase β was also arrested efficiently at AG, GAG and G, but much more weakly at GG. This pattern was common to DWA2114R and CDDP.     

吉西他滨联合顺铂治疗晚期非小细胞肺癌的临床研究

目的 观察吉西他滨（gemcitabine，GEM）联合顺铂方案治疗晚期非小细胞肺癌的疗效及不良反应。方法 对经病理组织学或细胞学诊断证实的56例晚期非小细胞肺癌患者采用GP方案行静脉化疗：GEM1000mg／m^2，静脉滴注，d1，d8；DDP30mg／m^2，静脉滴注，d1～d3；21天重复，至少治疗2个周期。结果 可评价疗效56例，完全缓解（CR）5．3％（3／56），部分缓解（PR）42．9％（24／56），稳定（SD）33．9％（19／56），进展（PD）17．9％（10／56），总有效率（RR）48．2％（27／56）；肿瘤控制率（CR＋PR＋SD）为82．1％（46／56）；中位缓解期7．4个月，中位生存期11．3个月；不良反应以白细胞及血小板减少，消化道反应，乏力为常见，患者均可耐受，无化疗相关死亡。结论 吉西他滨联合顺铂对晚期非小细胞肺癌有较好疗效，不良反应可为患者所耐受，值得临床应用。     

靶向持续性组织间化疗治疗舌鳞癌的初步观察

目的观察靶向持续性组织间化疗治疗舌癌的疗效及安全性。方法将顺铂(缓释型)植入于10例舌癌患者癌区周围及中央,观察局部变化、全身反应与术后标本的病理结果。结果所有患者原发灶都有不同程度的缩小,部分缓解8例,无效2例(缩小约30%左右),有效率为80%。所有患者术后标本肉眼见肿块边缘药物所在区形成比较明显的纤维组织样反应;镜下见癌中央组织凝固性坏死,植入药物周围组织变性、坏死,转移淋巴结内可见部分坏死灶、组织变性。结论顺铂(缓释型)治疗舌鳞癌,疗效较好,操作简单,安全性高,毒副作用少,对转移淋巴结有一定的治疗作用。