CRM197 reverses paclitaxel resistance by inhibiting the NAC-1/Gadd45 pathway in paclitaxel-resistant ovarian cancer cells.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a new promising target for the treatment of ovarian cancer. Our previous study showed that cross-reacting material 197 (CRM197), a specific HB-EGF inhibitor, significantly reverses resistance against paclitaxel in paclitaxel-resistant ovarian cancer cells. However, the mechanism of the effect of CRM197 on the reversion of paclitaxel resistance was unclear. In this study, in vitro and in vivo data suggested that CRM197 treatment sensitized paclitaxel-resistant ovarian cancer cells to paclitaxel, at least in part, via nucleus accumbens-1 (NAC-1) and its downstream pathway, DNA damage-inducible 45-γ interacting protein (Gadd45gip1)/growth arrest and DNA damage-inducible 45 (Gadd45), in A2780/Taxol and SKOV3/Taxol cells. The results also showed that CRM197 activated the proapoptotic JNK/p38MAPK pathway to enhance caspase-3 activity and apoptosis by downregulation of the NAC-1/Gadd45gip1/Gadd45 pathway, leading to reversion of paclitaxel resistance in A2780/Taxol and SKOV3/Taxol cells. This study provides the first mechanism through which CRM197 significantly reverses resistance against paclitaxel by modulating the NAC-1/Gadd45gip1/Gadd45 pathway in paclitaxel-resistant ovarian cancer cells, and the mechanism of HB-EGF inhibition as a novel therapeutic strategy for patients with paclitaxel-resistant ovarian cancer.

An Observation of the Role of Autophagy in Patients with Endometriosis of Different Stages during Secretory Phase and Proliferative Phase.

BACKGROUND: Autophagy exists widely in various physiological and pathological conditions. Lots of investigations have verified that the autophagic activity is always related to the occurrence and the development of cancer. Endometriosis (EMs) is a disease that endometrium-like tissues abnormally grow outside the uterus and also considered to possess the characters of tumor because of its malignant biological behavior. INTRODUCTION: Recently, several studies have already revealed that autophagy may play a potential role in proliferative-phase EMs. However, the function of autophagic activity in secretory-phase EMs is still unclear. METHODS: In our work, we explored autophagic activity between normal endometrium and EMs lesion endometrium during different menstrual phases and EMs stages. The clinical endometrium samples from 73 women were selected in this study, including 30 healthy individuals and 43 patients with EMs (endometrium samples include eutopic and its matched ectopic endometrium). All the participants were divided into two groups according to the menstrual cycle, namely proliferative-phase and secretive- phase group. Among the patients with EMs, 22 individuals in proliferative phase and the other 21 individuals in secretory phase were further classified into the groups of Stage I-II and Stage III-IV according to revised-American Fertility Society (r-AFS). Two autophagy-related proteins microtubuleassociated protein 1 light chain 3 beta-II (LC3B-II) and sequestosome protein (P62), which are believed to be the indicators of autophagy activity, were chosen in the study. Immunohistochemical (IHC) staining, Western blot assay and Real-Time quantitative Polymerase Chain Reaction (RTqPCR) were used to examine the expression of LC3B-II and P62 in protein and mRNA level accordingly. RESULT: It showed that the expression of LC3B-II both in protein and mRNA level decreased and that of P62 increased in secretory phase of the healthy group (P<0.05), but showed no significant difference in ectopic and its eutopic endometrium group during proliferative and secretory phase (P>0.05). In addition, the expression of LC3B-II in ectopic endometrium group was significantly lower than that of its eutopic endometrium group (P<0.05), and the expression of P62 was significantly higher accordingly (P<0.05). At the same time, both LC3B-II and P62 levels remained same between eutopic endometrium group and control group (P>0.05). Furthermore, compared to Stage I-II EMs group, the expression of LC3B-II was significantly lower (P<0.05) and P62 was significantly higher (P<0.05) in Stage III-IV EMs during secretory phase. CONCLUSION: Taken together, the periodicity-losing in EMs and the decreased autophagic activity in ectopic endometrium may exert a potential role in the pathogenesis of EMs. Down-regulated autophagy of ectopic endometrium in secretory phase may be related to the progression of EMs.

Cross-reacting material 197 reverses the resistance to paclitaxel in paclitaxel-resistant human ovarian cancer.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) has been proven to be a promising chemotherapeutic target for ovarian cancer. Our previous studies have demonstrated that inhibition of HB-EGF by the special inhibitor, cross-reacting material 197 (CRM197), potently inhibits the anti-tumor activity in paclitaxel-resistant ovarian cancer. Here, we found that inhibition of HB-EGF by CRM197 significantly reverses the resistance to paclitaxel in paclitaxel-resistant ovarian carcinoma cell line (A2780/Taxol). A2780/Taxol cells over-expressed HB-EGF and epidermal growth factor receptor (EGFR) and CRM197 notably suppressed the expression of HB-EGF and EGFR. Experiments performed in vitro and in vivo further suggested that CRM197 markedly down-regulated the ATP-binding cassette sub-family B member 1 (ABCB1/MDR1) messenger RNA (mRNA) expression (P = 0.01), plasma membrane glycoprotein (P-gp) protein (P = 0.009), and P-gp-mediated efflux (P = 0.007) through inhibition of nuclear factor-κB (NF-κB) expression, which were classical chemoresistance-related targets with respect to paclitaxel therapy. Meanwhile, inhibition of HB-EGF enhanced caspase-3 activity to induce apoptosis via MDR1 inhibition in A2780/Taxol cells (P = 0.038). Collectively, HB-EGF is a molecular target for the resistance of ovarian cancer to paclitaxel and CRM197 as a HB-EGF-targeted agent might be a chemosensitizing agent for paclitaxel-resistant ovarian carcinoma. Our findings provide novel possible mechanisms for HB-EGF to be a target to restore the chemosensitivity to paclitaxel.

[Discussion on ultrasonographic characteristics of schistosomal appendicitis lesions].

OBJECTIVE: To discuss the ultrasonographic characteristics of schistosomal appendicitis lesions. METHODS: Among the patients with schistosomal hepatopathy who were discovered by Color Doppler ultrasound in Huzhou Central Hospital from January 2012 to December 2015, 50 cases with clear history of schistosomiasis and treatment were chosen as a schistosomal hepatopathy group, meanwhile, 50 normal people, who came from non-endemic areas, without schistosomal hepatopathy and schistosomiasis history were chosen as a control group. The two groups were examined by ultrasound scan of the appendix, and the data of the largest diameter of the appendix and the thickness of the appendix wall were collected, and the sonographic characteristics of their appendixes, such as whether the echo of the appendix wall was even or not, were observed. RESULTS: The minimum internal diameter of the appendix cavity and the thickness of the appendix wall of the schistosomal hepatopathy group were (2.090 ± 0.790) mm and (1.332 ± 0.313) mm, respectively, the former was significantly narrower than that of the control group, while the latter was significantly thicker than that of the control group (t = 2.647, - 4.526, respectively, both P＜0.05). The proportions of those with inhomogeneous echo, indistinctness structure, uneven thickening of the appendix wall, as well as having intestinal contents in the appendix cavity in the schistosomal hepatopathy group were higher than those in the control group (χ2 = 12.000, 18.537, 24.008, 4.244, respectively, all P＜0.05). CONCLUSIONS: Schistosomal appendicitis lesions have obvious ultrasonographic characteristics under ultrasound. Ultrasound can play an important role in judging whether the appendix of schistosomiasis patients is involved and discovering the lesion of appendix early.

Cross-reacting material 197, a heparin-binding EGF-like growth factor inhibitor, reverses the chemoresistance in human cisplatin-resistant ovarian cancer.

Cross-reacting material 197 (CRM197), a specific HB-EGF inhibitor, has been proven to be a promising antitumor agent for ovarian cancer therapy. Our previous studies have shown that CRM197 has potent antitumor activity in human cisplatin-resistant ovarian cancer. However, the relationship between CRM197 and the resistance to cisplatin remains unclear. Here, we report that CRM197 significantly reverses the resistance to cisplatin in cisplatin-resistant ovarian carcinoma cell line (A2780/CDDP). We established xenograft nude mice models with A2780 and A2780/CDDP cells. Notably, we observed that CRM197 suppresses the expression of HB-EGF and epidermal growth factor receptor in A2780/CDDP cells and xenografts harboring the overexpression of HB-EGF and epidermal growth factor receptor. Experiments conducted in vitro and in vivo suggest that CRM197 markedly downregulates the expression of excision repair cross-complementing group 1 (P = 0.002) and DNA repair capacity in A2780/CDDP tumor (P < 0.001) by inactivation of extracellular signal-regulated kinase signaling, providing novel possible mechanisms for the ability of CRM197 to restore drug sensitivity. These results suggest that CRM197 as an HB-EGF inhibitor might be a cisplatin-chemosensitizing agent for the treatment of ovarian carcinoma with resistance to cisplatin.

The anti-tumor effect of cross-reacting material 197, an inhibitor of heparin-binding EGF-like growth factor, in human resistant ovarian cancer.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a promising target for ovarian cancer therapy. Cross-reacting material 197 (CRM197), a specific HB-EGF inhibitor, has been proven to represent possible chemotherapeutic agent for ovarian cancer. However, the effect of CRM197 on the resistant ovarian carcinoma cells has not been sufficiently elucidated. Here, we found that HB-EGF was over-expressed in a paclitaxel-resistant human ovarian carcinoma cell line (A2780/Taxol) and a cisplatin-resistant cell line (A2780/CDDP), as well as the xenograft mouse tissue samples with these cells. To investigate the possible significance of the HB-EGF over-expression in A2780/Taxol and A2780/CDDP cells, we inhibited HB-EGF expression by CRM197 to investigate the effect of CRM197 treatment on these cells. We observed that CRM197 significantly induced anti-proliferative activity in a dose-dependent manner with the cell-cycle arrest at the G0/G1 phase and enhanced apoptosis in A2780/Taxol and A2780/CDDP cells. The sensitive ovarian carcinoma parental cell line (A2780), A2780/Taxol and A2780/CDDP cells formed tumors in nude mice, and enhanced tumorigenicity was observed in drug-resistant tumors. Furthermore, we observed that CRM197 significantly suppressed the growth of drug-resistant ovarian cancer xenografts in vivo (p<0.001). These results suggest that CRM197 as an HB-EGF-targeted agent has potent anti-tumor activity in paclitaxel- and cisplatin-resistant ovarian cancer which over-express HB-EGF.

[Reversal effect of MDR1 and MDR3 gene silencing on resistance of A2780/taxol cells to paclitaxel].

OBJECTIVE: To investigate the reversal effect of MDR1 and MDR3 gene silencing on resistance of A2780/taxol cells to paclitaxel. METHODS: shRNA plasmid vector specifically targeting MDR1 and MDR3 genes was transfected into A2780/taxol cells. The early stage cell apoptosis and the effect of intracellular rhodamine 123 (Rh123) accumulation were detected by flow cytometry (FCM). The late stage cell apoptosis rate was detected by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL). The 50% inhibition concentration (IC(50)) of paclitaxel on A2780/taxol cells was determined by methyl thiazolyl tetrazolium (MTT) assay. MDR1 and MDR3 mRNA were assessed by RT-PCR, and caspase-3 protein was detected by western blot. RESULTS: After treatment with MDR1 and MDR3 shRNA plasmid vector, early apoptosis rate of A2780/taxol cells was (20.21 +/- 0.56)% and (10.87 +/- 1.24)%, respectively. MDR1 and MDR3 shRNA could increase cellular Rh123 accumulation (116.6 +/- 8.1 and 98.4 +/- 3.8, respectively). The late stage apoptosis rates detected by TUNEL displayed the same tendency as FCM results did. The IC(50) for paclitaxel of A2780/taxol cells was decreased significantly. The mRNA levels of MDR1 and MDR3 in A2780/taxol cells were decreased by (73.3 +/- 0.8)% and (51.6 +/- 0.4)% of control, and the reduction of MDR1 and MDR3 mRNA was in a time-dependent manner. The expression of caspase-3 protein of MDR1 and MDR3 shRNA vector transfected group in A2780/taxol cells was significantly increased [(80.8 +/- 2.6)% and (72.0 +/- 4.7)%, respectively]. CONCLUSION: MDR1 and MDR3 gene silencing could recover sensitivity of A2780/taxol cells to paclitaxel and induce cell apoptosis, thus reversing cell resistance to paclitaxel.