Over expression of hRad9 protein correlates with reduced chemosensitivity in breast cancer with administration of neoadjuvant chemotherapy

CENPF knockdown inhibits adriamycin chemoresistance in triple-negative breast cancer via the Rb-E2F1 axis

Drug resistance occurs frequently in triple-negative breast cancer (TNBC) and leads to early relapse and short survival. Targeting the DNA damage response (DDR) has become an effective strategy for overcoming TNBC chemoresistance. CENPF (centromere protein) is a key regulator of cell cycle progression, but its role in TNBC chemotherapy resistance remains unclear. Here, we found that CENPF, which is highly expressed in TNBC, is associated with a poor prognosis in patients receiving chemotherapy. In addition, in vitro CENPF knockdown significantly increased adriamycin (ADR)-induced cytotoxicity in MDA-MB-231 cells and ADR-resistant cells (MDA-MB-231/ADR). Then, we demonstrated that CENPF targets Chk1-mediated G2/M phase arrest and binds to Rb to compete with E2F1 in TNBC. Considering the crucial role of E2F1 in the DNA damage response and DNA repair, a novel mechanism by which CENPF regulates the Rb-E2F1 axis will provide new horizons to overcome chemotherapy resistance in TNBC.

Cardiolipin for Enhanced Cellular Uptake and Cytotoxicity of Thermosensitive Liposome-Encapsulated Daunorubicin toward Breast Cancer Cell Lines

Daunorubicin (DNR) and cardiolipin (CL) were co-delivered using thermosensitive liposomes (TSLs). 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1-myristoyl-2-stearoyl-sn-glycero-3-phosphocholine (MSPC), cholesterol, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] or DSPE-mPEG (2000) and CL were used in the formulation of liposomes at a molar ratio of 57:40:30:3:20, respectively. CL forms raft-like microdomains that may relocate and change lipid organization of the outer and inner mitochondrial membranes. Such transbilayer lipid movement eventually leads to membrane permeabilization. TSLs were prepared by thin-film hydration (drug:lipid ratio 1:5) where DNR was encapsulated within the aqueous core of the liposomes and CL acted as a component of the lipid bilayer. The liposomes exhibited high drug encapsulation efficiency (>90%), small size (~115 nm), narrow size distribution (polydispersity index ~0.12), and a rapid release profile under the influence of mild hyperthermia. The liposomes also exhibited ~4-fold higher cytotoxicity against MDA-MB-231 cells compared to DNR or liposomes similar to DaunoXome® (p < 0.001). This study provides a basis for developing a co-delivery system of DNR and CL encapsulated in liposomes for treatment of breast cancer.

HUS1 as a Potential Therapeutic Target in Urothelial Cancer

Platinum-based chemotherapy is the standard of care with concern to first-line systemic therapy for metastatic disease in urothelial cancer (UC). Resistance to chemotherapy despite an initial response is linked with the ability to remove platinum-based DNA adducts and to repair chemotherapy-induced DNA lesions by various DNA repair proteins. The Rad9-Rad1-HUS1 complex that is loaded onto DNA at sites of damage is involved in checkpoint activation as well as DNA repair. Here, we addressed for the first time the potential influence of HUS1 expression in urothelial carcinogenesis (using two human basal urothelial cancer cell lines UM-UC-3 and HT1197) and its role as a potential therapeutic target for predicting responses to platinum-based chemotherapy. Specific inhibition of HUS1 expression in both cell lines was achieved by specific siRNA and validated by Western blot. In order to define the possible importance of HUS1 in the regulation of cellular proliferation, parental and resistant cells were treated with increasing concentrations of either control or HUS1 siRNA. HUS1 protein expression was observed in both human basal urothelial cancer cell lines UM-UC-3 and HT1197. In cisplatin-sensitive cells, knock-down of HUS1 inhibited cellular proliferation in the presence of cisplatin. On the contrary, knock-down of HUS1 in resistant cells did not result in a re-sensitization to cisplatin. Finally, RNAseq data from the Cancer Genome Atlas provided evidence that HUS1 expression is a significant prognostic factor for poor survival in UC patients. In summary, HUS1 may acts as an oncogene in UC and might be a key determinant of the cellular response to cisplatin-based chemotherapy.

DNA methylation molecular subtypes for prognosis prediction in lung adenocarcinoma

Aims

Lung cancer is one of the main results in tumor-related mortality. Methylation differences reflect critical biological features of the etiology of LUAD and affect prognosis.

Methods

In the present study, we constructed a prediction prognostic model integrating various DNA methylation used high-throughput omics data for improved prognostic evaluation.

Results

Overall 21,120 methylation sites were identified in the training dataset. Overall, 237 promoter genes were identified by genomic annotation of 205 CpG loci. We used Akakike Information Criteria (AIC) to obtain the validity of data fitting, but to prevent overfitting. After AIC clustering, specific methylation sites of cg19224164 and cg22085335 were left. Prognostic analysis showed a significant difference among the two groups (P = 0.017). In particular, the hypermethylated group had a poor prognosis, suggesting that these methylation sites may be a marker of prognosis.

Conclusion

The model might help in the identification of unknown biomarkers in predicting patient prognosis in LUAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01924-0.

APE2 Is a General Regulator of the ATR-Chk1 DNA Damage Response Pathway to Maintain Genome Integrity in Pancreatic Cancer Cells

The maintenance of genome integrity and fidelity is vital for the proper function and survival of all organisms. Recent studies have revealed that APE2 is required to activate an ATR-Chk1 DNA damage response (DDR) pathway in response to oxidative stress and a defined DNA single-strand break (SSB) in Xenopus laevis egg extracts. However, it remains unclear whether APE2 is a general regulator of the DDR pathway in mammalian cells. Here, we provide evidence using human pancreatic cancer cells that APE2 is essential for ATR DDR pathway activation in response to different stressful conditions including oxidative stress, DNA replication stress, and DNA double-strand breaks. Fluorescence microscopy analysis shows that APE2-knockdown (KD) leads to enhanced γH2AX foci and increased micronuclei formation. In addition, we identified a small molecule compound Celastrol as an APE2 inhibitor that specifically compromises the binding of APE2 but not RPA to ssDNA and 3′-5′ exonuclease activity of APE2 but not APE1. The impairment of ATR-Chk1 DDR pathway by Celastrol in Xenopus egg extracts and human pancreatic cancer cells highlights the physiological significance of Celastrol in the regulation of APE2 functionalities in genome integrity. Notably, cell viability assays demonstrate that APE2-KD or Celastrol sensitizes pancreatic cancer cells to chemotherapy drugs. Overall, we propose APE2 as a general regulator for the DDR pathway in genome integrity maintenance.

miR‑125a‑5p reverses epithelial‑mesenchymal transition and restores drug sensitivity by negatively regulating TAFAZZIN signaling in breast cancer

MicroRNA (miR)‑125a‑5p represses tafazzin phospholipid‑lysophospholipid transacylases (TAFAZZIN) expression and inhibits the epithelial‑mesenchymal transition (EMT) of ovarian cancer cells. EMT was found to have a crucial role in the acquisition of chemoresistance. Thus, the present study aimed to determine whether miR‑125a‑5p reverses EMT and restores drug sensitivity by negatively regulating TAFAZZIN in breast cancer. The expression of miR‑125a‑5p/TAFAZZIN and its association with chemotherapy response were determined in tissue samples from patients with breast cancer. Furthermore, the effects of miR‑125a‑5p on breast cancer cells were elucidated using cell proliferation and cell apoptosis assays. Then, the regulatory mechanism of miR‑125a‑5p in breast cancer was investigated by reverse transcription‑quantitative PCR, western blotting, dual‑luciferase reporter and RNA immunoprecipitation assays. The results demonstrated that miR‑125a‑5p inhibited the EMT of MCF‑7/adriamycin (Adr) breast cancer cells, as well as decreased the proliferation and increased the apoptosis of breast cancer cells treated with Adr/docetaxel. In addition, miR‑125a‑5p downregulated the expression levels of TAFAZZIN, Transglutaminase 2, phosphorylated‑AKT, N‑cadherin, vimentin and proliferating cell nuclear antigen, and significantly increased those of E‑cadherin, cleaved caspase-3 and Bax in MCF7/Adr cells. Similar results were obtained with small interfering RNA‑TAFAZZIN. Moreover, TAFAZZIN was identified as a direct target of miR‑125a‑5p in MCF7/Adr breast cancer cells. In addition, increased miR‑125a‑5p expression was observed in breast tumors from patients exhibiting a chemotherapy response, and TAFAZZIN mRNA expression was elevated in patients with no chemotherapy response. Hence, miR‑125a‑5p expression was negatively correlated with TAFAZZIN mRNA expression in breast cancer tissues. All these data suggested that miR‑125a‑5p reverses EMT and restores drug sensitivity by negatively regulating TAFAZZIN in breast cancer and, therefore, has potential as a novel therapeutic target for this disease.

The Role of CHK1 Varies with the Status of Oestrogen-receptor and Progesterone-receptor in the Targeted Therapy for Breast Cancer

Objective: The therapeutic effects of the checkpoint kinase 1 (CHK1)-targeted inhibition in tumor therapy have been confirmed, but how to choose an effective application method in breast cancer with heterogeneous molecular characteristics has remained unclear.

Methods: We evaluated the status of CHK1 in breast cancer using the cancer genome atlas database. Chemosensitivity and single-agent antitumor activity of CHK1 inhibition were measured by drug sensitivity assay, cell proliferation assay, cell cycle and apoptosis analysis in breast cancer with different ER/PR status. And based on the conjoint transcriptome atlas analyses, the corresponding mechanism were explored.

Results: In ER^-/PR^-/HER2^- breast cancer, CHK1 inhibition enhanced adriamycin (ADR) chemosensitivity which was mediated by the mitotic checkpoint complex (MCC)-anaphase-promoting complex/cyclosome (APC/C)-cyclin B1 axis, Msh homeobox 2 (MSX2) and Bcl-2-like protein 11 (BIM). However, in ER⁺/PR⁺/HER2^- breast cancer, because of the significant suppression for centromere protein F (CENPF)-mediated transcriptional activation of CHK1 induced by ADR itself, CHK1 inhibition fails to sensitize ADR toxicity. Interestingly, CHK1 inhibition showed the single-agent antitumor activity in ER⁺/PR⁺/HER2^- breast cancer which was mediated by the cyclin dependent kinase inhibitor 1A (p21), kinesin family member 11 (Eg5) and cell surface death receptor (Fas).

Conclusions: CHK1's variable role determines the application of CHK1 inhibition in breast cancer with ER/PR heterogeneity.

Evaluation of breast carcinoma regression after preoperative chemotherapy by label-free multiphoton imaging and image analysis

Neoadjuvant chemotherapy is increasingly being used in breast carcinoma as it significantly improves the prognosis and consistently leads to an increased rate of breast preservation. How to accurately assess tumor response after treatment is a crucial factor for developing reasonable therapeutic strategy. In this study, we were in an attempt to monitor tumor response by multimodal multiphoton imaging including two-photon excitation fluorescence and second-harmonic generation imaging. We found that multiphoton imaging can identify different degrees of tumor response such as a slight, significant, or complete response and can detect morphological alteration associated with extracellular matrix during the progression of breast carcinoma following preoperative chemotherapy. Two quantitative optical biomarkers including tumor cellularity and collagen content were extracted based on automatic image analysis to help monitor changes in tumor and its microenvironment. Furthermore, tumor regression grade diagnosis was tried to evaluate by multiphoton microscopy. These results may offer a basic framework for using multiphoton microscopic imaging techniques as a helpful diagnostic tool for assessing breast carcinoma response after presurgical treatment.

HUS1 checkpoint clamp component (HUS1) is a potential tumor suppressor in primary hepatocellular carcinoma

The HUS1 checkpoint clamp component (HUS1), which is a member of an evolutionarily conserved, genotoxin-activated checkpoint complex (Rad9-Rad1-Hus1 [9-1-1] complex), is involved in cell cycle arrest and DNA repair in response to DNA damage. We conducted this study to investigate the biological significances of HUS1 expression in hepatocellular carcinoma (HCC) development. The mRNA and protein expression levels of HUS1 were determined using Real-time PCR and Western blot, respectively. One hundered and twenty four paraffin sections from HCC tissues were analyzed by immunohistochemistry to assess the association between HUS1 expression and clinicopathological characteristics of patients. The Kaplan-Meier method was performed to calculate the OS and RFS curves. Cell proliferation and colony formation assays, cell migration and invasion assays and cell cycle assays were used to determine the suppressor role of HUS1 in vitro. A mouse model was used to determine the effect of HUS1 on tumorigenesis. The expression of HUS1 was significantly decreased in HCC cell lines and tissues, and low HUS1 expression was associated with poor prognosis of HCC patients. Upregulation of HUS1 expression inhibited the cell proliferation, colony formation, migration, and invasion, as well as arrested cell cycle at G0/G1 in HCC cells in vitro. Moreover, sufficient HUS1 expression inhibited the tumor growth in nude mice. Our study revealed for the first time that HUS1 is a potential tumor suppressor that might produce an antitumor effect in human HCC. Furthermore, HUS1 may serve as a prognostic indicator and could be used for therapeutic application in HCC patients.

Alterations of biomarker profiles after neoadjuvant chemotherapy in breast cancer: tumor heterogeneity should be taken into consideration

Tumor biomarkers including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67 are routinely tested in breast cancer patients and their status guides clinical management and predicts prognosis. A few retrospective studies have suggested that neoadjuvant chemotherapy (NAC) in breast cancer may change the status of biomarker expression, which in turn will affect further management of these patients. In this study we take advantage of a relatively large cohort and aim to study the effect of NAC on biomarker expression and explore the impact of tumor size and lymph node involvement on biomarker status changes. We collected 107 patients with invasive breast cancer who received at least three cycles of NAC. We retrospectively performed and scored the immunohistochemistry (IHC) of ER, PR, HER2 and Ki-67 using both the diagnostic core biopsies before NAC and excisional specimens following NAC. HER2 gene status was assessed by fluorescence in situ hybridization for cases with IHC result of 2+. We demonstrated that there was a significant decrease in expression of PR (P = 0.013) and Ki-67 (P = 0.000) in post-NAC specimens compared to pre-NAC core biopsies. In addition, cases with large tumor size (≥2cm) and cases with lymph node metastasis were more frequently to have biomarker changes. Finally we studied cases with HER2 status changes after NAC treatments in detail and emphasized the nature of tumor heterogeneity.

Tobacco mosaic virus-based protein nanoparticles and nanorods for chemotherapy delivery targeting breast cancer

Drug delivery systems are required for drug targeting to avoid adverse effects associated with chemotherapy treatment regimes. Our approach is focused on the study and development of plant virus-based materials as drug delivery systems; specifically, this work focuses on the tobacco mosaic virus (TMV). Native TMV forms a hollow, high aspect-ratio nanotube measuring 300×18nm with a 4nm-wide central channel. Heat-transformation can be applied to TMV yielding spherical nanoparticles (SNPs) measuring ~50nm in size. While bioconjugate chemistries have been established to modify the TMV rod, such methods have not yet been described for the SNP platform. In this work, we probed the reactivity of SNPs toward bioconjugate reactions targeting lysine, glutamine/aspartic acid, and cysteine residues. We demonstrate functionalization of SNPs using these chemistries yielding efficient payload conjugation. In addition to covalent labeling techniques, we developed encapsulation techniques, where the cargo is loaded into the SNP during heat-transition from rod-to-sphere. Finally, we developed TMV and SNP formulations loaded with the chemotherapeutic doxorubicin, and we demonstrate the application of TMV rods and spheres for chemotherapy delivery targeting breast cancer.