Prescription patterns of granulocyte colony-stimulating factors in patients with breast cancer: A real-world study.

BACKGROUND AND OBJECTIVES: Myelosuppressive chemotherapy is effective for breast cancer but carries a potential risk of febrile neutropenia (FN). Clinical practice guidelines have recommended prophylaxis with granulocyte colony-stimulating factor (G-CSF) to reduce the incidence of FN in patients receiving chemotherapy. We aimed to examine the use of G-CSFs for primary prophylaxis for FN and to see whether it follows the guidelines. In addition, we examined the changes in the use of long-acting and short-acting G-CSFs in patients with breast cancer over the past ten years. METHODS: This was a retrospective observational real-world study. The data were obtained from the clinical research database of three hospitals affiliated with Taipei Medical University. Patients with breast cancer who initiated their first chemotherapy regimen between January 1, 2011, and December 31, 2020, were identified by the ICD codes and their use of filgrastim or pegfilgrastim was identified by the Anatomical Therapeutic Chemical codes. Whether and how G-CSF was prescribed during the study patients' first chemotherapy regimen was examined, and the annual change in the total number of short- and long-acting G-CSFs prescribed to the study patients from 2011 to 2020 was analyzed. RESULTS: Among the 2,444 patients who were prescribed at least one of the examined 15 breast cancer chemotherapy drugs, 1,414 did not use any G-CSFs during their first chemotherapy regimen while 145 used G-CSFs for primary prophylaxis and 185 for treatment. Among the patients receiving high FN risk regimens, only 8.6% used G-CSF for primary prophylaxis. The average (± SD) number of days for short-acting G-CSF use was 2.3 (± 1.5) days with a median of 2 days. In addition, it was found that there was a significant reduction in long-acting G-CSF use (p = 0.03) whereas the changes in short-acting G-CSF use over time were not significant (p = 0.50). CONCLUSIONS: Our study results show that G-CSFs are used for primary prophylaxis in a small percentage of patients with breast cancer and the duration of short-acting G-CSF use is relatively short. Considering the significant clinical and economic impact of FN, it is hoped that the prescription patterns of G-CSFs observed can provide an important reference for future clinical practice and reimbursement policy.

Noggin is required for first pharyngeal arch differentiation in the frog Xenopus tropicalis.

The dorsal ventral axis of vertebrates requires high BMP activity for ventral development and inhibition of BMP activity for dorsal development. Presumptive dorsal regions of the embryo are protected from the ventralizing activity of BMPs by the secretion of BMP antagonists from the mesoderm. Noggin, one such antagonist, binds BMP ligands and prevents them from binding their receptors, however, a unique role for Noggin in amphibian development has remained unclear. Previously, we used zinc-finger nucleases to mutagenize the noggin locus in Xenopus tropicalis. Here, we report on the phenotype of noggin mutant frogs as a result of breeding null mutations to homozygosity. Early homozygous noggin mutant embryos are indistinguishable from wildtype siblings, with normal neural induction and neural tube closure. However, in late tadpole stages mutants present severe ventral craniofacial defects, notably a fusion of Meckel's cartilage to the palatoquadrate cartilage. Consistent with a noggin loss-of-function, mutants show expansions of BMP target gene expression and the mutant phenotype can be rescued with transient BMP inhibition. These results demonstrate that in amphibians, Noggin is dispensable for early embryonic patterning but is critical for cranial skeletogenesis.

Improvement of optical transmittance and electrical properties for the Si quantum dot-embedded ZnO thin film.

A Si quantum dot (QD)-embedded ZnO thin film is successfully fabricated on a p-type Si substrate using a ZnO/Si multilayer structure. Its optical transmittance is largely improved when increasing the annealing temperature, owing to the phase transformation from amorphous to nanocrystalline Si QDs embedded in the ZnO matrix. The sample annealed at 700°C exhibits not only high optical transmittance in the long-wavelength range but also better electrical properties including low resistivity, small turn-on voltage, and high rectification ratio. By using ZnO as the QDs' matrix, the carrier transport is dominated by the multistep tunneling mechanism, the same as in a n-ZnO/p-Si heterojunction diode, which clearly differs from that using the traditional matrix materials. Hence, the carriers transport mainly in the ZnO matrix, not through the Si QDs. The unusual transport mechanism using ZnO as matrix promises the great potential for optoelectronic devices integrating Si QDs.

Optical properties and sub-bandgap formation of nano-crystalline Si quantum dots embedded ZnO thin film.

In this study, we fabricate ZnO thin films with nano-crystalline Si (nc-Si) quantum dots (QDs) using a ZnO/Si multilayer deposition structure and a post-annealing process, and the formation of high crystallinity of Si QDs embedded in the crystalline ZnO matrix is demonstrated. For optical properties, the essential features of ZnO material, high transmission in long-wavelength and high absorption in short-wavelength ranges, are preserved. We observe significantly enhanced light absorption and an unusual photoluminescence emission peak contributed from the nc-Si QDs in the middle-wavelength range. In addition, we confirm the formation of optical sub-bandgap and the obtained value is quite close to the unusual PL emission peak. We show that meaningful sub-bandgap can form in ZnO thin film by embedding nc-Si QDs while maintaining the advantageous properties of ZnO matrix. This newly developed composite material, nc-Si QD embedded ZnO thin films, can be useful for various electro-optical applications.

Defective DNA repair and cell cycle arrest in cells expressing Merkel cell polyomavirus T antigen.

The pathways by which Merkel cell polyomavirus (MCV) infection contributes to the formation of Merkel cell carcinomas are important for understanding the pathogenesis of these cancers. We hypothesized that MCV T antigen suppresses normal responses to ultraviolet radiation (UVR)-induced DNA damage. An MCV-infected cell line (MKL-1) exhibited UVR hypersensitivity, impaired repair of DNA lesions and cell cycle arrest after UVR, as well as reduced levels of the DNA damage recognition protein, XPC. When ectopically expressed in uninfected UISO cells, mutant but not wild-type T antigen resulted in loss of repair of UVR-induced cyclobutane pyrimidine dimers and reductions in XPC, p53 and p21 levels, whereas both wild-type and mutant T antigen inhibited cell cycle arrest after UVR. Similarly, only mutant T antigen in normal fibroblasts inhibited DNA repair and XPC expression, while both mutant and wild-type T antigens produced cell cycle dysregulation. Wild-type T antigen expression produced large T, 57 kT and small T antigens while mutant T antigen was only detectable as a truncated large T antigen protein. Expression of wild-type large T antigen but not small T antigen inhibited the G1 checkpoint in UISO cells, but neither wild-type large T nor small T antigens affected DNA repair, suggesting that large T antigen generates cell cycle defects, and when mutated may also impair DNA repair. These results indicate that T antigen expression by MCV can inhibit key responses to UVR-induced DNA damage and suggest that progressive MCV-mediated abrogation of genomic stability may be involved in Merkel cell carcinogenesis.

Obtusilactone A and (-)-sesamin induce apoptosis in human lung cancer cells by inhibiting mitochondrial Lon protease and activating DNA damage checkpoints.

Several compounds from Cinnamomum kotoense show anticancer activities. However, the detailed mechanisms of most compounds from C. kotoense remain unknown. In this study, we investigated the anticancer activity of obtusilactone A (OA) and (-)-sesamin in lung cancer. Our results show that human Lon is upregulated in non-small-cell lung cancer (NSCLC) cell lines, and downregulation of Lon triggers caspase-3 mediated apoptosis. Through enzyme-based screening, we identified two small-molecule compounds, obtusilactone A (OA) and (-)-sesamin from C. kotoense, as potent Lon protease inhibitors. Obtusilactone A and (-)-sesamin interact with Ser855 and Lys898 residues in the active site of the Lon protease according to molecular docking analysis. Thus, we suggest that cancer cytotoxicity of the compounds is partly due to the inhibitory effects on Lon protease. In addition, the compounds are able to cause DNA double-strand breaks and activate checkpoints. Treatment with OA and (-)-sesamin induced p53-independent DNA damage responses in NSCLC cells, including G(1) /S checkpoint activation and apoptosis, as evidenced by phosphorylation of checkpoint proteins (H2AX, Nbs1, and Chk2), caspase-3 cleavage, and sub-G(1) accumulation. In conclusion, OA and (-)-sesamin act as both inhibitors of human mitochondrial Lon protease and DNA damage agents to activate the DNA damage checkpoints as well induce apoptosis in NSCLC cells. These dual functions open a bright avenue to develop more selective chemotherapy agents to overcome chemoresistance and sensitize cancer cells to other chemotherapeutics.