Two-weekly docetaxel in treatment of advanced breast cancer: A preliminary study

OBJECTIVE

Three-weekly docetaxel causes a high rate of febrile neutropenia, especially in the Asian population. Two-weekly docetaxel has been shown to reduce rate of febrile neutropenia in castrate-resistant prostate cancer patients. We conducted a preliminary study to investigate the safety of two-weekly docetaxel in advanced breast cancer patients.

METHODS

We recruited 10 patients with advanced breast cancer with ECOG (Eastern Cooperative Oncology Group) performance status score of zero to two, who needed chemotherapy in the first or second-line setting to receive two-weekly docetaxel for 8 cycles. The primary endpoint was safety and secondary endpoints were response rate and progression free survival.

RESULTS

The most reported adverse events were haematological (anaemia 100% and neutropenia 90%). The febrile neutropenia rate was 10%. The overall response rate was 20%. The median progression free survival was 5.0 months.

CONCLUSION

Two-weekly docetaxel may be a reasonable alternative treatment regimen for patients with advanced breast cancer in the first or second-line setting. This regimen is yet to be compared with standard 3-weekly schedule in a phase 3 randomised clinical trial.

Reduced matrix metalloproteinase and collagen transcription mediated by the TGF-β/Smad pathway in passaged normal human dermal fibroblasts

BACKGROUND

Transforming growth factor-β (TGF-β) is a major regulator of extracellular matrix (ECM) events, particularly collagen production.

AIM

We explored whether the expression of matrix metalloproteinases (MMPs) and collagen are transcriptionally regulated by the TGF-β and Smad signaling pathways, and the roles played by NF-κB and mitogen-activated protein kinase (MAPK) signaling in normal, aged, human dermal fibroblasts.

METHODS

We quantified mRNA and protein expression using real-time PCR and immunoblotting of proteins from cells in passage 5-15.

RESULTS

The levels of mRNAs encoding TGF-β1, TGF-β3, and TGF-β receptor type I (TGFβ RI) decreased with increasing passage number. The levels of mRNAs encoding TGF-β2, TGFβ RII, and TGFβ RIII increased to passage 10 but decreased by passage 15. The levels of mRNAs encoding Smad-2, -3, -4, and -7 decreased with increasing passage number. The level of mRNA encoding MMP-1 increased with increasing passage number, and the levels of mRNAs encoding MMP-2, TIMP-1, and TIMP-2 increased to passage 10 but decreased by passage 15. The levels of mRNAs encoding collagen types I and II decreased with increasing passage number. At the protein level, NF-κB, IκBα, p38, ERK, Akt, and JNK became increasingly phosphorylated at higher passage numbers.

CONCLUSION

Our results suggest that reductions in the expression levels of MMPs and collagen types I and III in aging human dermal fibroblasts reflect reduced expression of TGF-β/Smad and TGF-β receptors, thus compromising the TGF-β receptor-binding capacity of fibroblasts; the NF-κB and Akt-JNK/MAPK signaling pathways may play active roles in this process.

Using reflectance confocal microscopy to observe in vivo melanolysis after treatment with the picosecond alexandrite laser and Q-switched Nd:YAG laser in melasma

OBJECTIVES

Melasma is an acquired type of hyperpigmentation that is characterized by the appearance of scattered light- to dark-brown macules and patches on the face. Recently, several lasers have been proposed as treatment options for melasma. In particular, the picosecond alexandrite laser is an ideal laser for selective photothermal melanolysis. The aim of our study was to compare the effectiveness in melanolysis of a single treatment of the picosecond alexandrite laser with that of the Q-switched Nd:YAG laser using reflectance confocal microscopy imaging of the melasma lesions.

MATERIALS AND METHODS

We performed a spilt-face study using the picosecond alexandrite laser and Q-switched Nd:YAG laser in eight patients with melasma. Both melasma lesions and surrounding normal skin were examined under reflectance confocal microscopy 1 and 24 hours after treatment. The melanin intensity of each skin layer was investigated.

RESULTS

At baseline, melasma has irregular melanin distribution and a higher melanin density than surrounding normal skin under reflectance confocal microscopy. After a single treatment with either the picosecond alexandrite laser or the Q-switched Nd:YAG laser, both melanin-induced reflectance and melanin index decreased.

CONCLUSION

Our findings suggest that it is feasible to assess the distribution of melanin by reflectance confocal microscopy and observe the melanolysis in melasma lesion after laser treatment. Lasers Surg. Med. 51:423-429, 2019. © 2018 Wiley Periodicals, Inc.

Identification of bacterial guanylate cyclases

The ability of bacteria to use cGMP as a second messenger has been controversial for decades. Recently, nucleotide cyclases from Rhodospirillum centenum, GcyA, and Xanthomonas campestris, GuaX, have been shown to possess guanylate cyclase activities. Enzymatic activities of these guanylate cyclases measured in vitro were low, which makes interpretation of the assays ambiguous. Protein sequence analysis at present is insufficient to distinguish between bacterial adenylate and guanylate cyclases, both of which belong to nucleotide cyclases of type III. We developed a simple method for discriminating between guanylate and adenylate cyclase activities in a physiologically relevant bacterial system. The method relies on the use of a mutant cAMP receptor protein, CRPG , constructed here. While wild-type CRP is activated exclusively by cAMP, CRPG can be activated by either cAMP or cGMP. Using CRP- and CRPG -dependent lacZ expression in two E. coli strains, we verified that R. centenum GcyA and X. campestris GuaX have primarily guanylate cyclase activities. Among two other bacterial nucleotide cyclases tested, one, GuaA from Azospillrillum sp. B510, proved to have guanylate cyclase activity, while the other one, Bradyrhizobium japonicum CyaA, turned out to function as an adenylate cyclase. The results obtained with this reporter system were in excellent agreement with direct measurements of cyclic nucleotides secreted by E. coli expressing nucleotide cyclase genes. The simple genetic screen developed here is expected to facilitate identification of bacterial guanylate cyclases and engineering of guanylate cyclases with desired properties.

Cadaverine is transported into Vibrio vulnificus through its CadB in alkaline environment

The exogenously-added cadaverine is effective in protecting Vibrio vulnificus from methyl viologen (MV)-induced superoxide stress at pH 8.5. Such a protective effect by cadaverine was not observed at pH 7.5. Consistently, the accumulated level of intracellular cadaverine at pH 8.5 is approximately four times as much as that of the control cell at pH 7.5. Cadaverine accumulation is not affected by MV. The protection of V. vulnificus by cadaverine from superoxide stress was abolished when cadB coding for lysine-cadaverine antiporter was interrupted. However, the cadaverine-mediated protection was complemented with cadB DNA. Therefore, CadB of V. vulnificus not only acts as a lysine-cadaverine antiporter at acid pH to neutralize the external medium but also mediates cadaverine uptake at alkaline pH to result in cell protection from superoxide stress.

The virulence of Vibrio vulnificus is affected by the cellular level of superoxide dismutase activity

The virulence of superoxide dismutase (SOD) mutants of Vibrio vulnificus, as tested by intraperitoneal injection into mice, decreases in the order of sodC mutant, sodA mutant, and sodB mutant lacking CuZnSOD, MnSOD, and FeSOD, respectively. The survival of SOD mutants under superoxide stress also decreases in the same order. The virulence of soxR mutant, which is unable to induce MnSOD in response to superoxide, is similar to that of the sodA mutant, as the survival of the soxR mutant under superoxide stress is similar to that of the sodA mutant. Consistently, the lowered survival of the soxR mutant is complemented not only with soxR but also with sodA. Thus, the virulence of V. vulnificus is significantly affected by the cellular level of SOD activity, and an increase in SOD level through MnSOD induction by SoxR under superoxide stress is essential for virulence.

Cadaverine protects Vibrio vulnificus from superoxide stress

An electron paramagnetic resonance (EPR) signal characteristic of the 5,5'-dimethyl-1-pyrroline-N-oxide (DMPO)-OH spin adduct, which is formed from the reaction of DMPO with superoxide radicals generated by xanthine oxidase-mediated reaction, was significantly reduced by the cadaverine or Escherichia coli Mn-containing superoxide dismutase (MnSOD). Likewise, cytochrome c reduction by superoxide was inhibited by cadaverine, and the inhibition level increased in proportion to the level of cadaverine. The cadA mutant of Vibrio vulnificus, which does not produce cadaverine because of the lack of lysine decarboxylase, exhibits less tolerance to superoxide stress in comparison with wild type. The results indicate that cadaverine scavenges superoxide radicals, and protects cells from oxidative stress.

Population genetics of the hypervariable locus D12S391 in Koreans

The hypervariable short tandem repeat (STR) locus D12S391 was investigated in a Korean population and 34 fragments were sequenced to confirm the structure of alleles. From these sequenced fragments an allelic ladder containing 13 sequenced alleles was constructed. From 595 unrelated Koreans, 14 alleles were detected and one variant allele 19.3 was observed. The observed heterozygosity was 0.795 and no deviation from Hardy-Weinberg equilibrium was observed in the Korean population (p = 0.606). The allele frequency distribution in the Korean population was not similar to other racial or ethnic groups except for Egyptians, Yemenis, Japanese and Caucasoids from the Rhine area. No mutations were observed in the 702 meioses from 144 Korean families. This study demonstrates that the STR locus D12S391 is a useful tool for forensic identification and parentage testing.

A Korean population study of the nine STR loci FGA, VWA, D3S1358, D18S51, D21S11, D8S1179, D7S820, D13S317 and D5S818

DNA typing was performed on 379 randomly selected unrelated Koreans using the nine short tandem repeat loci FGA, VWA, D3S1358, D18S51, D21S11, D8S1179, D7S820, D13S317 and D5S818 present in the AmpF/STR Profiler Plus PCR amplification kit. Allele frequencies, heterozygosity, power of discrimination, mean exclusion chance, and polymorphism information content of each locus were calculated by statistical analysis. All nine loci were in Hardy-Weinberg equilibrium. The combined discrimination index and the combined mean exclusion chance in Koreans was 2.31 x 10(-12) and 0.99983, respectively. By evaluation of 297 children from 128 families, 2 mutations were found at the FGA locus and 1 each at the D18S51 and D13S317 loci. This study demonstrates that this multiplex system is a useful and convenient tool for forensic identification and parentage testing in Korea.