Эффективность двухкомпонентного режима индукционной химиотерапии при лечении ВПЧ-позитивного плоскоклеточного рака ротоглотки

Given the favorable prognosis associated with HPV-positive oropharyngeal cancer, cancer care professionals are actively discussing the feasibility of de-escalating treatment strategy for this cohort of patients.The purpose of the study was to improve the treatment outcomes in patients with locally advanced HPV- positive oropharyngeal squamous cell carcinoma by identifying the optimal induction chemotherapy (ICH) regimen, in particular, by using a two-drug ICH.Material and Methods. The study included 27 patients with locally advanced (T3–4N0–1, or T1–4N2–3) P16-positive oropharyngeal squamous cell carcinoma. All patients received 3 cycles of ICT according to the TP (docetaxel + cisplatin) regimen. To assess the effect and toxicity of two-drug ICH, a control group of patients, who received ICH according to the standard three-drug TPF (docetaxel, cisplatin and 5FU) regimen, was formed.Results. In the TP group, complete response (CR) was achieved in 3 (11 %) patients, partial response (PR) in 17 (63 %), stable disease (SD) in 7 (26 %) patients. In the control group: CR 4 (20 %) patients, PR – 13 (60 %), SD – 4 (20 %) patients. The median follow-up time in the TP group was 9 months (range: 2 to 22 months). The 1-year progression-free (PFS) and overall survival (OS) rates were 88.2 % and 100 %, respectively. In the TPF group, the PFS and OS rates were 84.4 % and 100 %, respectively.Conclusion. The results revealed that TP ICH regimen was non-inferior to the standard TPF regimen in the rates of the objective response, 1-year OS and PFS. Учитывая благоприятный прогноз течения заболевания у пациентов с ВПЧ-ассоциированным раком ротоглотки, активно обсуждается вопрос о возможности редукции объема лечения для данной когорты больных. В данной статье представлены промежуточные результаты собственного исследования, направленного на изучение возможности успешного применения двукомпонентного режима ИХТ по схеме ТР.Цель исследования – оценить результаты лечения местнораспространенного ВПЧ-позитивного плоскоклеточного рака ротоглотки путем оптимизации режима индукционной химиотерапии, в частности использования двухкомпонентной схемы.Материалы и методы. С 2021 г. в исследование включено 27 пациентов с местнораспространенным ВПЧ-позитивным плоскоклеточным раком ротоглотки (T3–4N0–1 либо T1–4N2–3), которым на первом этапе комбинированного лечения проводилось 3 курса ИХТ по схеме ТР. Для оценки эффективности и токсичности двухкомпонентной схемы ИХТ сформирована контрольная группа, получающая стандартный режим ИХТ по схеме TPF.Результаты. В настоящий момент проведена оценка объективного ответа для всех больных исследуемой и контрольной групп. Контроль над заболеванием достигнут у 100 % пациентов обеих групп. В исследуемой группе: полный ответ по первичной опухоли и лимфатическим узлам получен у 3 (11 %), частичный ответ – у 17 (63 %), стабилизация – у 7 (26 %) больных. В группе контроля: полный ответ по первичной опухоли и лимфатическим узлам отмечен у 4 (20 %), частичный ответ – у 13 (60 %), стабилизация – у 4 (20 %) пациентов. Медиана времени наблюдения в исследуемой группе составляет 9 мес (от 2 до 22 мес). Показатель 1-годичной ВБП оценен для 15 больных и составил 88,2 %, ОВ – 100 %. Медиана времени наблюдения для группы контроля составляет 12 мес (от 5 до 22 мес), при этом ОВ – 100 %, 1-годичная ВБП (17 пациентов) – 84,4 %.Заключение. Исследовательский двухкомпонентный режим ИХТ продемонстрировал высокие показатели объективного ответа, 1-годичной общей и безрецидивной выживаемости, сопоставимые со стандартной схемой TPF

Rapid sample delivery for megahertz serial crystallography at X-ray FELs

Liquid microjets are a common means of delivering protein crystals to the focus of X-ray free-electron lasers (FELs) for serial femtosecond crystallography measurements. The high X-ray intensity in the focus initiates an explosion of the microjet and sample. With the advent of X-ray FELs with megahertz rates, the typical velocities of these jets must be increased significantly in order to replenish the damaged material in time for the subsequent measurement with the next X-ray pulse. This work reports the results of a megahertz serial diffraction experiment at the FLASH FEL facility using 4.3 nm radiation. The operation of gas-dynamic nozzles that produce liquid microjets with velocities greater than 80 m s-1 was demonstrated. Furthermore, this article provides optical images of X-ray-induced explosions together with Bragg diffraction from protein microcrystals exposed to trains of X-ray pulses repeating at rates of up to 4.5 MHz. The results indicate the feasibility for megahertz serial crystallography measurements with hard X-rays and give guidance for the design of such experiments

Catalytic cleavage of HEAT and subsequent covalent binding of the tetralone moiety by the SARS-CoV-2 main protease

Here we present the crystal structure of SARS-CoV-2 main protease (Mpro) covalently bound to 2-methyl-1-tetralone. This complex was obtained by co-crystallization of Mpro with HEAT (2-(((4-hydroxyphenethyl)amino)methyl)-3,4-dihydronaphthalen-1(2H)-one) in the framework of a large X-ray crystallographic screening project of Mpro against a drug repurposing library, consisting of 5632 approved drugs or compounds in clinical phase trials. Further investigations showed that HEAT is cleaved by Mpro in an E1cB-like reaction mechanism into 2-methylene-1-tetralone and tyramine. The catalytic Cys145 subsequently binds covalently in a Michael addition to the methylene carbon atom of 2-methylene-1-tetralone. According to this postulated model HEAT is acting in a pro-drug-like fashion. It is metabolized by Mpro, followed by covalent binding of one metabolite to the active site. The structure of the covalent adduct elucidated in this study opens up a new path for developing non-peptidic inhibitors

Segmented flow generator for serial crystallography at the European X-ray free electron laser

Serial femtosecond crystallography (SFX) with X-ray free electron lasers (XFELs) allows structure determination of membrane proteins and time-resolved crystallography. Common liquid sample delivery continuously jets the protein crystal suspension into the path of the XFEL, wasting a vast amount of sample due to the pulsed nature of all current XFEL sources. The European XFEL (EuXFEL) delivers femtosecond (fs) X-ray pulses in trains spaced 100 ms apart whereas pulses within trains are currently separated by 889 ns. Therefore, continuous sample delivery via fast jets wastes >99% of sample. Here, we introduce a microfluidic device delivering crystal laden droplets segmented with an immiscible oil reducing sample waste and demonstrate droplet injection at the EuXFEL compatible with high pressure liquid delivery of an SFX experiment. While achieving ~60% reduction in sample waste, we determine the structure of the enzyme 3-deoxy-D-manno-octulosonate-8-phosphate synthase from microcrystals delivered in droplets revealing distinct structural features not previously reported

X-ray screening identifies active site and allosteric inhibitors of SARS-CoV-2 main protease

The coronavirus disease (COVID-19) caused by SARS-CoV-2 is creating tremendous human suffering. To date, no effective drug is available to directly treat the disease. In a search for a drug against COVID-19, we have performed a high-throughput X-ray crystallographic screen of two repurposing drug libraries against the SARS-CoV-2 main protease (M^(pro)), which is essential for viral replication. In contrast to commonly applied X-ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three-dimensional protein structures, we identified 37 compounds that bind to M^(pro). In subsequent cell-based viral reduction assays, one peptidomimetic and six non-peptidic compounds showed antiviral activity at non-toxic concentrations. We identified two allosteric binding sites representing attractive targets for drug development against SARS-CoV-2

Massive X-ray screening reveals two allosteric drug binding sites of SARS-CoV-2 main protease

The coronavirus disease (COVID-19) caused by SARS-CoV-2 is creating tremendous health problems and economical challenges for mankind. To date, no effective drug is available to directly treat the disease and prevent virus spreading. In a search for a drug against COVID-19, we have performed a massive X-ray crystallographic screen of repurposing drug libraries containing 5953 individual compounds against the SARS-CoV-2 main protease (Mpro), which is a potent drug target as it is essential for the virus replication. In contrast to commonly applied X-ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three-dimensional protein structures, we identified 37 compounds binding to Mpro. In subsequent cell-based viral reduction assays, one peptidomimetic and five non-peptidic compounds showed antiviral activity at non-toxic concentrations. Interestingly, two compounds bind outside the active site to the native dimer interface in close proximity to the S1 binding pocket. Another compound binds in a cleft between the catalytic and dimerization domain of Mpro. Neither binding site is related to the enzymatic active site and both represent attractive targets for drug development against SARS-CoV-2. This X-ray screening approach thus has the potential to help deliver an approved drug on an accelerated time-scale for this and future pandemics

X ray screening identifies active site and allosteric inhibitors of SARS CoV 2 main protease

The coronavirus disease COVID 19 caused by SARS CoV 2 is creating tremendous human suffering. To date, no effective drug is available to directly treat the disease. In a search for a drug against COVID 19, we have performed a high throughput x ray crystallographic screen of two repurposing drug libraries against the SARS CoV 2 main protease Mpro , which is essential for viral replication. In contrast to commonly applied x ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three dimensional protein structures, we identified 37 compounds that bind to Mpro. In subsequent cell based viral reduction assays, one peptidomimetic and six nonpeptidic compounds showed antiviral activity at nontoxic concentrations. We identified two allosteric binding sites representing attractive targets for drug development against SARS CoV

Basic principles of managing radiation and drug induced mucositis and dermatitis for oropharyngeal squamouscell carcinoma

The work illustrates main issues of the radial treatment acceptability with the modification of patients with the squamous cell carcinoma of the oropharyngeal area. The spectrum of side effects is given and key issues of the accompanying therapy are concerned. Separately are given approaches to the treatment of patients with radial mucositis and dermatitis

Prevalence, clinical significance and possible correction of taste and smell abnormalities in patients with oncological diseases

The article discusses main issues relating to abnormal taste and smell, which may an oncologist come across in the treatment practice. It also describes mechanisms of dysgeusia and disosmia development, as well as their relationship with nutritional deficiency. Authors review approaches to assess sensory disorders before treatment, at all the stages and after radiation therapy and chemotherapy. They present the world experience in managing patients with the abnormalities and their possible correction

Nutritional support as an obligatory component of accompanying therapy for head and neck tumors during radiotherapy and chemoradiotherapy

The article considers supportive therapy in patients with head and neck tumors during radiotherapy and chemoradiotherapy. Special attention is given to nutritional support on every stage of patient care. The main methods of evaluation of nutritional status and risks are presented, as well as principles of clinical nutrition selection