1
|
Koppiker CB, Kelkar DA, Kulkarni M, Kadu S, Pai M, Dhar U, Deshmukh C, Varghese B, Zamre V, Jumle N, Gangurde N, Joshi A, Unde R, Banale R, Namewar N, Vaid P, Busheri L, Thomas G, Nare S, Pereira J, Badve S. Impact of oncoplasty in increasing breast conservation rates Post neo-adjuvant chemotherapy. Front Oncol 2023; 13:1176609. [PMID: 37746279 PMCID: PMC10514208 DOI: 10.3389/fonc.2023.1176609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 07/19/2023] [Indexed: 09/26/2023] Open
Abstract
Introduction The essential goal of neoadjuvant chemotherapy (NACT) is to downstage the primary tumor making it amenable for breast conservation surgery (BCS). However, since the safety of this surgery is paramount, post-NACT breast conservation rates remain low. As per the recommendation of the 2018 Early Breast Cancer Trialists' Collaborative Group (EBCTCG) overview of long-term post-NACT follow-up, we have devised a protocol for imaging, localization, rad-path analysis, and documentation of radiotherapy techniques to ensure the safety of post-NACT breast conservation. Methods This is a retrospective cohort of 180 breast cancer patients who received NACT and were operated on by a single surgical oncologist from 2015 to 2020. After selection based on published guidelines, patients were treated with neoadjuvant systemic (chemo or hormone) therapy. In cases where primary tumors responded and reduced to 1-2 cm in size mid-NACT, the residual tumors were localized by clips under ultrasound guidance and calcification was wire localized. All patients were treated using appropriate surgical and oncoplastic techniques where indicated. Negative margins were ensured by intra-operative rad-path analysis. Adjuvant chemotherapy and radiotherapy were given as per protocol. Results In 81 cases that required mastectomy at presentation, we were able to achieve a 72.8% post-NACT BCS rate with the help of oncoplasty. Overall, 142 of 180 (80%) patients were treated with breast conserving surgery of which 80% (121 of 142) were oncoplasty. Margins were assessed on intra-operative frozen and re-excised in the same setting. No positive margins were reported in final histopath of 142 breast conservation procedures. Post-operative complication rates after breast conservation in the first year were at 17% (24 of 142 including two major complications). Patient reported outcomes were satisfactory with increased satisfaction for breast conservation compared with immediate breast reconstruction. Discussion Employing oncoplastic breast surgery (OBS) techniques following stringent protocols for accurate localization of the residual tumor, intra-operative rad-path analysis, and adjuvant treatments, we show successful breast conservation in 72.8% of our mastectomy-qualified patients after downstaging by NACT. We also report satisfactory outcomes for post-NACT surgery, patient-reported satisfaction, and survival.
Collapse
Affiliation(s)
- Chaitanyanand B. Koppiker
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
- Department of Onco-Sciences, Jehangir Hospital, Pune, India
- International School of Oncoplasty, Pune, India
- Orchids Breast Health Centre, A Prashanti Cancer Care Mission (PCCM) Initiative, Pune, India
| | - Devaki A. Kelkar
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Madhura Kulkarni
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Shweta Kadu
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Mugdha Pai
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Upendra Dhar
- Department of Onco-Sciences, Jehangir Hospital, Pune, India
- Orchids Breast Health Centre, A Prashanti Cancer Care Mission (PCCM) Initiative, Pune, India
| | - Chetan Deshmukh
- Department of Onco-Sciences, Jehangir Hospital, Pune, India
- Orchids Breast Health Centre, A Prashanti Cancer Care Mission (PCCM) Initiative, Pune, India
| | - Beenu Varghese
- Department of Onco-Sciences, Jehangir Hospital, Pune, India
- Orchids Breast Health Centre, A Prashanti Cancer Care Mission (PCCM) Initiative, Pune, India
| | | | - Nutan Jumle
- Department of Onco-Sciences, Jehangir Hospital, Pune, India
| | - Nutan Gangurde
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Anjali Joshi
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Rohini Unde
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Rituja Banale
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Namrata Namewar
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Pooja Vaid
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
- Ashoka University – Department of Biology, Ashoka University, Haryana, India
| | | | - George Thomas
- Orchids Breast Health Centre, A Prashanti Cancer Care Mission (PCCM) Initiative, Pune, India
| | - Smeeta Nare
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and Indian Institute of Science Education and Research (IISER), Pune, India
| | - Jerome Pereira
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Sunil Badve
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, United States
| |
Collapse
|
2
|
Koppiker C, Joshi S, Mishra R, Kelkar DA, Chigurupati P, Joshi A, John J, Kadu S, Bagdia A, Thakkar D, Deshmukh C, Allampati H, Sharan G, Dhar U, Nare S, Nagarkar S, Busheri L, Varghese B, Pai M. Therapeutic mammoplasty: a "wise" oncoplastic choice-lessons from the largest single-center cohort from Asia. Front Oncol 2023; 13:1131951. [PMID: 37124516 PMCID: PMC10141318 DOI: 10.3389/fonc.2023.1131951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 03/06/2023] [Indexed: 05/02/2023] Open
Abstract
Introduction The majority of breast cancer patients from India usually present with advanced disease, limiting the scope of breast conservation surgery. Therapeutic mammoplasty (TM), an oncoplastic technique that permits larger excisions, is quite promising in such a scenario and well suited to breast cancer in medium-to-large-sized breasts with ptosis and in some cases of large or multifocal/multicentric tumors. Here, we describe our TM cohort of 205 (194 malignant and 11 benign) patients from 2012 to 2019 treated at a single surgeon center in India, the largest Asian dataset for TM. Methods All patients underwent treatment after careful discussions by a multidisciplinary tumor board and patient counseling. We report the clinicopathological profiles and surgical, oncological, cosmetic, and patient-related outcomes with different TM procedures. Results The median age of breast cancer patients was 49 years; that of benign disease patients was 41 years. The breast cancer cohort underwent simple (n = 84), complex (n = 71), or extreme (n = 44) TM surgeries. All resection margins were analyzed through intra-operative frozen-section assessment with stringent rad-path analysis protocols. The margin positivity rate was found to be 1.4%. A majority of the cohort was observed to have pT1-pT2 tumors, and the median resection volume was 180 cc. Low post-operative complication rates and good-to-excellent cosmetic scores were observed. The median follow-up was 39 months. We observed 2.07% local and 5.7% distal recurrences, and disease-specific mortality was 3.1%. At median follow-up, the overall survival was observed to be 95.9%, and disease-free survival was found to be 92.2%. The patient-reported outcome measures (PROMs) showed good-to-excellent scores for all types of TMs across BREAST-Q domains. Conclusion We conclude that in India, a country where women present with large and locally advanced tumors, TM safely expands the indications for breast conservation surgery. Our results show oncological and cosmetic outcomes at acceptable levels. Most importantly, PROM scores suggest improved overall wellbeing and better satisfaction with the quality of life. For patients with macromastia, this technique not only focuses on cancer but also improves self-image and reduces associated physical discomfort often overlooked by women in the Indian setting. The popularization of this procedure will enable Indian patients with breast cancer to receive the benefits of breast conservation.
Collapse
Affiliation(s)
- Chaitanyanand Koppiker
- Orchids Breast Health Centre, Prashanti Cancer Care Mission, Pune, India
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
- International School of Oncoplastic Surgery, Pune, India
- Jehangir Hospital, Pune, India
- *Correspondence: Chaitanyanand Koppiker,
| | - Sneha Joshi
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
| | - Rupa Mishra
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
| | - Devaki A. Kelkar
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
| | | | - Anjali Joshi
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
| | - Jisha John
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
| | - Shweta Kadu
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
| | | | - Deepti Thakkar
- International School of Oncoplastic Surgery, Pune, India
| | - Chetan Deshmukh
- Orchids Breast Health Centre, Prashanti Cancer Care Mission, Pune, India
| | | | - Gautam Sharan
- Department of Radiation Oncology, Inlaks and Budhrani Hospital, Pune, India
| | - Upendra Dhar
- Orchids Breast Health Centre, Prashanti Cancer Care Mission, Pune, India
- Jehangir Hospital, Pune, India
| | - Smeeta Nare
- Orchids Breast Health Centre, Prashanti Cancer Care Mission, Pune, India
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
| | - Sanket Nagarkar
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
| | - Laleh Busheri
- Orchids Breast Health Centre, Prashanti Cancer Care Mission, Pune, India
| | - Beenu Varghese
- Orchids Breast Health Centre, Prashanti Cancer Care Mission, Pune, India
| | - Mugdha Pai
- Orchids Breast Health Centre, Prashanti Cancer Care Mission, Pune, India
- Centre for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER), Pune and Prashanti Cancer Care Mission (PCCM), Pune, India
| |
Collapse
|
3
|
Joshi S, Mishra R, Kulkarni M, Kelkar DA, Harikrishnan K, Vaid P, V G, John J, Tamhane S, Deshpande A, Badve S, Chintamani, Mehrotra R, Shashidhara LS, Kothari A, Koppiker C. Proceedings of the 3rd Indian Cancer Genome Atlas Conference 2022: Biobanking to Omics: Collecting the Global Experience. JCO Glob Oncol 2023; 9:e2200176. [PMID: 36657087 PMCID: PMC10166449 DOI: 10.1200/go.22.00176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
On January 13th and 14th 2022, the Center for Translational Cancer Research organized the virtual third Indian Cancer Genome Atlas (ICGA) Conference 2022 "Biobanking to Omics - Collecting the Global Experience." This conference was planned as the steppingstone to help ICGA understand the road ahead and the probable roadblocks in its preparatory phase as ICGA begins to streamline the tumor tissue biobanking and multi-omics efforts in the Indian subcontinent. The first day of the conference was dedicated to updates on the current status of ICGA, the future prospect, and the global understanding of multi-omics efforts. The key highlights included two keynote speeches by Dr Wui Jin Koh, Senior Vice President and Chief Medical Office, National Comprehensive Cancer Network, and by Dr Christina Curtis, Associate Professor, Stanford University School of Medicine. The first day ended with an intriguing panel discussion on "ICGA updates and Future Steps." The second day focused on biobanking practices across the globe and several aspects of biobank setup such as infrastructure, maintenance, quality control, patient consent, and lessons learned from established biobanking setups. The talk by Rosita Kammler, Head, Translational Research Coordination, International Breast Cancer Study Group, Switzerland, and Ruhul Amin, Director, Bangladesh Medical Research Council were the key highlights. The second day also ended with an engaging panel discussion on "Tumor tissue biobanking - national and international perspectives." Overall, the conference was well received and had good attendance from national and international students, researchers, and faculty from academia as well as industry.
Collapse
Affiliation(s)
- Sneha Joshi
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,BreastGlobal Network.,Prashanti Cancer Care Mission, Pune, India
| | - Rupa Mishra
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,BreastGlobal Network.,Prashanti Cancer Care Mission, Pune, India
| | - Madhura Kulkarni
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,Prashanti Cancer Care Mission, Pune, India.,Indian Cancer Genome Atlas
| | - Devaki A Kelkar
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,Prashanti Cancer Care Mission, Pune, India
| | | | - Pooja Vaid
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,Department of Biological Sciences, Ashoka University, Sonipat, New Delhi, India
| | - Gomathi V
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,Department of Biological Sciences, Ashoka University, Sonipat, New Delhi, India
| | - Jisha John
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,Prashanti Cancer Care Mission, Pune, India
| | - Siddhi Tamhane
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,Prashanti Cancer Care Mission, Pune, India
| | - Anand Deshpande
- Indian Cancer Genome Atlas.,Persistent Systems Ltd, Pune, India
| | - Sunil Badve
- Indian Cancer Genome Atlas.,Department of Pharmacology and Chemical Biology Emory University School of Medicine, Atlanta, GA
| | - Chintamani
- BreastGlobal Network.,Indian Cancer Genome Atlas.,Department of Surgery, Safdarjung Hospital, New Delhi, India
| | - Ravi Mehrotra
- Indian Cancer Genome Atlas.,Rollins Institute of Public Health, Emory University, Atlanta, GA
| | - L S Shashidhara
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,Indian Cancer Genome Atlas.,Department of Biological Sciences, Ashoka University, Sonipat, New Delhi, India
| | - Ashutosh Kothari
- BreastGlobal Network.,Indian Cancer Genome Atlas.,Guy's & St Thomas NHS Trust, London, United Kingdom
| | - Chaitanyanand Koppiker
- Center for Translational Cancer Research: A Joint Initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM) Pune, India.,BreastGlobal Network.,Prashanti Cancer Care Mission, Pune, India.,Indian Cancer Genome Atlas
| |
Collapse
|
4
|
Vaid PM, Puntambekar AK, Jumle NS, Banale RA, Ansari D, Reddy RR, Unde RR, Namewar NP, Kelkar DA, Shashidhara LS, Koppiker CB, Kulkarni MD. Evaluation of tumor-infiltrating lymphocytes (TILs) in molecular subtypes of an Indian cohort of breast cancer patients. Diagn Pathol 2022; 17:91. [PMID: 36411483 PMCID: PMC9677664 DOI: 10.1186/s13000-022-01271-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/21/2022] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES Evaluation of tumor-infiltrating lymphocytes (TILs) distribution in an Indian cohort of breast cancer patients for its prognostic significance. METHODS A retrospective cohort of breast cancer patients from a single onco-surgeon's breast cancer clinic with a uniform treatment strategy was evaluated for TILs. Tumor sections were H&E stained and scored for the spatial distribution and percent stromal TILs infiltration by a certified pathologist. The scores were analysed for association with treatment response and survival outcomes across molecular subtypes. RESULTS Total 229 breast cancer tumors were evaluated. Within spatial distribution categories, intra-tumoral TILs were observed to be associated with complete pathological response and lower recurrence frequency for the entire cohort. Subtype-wise analysis of stromal TILs (sTILs) re-enforced significantly higher infiltration in TNBC compared to HER2-positive and ER-positive tumors. A favourable association of higher stromal infiltration was observed with treatment response and disease outcomes, specifically in TNBC. CONCLUSION Intra-tumoral TILs showed a higher proportion with favourable association with better patient outcomes in an Indian cohort, unlike western cohorts where both stromal and intra-tumoral TILs show similar association with prognosis. With further validation, TILs can be developed as a cost-effective surrogate marker for treatment response, especially in a low-resource setting such as India.
Collapse
Affiliation(s)
- Pooja M. Vaid
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.449178.70000 0004 5894 7096Department of Biological Sciences, Ashoka University, Sonipat, India
| | | | - Nutan S. Jumle
- grid.414967.90000 0004 1804 743XDepartment of Pathology, Jehangir Hospital, Pune, India
| | - Rituja A. Banale
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.506045.20000 0004 4911 4105Prashanti Cancer Care Mission, Pune, Maharashtra India
| | - Danish Ansari
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.506045.20000 0004 4911 4105Prashanti Cancer Care Mission, Pune, Maharashtra India
| | - Ruhi R. Reddy
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.506045.20000 0004 4911 4105Prashanti Cancer Care Mission, Pune, Maharashtra India
| | - Rohini R. Unde
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.506045.20000 0004 4911 4105Prashanti Cancer Care Mission, Pune, Maharashtra India
| | - Namrata P. Namewar
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.506045.20000 0004 4911 4105Prashanti Cancer Care Mission, Pune, Maharashtra India
| | - Devaki A. Kelkar
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.506045.20000 0004 4911 4105Prashanti Cancer Care Mission, Pune, Maharashtra India
| | - L. S. Shashidhara
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.449178.70000 0004 5894 7096Department of Biological Sciences, Ashoka University, Sonipat, India ,grid.417959.70000 0004 1764 2413Indian Institute of Science Education and Research, Pune, India
| | - Chaitanyanand B. Koppiker
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.506045.20000 0004 4911 4105Prashanti Cancer Care Mission, Pune, Maharashtra India
| | - Madhura D. Kulkarni
- grid.417959.70000 0004 1764 2413Centre for Translational Cancer Research: a joint initiative of Indian Institute of Science Education and Research (IISER) Pune and Prashanti Cancer Care Mission (PCCM), Pune, India ,grid.506045.20000 0004 4911 4105Prashanti Cancer Care Mission, Pune, Maharashtra India
| |
Collapse
|
5
|
Busheri L, Nare S, Banale R, Bapat A, Nagarkar M, Vetale D, Joseph R, Suryawanshi S, Alhat R, Thomas G, Navgire R, Ansari D, Unde R, Shaikh S, Gangurde N, Dixit S, Varghese B, Deshmukh C, Kelkar DA, Kulkarni M, Koppiker CB. Cancer Patient Management during COVID-19 Pandemic: An Audit of a Single-Surgeon Unit in a COVID-Hotspot. South Asian J Cancer 2021; 10:39-41. [PMID: 34430517 PMCID: PMC8380147 DOI: 10.1055/s-0041-1731578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The report evaluates the effect of coronavirus disease (COVID-19) pandemic on breast cancer treatment and management at a single-surgeon cancer care unit in one of the hotspots of COVID-19 in India. In response to the pandemic, the adjustments were made in the clinical practice to accommodate social distancing. Patient consultations were done over phone call or in-clinic visit with prior appointment to reduce the risk of exposure to COVID-19. Total number of patients that were treated at the clinic and the essential surgeries performed during the pandemic phases are summarized in the report. The methodology adopted here for care and management of the cancer patients can serve as a guiding principle for cancer care units in the country.
Collapse
Affiliation(s)
- Laleh Busheri
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Smeeta Nare
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Rituja Banale
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Ashwini Bapat
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Moushumi Nagarkar
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Deepali Vetale
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Rebecca Joseph
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Swapnil Suryawanshi
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Rashmi Alhat
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - George Thomas
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Ruth Navgire
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Danish Ansari
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Rohini Unde
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Shahin Shaikh
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Nutan Gangurde
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Santosh Dixit
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India.,Center for Translational Cancer Research, A Joint Initiative between IISER Pune and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Beenu Varghese
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Chetan Deshmukh
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Devaki A Kelkar
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India.,Center for Translational Cancer Research, A Joint Initiative between IISER Pune and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Madhura Kulkarni
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India.,Center for Translational Cancer Research, A Joint Initiative between IISER Pune and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| | - Chaitanyanand B Koppiker
- Orchid Breast Health Clinic and Prashanti Cancer Care Mission, Pune, Maharashtra, India.,Center for Translational Cancer Research, A Joint Initiative between IISER Pune and Prashanti Cancer Care Mission, Pune, Maharashtra, India
| |
Collapse
|
6
|
Busheri L, Dixit S, Nare S, Alhat R, Thomas G, Jagtap M, Navgire R, Shinde P, Banale R, Unde R, Reddy R, Shaikh S, Konnur A, Namewar N, Bapat A, Patil A, Johari R, Kushwaha R, Kumari W, Varghese B, Deshpande P, Deshmukh C, Kelkar DA, Shashidhara LS, Koppiker CB, Kulkarni M. Breast cancer biobank from a single institutional cohort in an urban setting in india: Tumor characteristics and survival outcomes. Cancer Treat Res Commun 2021; 28:100409. [PMID: 34098400 DOI: 10.1016/j.ctarc.2021.100409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/20/2021] [Accepted: 05/25/2021] [Indexed: 12/24/2022]
Abstract
BACKGROUND A breast cancer biobank with retrospectively collected patient data and FFPE tissue samples was established in 2018 at Prashanti Cancer Care Mission, Pune, India. It runs a cancer care clinic with support from a single surgeon's breast cancer practice. The clinical data and tissue sample collection is undertaken with appropriate patient consent following ethical approval and guidelines. METHODS The biobank holds clinical history, diagnostic reports, treatment and follow-up information along with FFPE tumor tissue specimens, adjacent normal and, in few cases, contralateral normal breast tissue. Detailed family history and germline mutational profiles of eligible and consenting patients and their relatives are also deposited in the biobank. RESULTS Here, we report the first audit of the biobank. A total number of 994 patients with breast disease have deposited consented clinical records in the biobank. The majority of the records (80%, n = 799) are of patients with infiltrating ductal carcinoma (IDC). Of 799 IDC patients, 434 (55%) have deposited tumor tissue in the biobank with consent. In addition, germline mutation profiles of 84 patients and their family members are deposited. Follow-up information is available for 85% of the 434 IDC patients with an average follow-up of 3 years. CONCLUSION The biobank has aided the initiation of translational research at our center in collaboration with eminent institutes like IISER Pune and SJRI Bangalore to evaluate profiles of breast cancer in an Indian cohort. The biobank will be a valuable resource to the breast cancer research community, especially to understand South Asian profiles of breast cancer.
Collapse
Affiliation(s)
| | - Santosh Dixit
- Prashanti Cancer Care Mission, Pune; Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and IISER Pune
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Ankita Patil
- Prashanti Cancer Care Mission, Pune; Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and IISER Pune
| | | | - Roli Kushwaha
- Prashanti Cancer Care Mission, Pune; Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and IISER Pune
| | | | | | | | | | - Devaki A Kelkar
- Prashanti Cancer Care Mission, Pune; Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and IISER Pune
| | - L S Shashidhara
- Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and IISER Pune; Ashoka University, Sonipat, Delhi
| | - Chaitanyanand B Koppiker
- Prashanti Cancer Care Mission, Pune; Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and IISER Pune
| | - Madhura Kulkarni
- Prashanti Cancer Care Mission, Pune; Center for Translational Cancer Research, a Joint venture between Prashanti Cancer Care Mission and IISER Pune.
| |
Collapse
|
7
|
Kulkarni A, Kelkar DA, Parikh N, Shashidhara LS, Koppiker CB, Kulkarni M. Meta-Analysis of Prevalence of Triple-Negative Breast Cancer and Its Clinical Features at Incidence in Indian Patients With Breast Cancer. JCO Glob Oncol 2020; 6:1052-1062. [PMID: 32639876 PMCID: PMC7392736 DOI: 10.1200/go.20.00054] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2020] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Breast cancer is the most common cancer in women in India, with higher incidence rates of aggressive subtypes, such as triple-negative breast cancer (TNBC). METHODS A systematic review was performed to compute pooled prevalence rates of TNBC among patients with breast cancer, and clinical features at presentation were systematically compared with non-TNBC in an Indian cohort of 20,000 patients. RESULTS Combined prevalence of TNBC among patients with breast cancer was found to be on the higher side (27%; 95% CI, 24% to 31%). We found that the estrogen receptor (ER) expression cutoff used to determine ER positivity had an influence on the pooled prevalence and ranged from 30% (ER/progesterone receptor [PR] cut ff at 1%) to 24% (ER/PR cutoff at 10%). Odds for TNBC to present in the younger age-group were significantly higher (pooled odds ratio [OR], 1.35; 95% CI, 1.08 to 1.69), with a significantly younger mean age of incidence (weighted mean difference, -2.75; 95% CI, -3.59 to -1.92). TNBC showed a significantly higher odds of presenting with high grade (pooled OR, 2.57; 95% CI, 2.12 to 3.12) and lymph node positivity (pooled OR, 1.39; 95% CI, 1.21 to 1.60) than non-TNBC. CONCLUSION Systematic review and meta-analysis of 34 studies revealed a high degree of heterogeneity in prevalence of TNBC within Indian patients with breast cancer, yet pooled prevalence of TNBC is high in India. High proportions of patients with TNBC present with aggressive features, such as high grade and lymph node positivity, compared with patients without TNBC. We emphasize the need for standardized methods for accurate diagnosis in countries like India.
Collapse
Affiliation(s)
- Apurv Kulkarni
- Indian Institute of Science Education and Research, Pune, India
| | - Devaki A. Kelkar
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research: A Joint Initiative of Prashanti Cancer Care Mission and Indian Institute of Science Education and Research, Pune, India
| | - Nidhi Parikh
- Indian Institute of Science Education and Research, Pune, India
| | - Lingadahalli S. Shashidhara
- Indian Institute of Science Education and Research, Pune, India
- Center for Translational Cancer Research: A Joint Initiative of Prashanti Cancer Care Mission and Indian Institute of Science Education and Research, Pune, India
| | - Chaitanyanand B. Koppiker
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research: A Joint Initiative of Prashanti Cancer Care Mission and Indian Institute of Science Education and Research, Pune, India
| | - Madhura Kulkarni
- Prashanti Cancer Care Mission, Pune, India
- Center for Translational Cancer Research: A Joint Initiative of Prashanti Cancer Care Mission and Indian Institute of Science Education and Research, Pune, India
| |
Collapse
|
8
|
Kelkar DA, Khushoo A, Yang Z, Skach WR. Kinetic analysis of ribosome-bound fluorescent proteins reveals an early, stable, cotranslational folding intermediate. J Biol Chem 2011; 287:2568-78. [PMID: 22128180 DOI: 10.1074/jbc.m111.318766] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Protein folding in cells reflects a delicate interplay between biophysical properties of the nascent polypeptide, the vectorial nature and rate of translation, molecular crowding, and cellular biosynthetic machinery. To better understand how this complex environment affects de novo folding pathways as they occur in the cell, we expressed β-barrel fluorescent proteins derived from GFP and RFP in an in vitro system that allows direct analysis of cotranslational folding intermediates. Quantitative analysis of ribosome-bound eCFP and mCherry fusion proteins revealed that productive folding exhibits a sharp threshold as the length of polypeptide from the C terminus to the ribosome peptidyltransferase center is increased. Fluorescence spectroscopy, urea denaturation, and limited protease digestion confirmed that sequestration of only 10-15 C-terminal residues within the ribosome exit tunnel effectively prevents stable barrel formation, whereas folding occurs unimpeded when the C terminus is extended beyond the ribosome exit site. Nascent FPs with 10 of the 11 β-strands outside the ribosome exit tunnel acquire a non-native conformation that is remarkably stable in diverse environments. Upon ribosome release, these structural intermediates fold efficiently with kinetics that are unaffected by the cytosolic crowding or cellular chaperones. Our results indicate that during synthesis, fluorescent protein folding is initiated cotranslationally via rapid formation of a highly stable, on-pathway structural intermediate and that the rate-limiting step of folding involves autonomous incorporation of the 11th β-strand into the mature barrel structure.
Collapse
Affiliation(s)
- Devaki A Kelkar
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
| | | | | | | |
Collapse
|
9
|
Kelkar DA, Chaudhuri A, Haldar S, Chattopadhyay A. Exploring tryptophan dynamics in acid-induced molten globule state of bovine α-lactalbumin: a wavelength-selective fluorescence approach. Eur Biophys J 2010; 39:1453-63. [PMID: 20372885 DOI: 10.1007/s00249-010-0603-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 03/01/2010] [Accepted: 03/23/2010] [Indexed: 10/19/2022]
|
10
|
Kelkar DA, Chattopadhyay A. The gramicidin ion channel: A model membrane protein. Biochimica et Biophysica Acta (BBA) - Biomembranes 2007; 1768:2011-25. [PMID: 17572379 DOI: 10.1016/j.bbamem.2007.05.011] [Citation(s) in RCA: 260] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2006] [Revised: 05/09/2007] [Accepted: 05/10/2007] [Indexed: 02/07/2023]
Abstract
The linear peptide gramicidin forms prototypical ion channels specific for monovalent cations and has been extensively used to study the organization, dynamics and function of membrane-spanning channels. In recent times, the availability of crystal structures of complex ion channels has challenged the role of gramicidin as a model membrane protein and ion channel. This review focuses on the suitability of gramicidin as a model membrane protein in general, and the information gained from gramicidin to understand lipid-protein interactions in particular. Special emphasis is given to the role and orientation of tryptophan residues in channel structure and function and recent spectroscopic approaches that have highlighted the organization and dynamics of the channel in membrane and membrane-mimetic media.
Collapse
Affiliation(s)
- Devaki A Kelkar
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | | |
Collapse
|
11
|
Kelkar DA, Chattopadhyay A. Modulation of gramicidin channel conformation and organization by hydrophobic mismatch in saturated phosphatidylcholine bilayers. Biochim Biophys Acta 2007; 1768:1103-13. [PMID: 17321493 DOI: 10.1016/j.bbamem.2007.01.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Revised: 01/18/2007] [Accepted: 01/22/2007] [Indexed: 11/25/2022]
Abstract
The matching of hydrophobic lengths of integral membrane proteins and the surrounding lipid bilayer is an important factor that influences both structure and function of integral membrane proteins. The ion channel gramicidin is known to be uniquely sensitive to membrane properties such as bilayer thickness and membrane mechanical properties. The functionally important carboxy terminal tryptophan residues of gramicidin display conformation-dependent fluorescence which can be used to monitor gramicidin conformations in membranes [S.S. Rawat, D.A. Kelkar, A. Chattopadhyay, Monitoring gramicidin conformations in membranes: a fluorescence approach, Biophys. J. 87 (2004) 831-843]. We have examined the effect of hydrophobic mismatch on the conformation and organization of gramicidin in saturated phosphatidylcholine bilayers of varying thickness utilizing the intrinsic conformation-dependent tryptophan fluorescence. Our results utilizing steady state and time-resolved fluorescence spectroscopic approaches, in combination with circular dichroism spectroscopy, show that gramicidin remains predominantly in the channel conformation and gramicidin tryptophans are at the membrane interfacial region over a range of mismatch conditions. Interestingly, gramicidin conformation shifts toward non-channel conformations in extremely thick gel phase membranes although it is not excluded from the membrane. In addition, experiments utilizing self quenching of tryptophan fluorescence indicate peptide aggregation in thicker gel phase membranes.
Collapse
Affiliation(s)
- Devaki A Kelkar
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | | |
Collapse
|
12
|
Abstract
Spectrin is the major constituent protein of the erythrocyte cytoskeleton which forms a filamentous network on the cytoplasmic face of the membrane by providing a scaffold for a variety of proteins. In this review, several aspects of spectrin organization are highlighted, particularly with respect to its ability to bind hydrophobic ligands and its interaction with membrane surfaces. The characteristic binding of the fluorescent hydrophobic probes Prodan and pyrene to spectrin, which allows an estimation of the polarity of the hydrophobic probe binding site, is illustrated. In addition, the contribution of uniquely localized and conserved tryptophan residues in the 'spectrin repeats' in these processes is discussed. A functional implication of the presence of hydrophobic binding sites in spectrin is its recently discovered chaperone-like activity. Interestingly, spectrin exhibits residual structural integrity even after denaturation which could be considered as a hallmark of cytoskeletal proteins. Future research could provide useful information about the possible role played by spectrin in cellular physiology in healthy and diseased states.
Collapse
Affiliation(s)
- Abhijit Chakrabarti
- Biophysics Division, Saha Institute of Nuclear Physics, Kolkata 700 064, India.
| | | | | |
Collapse
|
13
|
Affiliation(s)
- Devaki A Kelkar
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | | |
Collapse
|
14
|
Kelkar DA, Chattopadhyay A. Monitoring ion channel conformations in membranes utilizing a novel dual fluorescence quenching approach. Biochem Biophys Res Commun 2006; 343:483-8. [PMID: 16546136 DOI: 10.1016/j.bbrc.2006.02.163] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Accepted: 02/24/2006] [Indexed: 10/24/2022]
Abstract
The linear peptide gramicidin forms prototypical ion channels specific for monovalent cations and has been extensively used to study the organization, dynamics, and function of membrane-spanning channels. We have analyzed the localization of the functionally important tryptophan residues of the membrane-bound channel and non-channel conformations of gramicidin utilizing a novel dual fluorescence quenching approach [G.A. Caputo, E. London, Biochemistry 42 (2003) 3265-3274]. In this paper, we show for the first time that the dual quenching approach is applicable to multiple tryptophan containing functional ion channel peptides such as gramicidin. Importantly, dual quenching is found to be sensitive to the membrane-bound conformations of this important model ion channel.
Collapse
Affiliation(s)
- Devaki A Kelkar
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | | |
Collapse
|
15
|
Chattopadhyay A, Arora A, Kelkar DA. Dynamics of a membrane-bound tryptophan analog in environments of varying hydration: a fluorescence approach. Eur Biophys J 2005; 35:62-71. [PMID: 16184387 DOI: 10.1007/s00249-005-0009-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Revised: 06/30/2005] [Accepted: 07/18/2005] [Indexed: 11/24/2022]
Abstract
Tryptophan octyl ester (TOE) represents an important model for membrane-bound tryptophan residues. In this article, we have employed a combination of wavelength-selective fluorescence and time-resolved fluorescence spectroscopies to monitor the effect of varying degrees of hydration on the dynamics of TOE in reverse micellar environments formed by sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in isooctane. Our results show that TOE exhibits red edge excitation shift (REES) and other wavelength-selective fluorescence effects when bound to reverse micelles of AOT. Fluorescence parameters such as intensity, emission maximum, anisotropy, and lifetime of TOE in reverse micelles of AOT depend on [water]/[surfactant] molar ratio (w (o)). These results are relevant and potentially useful for analyzing dynamics of proteins or peptides bound to membranes or membrane-mimetic media under conditions of changing hydration.
Collapse
|
16
|
Rawat SS, Kelkar DA, Chattopadhyay A. Effect of structural transition of the host assembly on dynamics of an ion channel peptide: a fluorescence approach. Biophys J 2005; 89:3049-58. [PMID: 16100280 PMCID: PMC1366802 DOI: 10.1529/biophysj.105.060798] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Structural transition can be induced in charged micelles by increasing the ionic strength of the medium. We have monitored the organization and dynamics of the functionally important tryptophan residues of gramicidin in spherical and rod-shaped sodium dodecyl sulfate micelles utilizing a combination of wavelength-selective fluorescence and related fluorescence approaches. Our results show that tryptophans in gramicidin, present in the single-stranded beta(6.3) conformation, experience slow solvent relaxation giving rise to red edge excitation shift in spherical and rod-shaped micelles. In addition, changes in fluorescence polarization with increasing excitation or emission wavelength reinforce that the gramicidin tryptophans are localized in motionally restricted regions of these micelles. Fluorescence quenching experiments using acrylamide as a quencher of tryptophan fluorescence show that there is reduced water penetration in rod-shaped micelles. Taken together, we show that gramicidin conformation and dynamics is sensitive to the salt-induced structural transition in charged micelles. In addition, these results demonstrate that deformation of the host assembly could modulate protein conformation and dynamics.
Collapse
Affiliation(s)
- Satinder S Rawat
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | | | | |
Collapse
|
17
|
|
18
|
Abstract
We have monitored the membrane-bound channel and nonchannel conformations of gramicidin utilizing red-edge excitation shift (REES), and related fluorescence parameters. In particular, we have used fluorescence lifetime, polarization, quenching, chemical modification, and membrane penetration depth analysis in addition to REES measurements to distinguish these two conformations. Our results show that REES of gramicidin tryptophans can be effectively used to distinguish conformations of membrane-bound gramicidin. The interfacially localized tryptophans in the channel conformation display REES of 7 nm whereas the tryptophans in the nonchannel conformation exhibit REES of 2 nm which highlights the difference in their average environments in terms of localization in the membrane. This is supported by tryptophan penetration depth measurements using the parallax method and fluorescence lifetime and polarization measurements. Further differences in the average tryptophan microenvironments in the two conformations are brought out by fluorescence quenching experiments using acrylamide and chemical modification of the tryptophans by N-bromosuccinimide. In summary, we report novel fluorescence-based approaches to monitor conformations of this important ion channel peptide. Our results offer vital information on the organization and dynamics of the functionally important tryptophan residues in gramicidin.
Collapse
|
19
|
Kelkar DA, Chattopadhyay A, Chakrabarti A, Bhattacharyya M. Effect of ionic strength on the organization and dynamics of tryptophan residues in erythroid spectrin: A fluorescence approach. Biopolymers 2005; 77:325-34. [PMID: 15648086 DOI: 10.1002/bip.20233] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The ionic strength of the medium plays an important role in the structure and conformation of erythroid spectrin. The spectrin dimer is a flexible rod at physiological ionic strength. However, lower ionic strength results in elongation and rigidification (stiffening) of spectrin as shown earlier by electron microscopy and hydrodynamic studies. The ionic strength induced structural transition does not involve any specific secondary structural changes. In this article, we have used a combination of fluorescence spectroscopic approaches that include red edge excitation shift (REES), fluorescence quenching, time-resolved fluorescence measurements, and chemical modification of the spectrin tryptophans to assess the environment and dynamics of tryptophan residues of spectrin under different ionic strength conditions. Our results show that while REES, fluorescence anisotropy, lifetime, and chemical modification of spectrin tryptophans remain unaltered in low and high ionic strength conditions, quenching of tryptophan fluorescence by the aqueous quencher acrylamide (but not the hydrophobic quencher trichloroethanol) and resonance energy transfer to a dansyl-labeled fatty acid show differences in tryptophan environment. These results, which report tertiary structural changes in spectrin upon change in ionic strength, are relevant in understanding the molecular details underlying the conformational flexibility of spectrin.
Collapse
Affiliation(s)
- Devaki A Kelkar
- Centre for Cellular and Molecular Biology, Hyderabad 500 007, India
| | | | | | | |
Collapse
|
20
|
Abstract
Water plays an important role in determining the folding, structure, dynamics, and, in turn, the function of proteins. We have utilized a combination of fluorescence approaches such as the wavelength-selective fluorescence approach to monitor the effect of varying degrees of hydration on the organization and dynamics of the functionally important tryptophan residues of gramicidin in reverse micelles formed by sodium bis(2-ethylhexyl) sulfosuccinate. Our results show that tryptophans in gramicidin, present in the single-stranded beta6.3 conformation, experience slow solvent relaxation giving rise to red-edge excitation shift (REES). In addition, changes in fluorescence polarization with increasing excitation or emission wavelength reinforce that the gramicidin tryptophans are localized in motionally restricted regions of the reverse micelle. Interestingly, the extent of REES is found to be independent of the [water]/[surfactant] molar ratio (w(o)). We attribute this to heterogeneity in gramicidin tryptophan localization. Fluorescence intensity and mean fluorescence lifetime of the gramicidin tryptophans show significant reductions with increasing w(o) indicating sensitivity to increased polarity. Since the dynamics of hydration is related to folding, structure, and eventually function of proteins, we conclude that REES could prove to be a potentially sensitive tool to explore the dynamics of proteins under conditions of changing hydration.
Collapse
|
21
|
Chattopadhyay A, Rawat SS, Kelkar DA, Ray S, Chakrabarti A. Organization and dynamics of tryptophan residues in erythroid spectrin: novel structural features of denatured spectrin revealed by the wavelength-selective fluorescence approach. Protein Sci 2004; 12:2389-403. [PMID: 14573853 PMCID: PMC2366958 DOI: 10.1110/ps.03302003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We have investigated the organization and dynamics of the functionally important tryptophan residues of erythroid spectrin in native and denatured conditions utilizing the wavelength-selective fluorescence approach. We observed a red edge excitation shift (REES) of 4 nm for the tryptophans in the case of spectrin in its native state. This indicates that tryptophans in spectrin are localized in a microenvironment of restricted mobility, and that the regions surrounding the spectrin tryptophans offer considerable restriction to the reorientational motion of the water dipoles around the excited state tryptophans. Interestingly, spectrin exhibits a REES of 3 nm even when denatured in 8 M urea. This represents the first report of a denatured protein displaying REES. Observation of REES in the denatured state implies that some of the structural and dynamic features of this microenvironment around the spectrin tryptophans are retained even when the protein is denatured. Fluorescence quenching data of denatured spectrin support this conclusion. In addition, we have deduced the organization and dynamics of the hydrophobic binding site of the polarity-sensitive fluorescent probe PRODAN that binds erythroid spectrin with high affinity. When bound to spectrin, PRODAN exhibits a REES of 9 nm. Because PRODAN binds to a hydrophobic site in spectrin, such a result would directly imply that this region of spectrin offers considerable restriction to the reorientational motion of the solvent dipoles around the excited state fluorophore. The results of our study could provide vital insight into the role of tryptophans in the stability and folding of spectrin.
Collapse
|
22
|
Affiliation(s)
- Devaki A. Kelkar
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | | |
Collapse
|
23
|
|